Chicory/Radicchio

Common chicory – Cichorium intybus; Wild chicory – Cicoria selvatica

Chicory, like lettuce and endive, is a member of the dandelion family, Asteraceae.

Chicory/Radicchio

Introduction

Chicory, like lettuce and endive, is a member of the dandelion family, Asteraceae. This heritage hints at what is holding it back from being as widely grown as I feel it deserves to be. Most chicory leaves are bitter, but heads of radicchio less so.

Chicory is not well understood as a vegetable, in the UK at least. This is perhaps the most ‘complicated’ of the guides, unless you already grow it and are familiar with chicory’s possibilities.

Four striking chicory hearts in late October
Beautiful Treviso and Tardive chicories outside in mid-December
Some sparkling Treviso chicory in a frost on 26th November

In Italy, where much chicory breeding has happened and continues to happen, there is a liking for bitter leaves and an interest in growing them. Contrast that to the UK where, until recently at least, chicory was barely eaten and even less grown.

  • Recent breeding has helped, because you can now buy seeds of varieties that grow a reliable head, without forcing. Their radicchio is full of tasty, bittersweet leaves, which also store really well.

Large chicory plants with developing heads can be mistaken for cabbage. It’s a false comparison! For one thing, chicory leaves have fewer holes because they suffer fewer pests compared to brassicas.

The main issue is sowing them at the correct times. Chicory flowers in the spring, so first sowings are made after that time. They do not flower in summer and autumn, except for any premature bolting.

Harvest period

  • Days from seed to first harvest: 30 for leaf chicory, 75-150 for radicchio, up to 250 for forced chicory.
  • Best climate is with summers not too hot, say afternoons of 21–33 °C/70–91 °F, with occasional rain or storms.

In the UK at least, there is a muddle about exactly what chicory is, which bits you eat, how you may or may not need to force them, and how you process them for eating.

Below we have a look at the possible harvests from the different types.

  • Among them you will notice some vegetables which are also called or known as endive.
  • Chicory and endive are closely related.

There is much background information here, which is useful to know for achieving best results in growing.

A bountiful 28 kg/62 lb salad harvest in November, of which 24 kg/53 lb was grown outdoors – about a third of the weight is radicchio leaves
My delicious October salad of radicchio Lusia, chicory, carrot, apple, parsnip, onion, garlic and walnut
Some impressive roasted chicories – sugarloaf are the long pale ones, and Palla Rossa have the dark leaves

A range of harvests

Wild chicory grows in pastures and hedgerows, has bitter green leaves, and then flowers in its second spring, with pretty blue flowers by early summer.

Leaf chicory is the result of varietal selection for leaves of varied colour, such as Catalogna chicory with long serrated leaves, known as dandelion greens. There is also a large and serrated Catalogna lettuce variety, which grows leaves of a similar appearance that are less bitter.

  • This lesson is mostly about growing radicchio heads, in order to have chicory harvests with some sweetness to balance the bitter, and for leaves with a firm texture.
  • If you want to grow leaf chicory, space plants three times as close as for heads, or sow in 15 cm/6 in rows, 5 cm/2 in apart, and pick or cut regularly.
  • Grow Ingegnoli’s Self-Blanching for less bitter leaves (from Real Seeds).
These leaf chicories, outdoors on 25th March, were transplanted in August – see the distinctive Grumolo Verde on the right
Treviso Tardivo, a chicory for radicchio in autumn and winter, but here shown growing outside in mid-March; it now has a leaf habit, with the colour disappearing fast

Radicchio is the word for a head of varied colour, shape and density, ideally tight and therefore somewhat blanched and sweeter. The easiest ones to grow are from varieties that automatically fold into tight heads. This happens in autumn, their natural season, and without any forcing process.

Heads vary in shape and colour. The two main types are Palla Rossa and Treviso.

Palla Rossa – the best of a varied harvest from Franchi Seeds, variety Marzatica; they were sown in July and this is December
Sugarloaf chicory in mid-October, three months from sowing and not yet making firm heads; harvests were through November until mid-December
Trimmed heads of Treviso in mid-December – these are the reliable 206TT, and have grown outside from a July sowing

Forced chicory, also called ‘chicon’ and ‘Belgian endive’, is a medium-sized radicchio, from the Witloof variety. It is grown in darkness, thus blanched pale yellow in colour, and is more sweet than bitter.

Chicory root can be eaten. A variety called ‘Chiavari’ Root Chicory is long, thin and white, is best sown in early summer.

Chicory coffee is from roasted roots of Magdeburg chicory, and it continues the bitter theme. After Prussian troops invaded France in 1870, under Bismarck, he went to a café and asked for all the chicory to be brought out, and placed on the table in front of him. Then he asked that they make the coffee!

I like the dry bitterness of some roasted chicory in my coffee, and used to add it to the coffee pot when living in France. In the UK however, it’s not often available in dry form, but sells as liquid ‘Camp Coffee’.

Witloof chicory in September is for forcing – you can see how the roots are enlarging
For forcing – placing one large Witllof root in a pot in late November; it then went into a dark cupboard in the house
1st January – these Treviso have been forced in the house in almost complete darkness

Is chicory a lettuce?

Chicory is in the lettuce family, along with dandelions. Here are chicory comparisons with lettuce:

  • Chicory leaves are much higher in dry matter, so they store well.
  • The season of growth is hugely different because chicory flowers in spring. Therefore its best sowing season is from early summer, and not in the spring.
  • Leaf texture is shinier compared to lettuce, so the colours are brighter.
  • Chicory does not suffer root aphid or leaf mildew, both of which make it a stronger plant than lettuce for growing in late summer and autumn.

Six main types of radicchio, and varieties

There are not many named varieties which I recommend, having tried a lot of them! I urge you to be cautious of beautiful photos on seed packets, which may raise your hopes too much.

Rosso di Chioggia

A round, red Palla Rossa (red ball) type, and the best-known chicory outside Italy. I have grown them for decades, with irregular hearting, except when using hybrid seed such as F1 Indigo.

Almost all the Palla Rossa varieties I grew were incredibly variable in the development of heads, with many forming small ones, if at all. The few larger heads then started to rot within ten days.

Then I discovered 506TT* and it was a revelation. Over the last three years I feel confident that every planting will succeed to about 90%, for decent sized heads which stand well.

*TT derives from the T&T seed company of Chioggia in the Veneto, NE Italy.

Even 506TT varies a lot – it’s a common trait of chicory that there isn’t much uniformity, even when sown on the same day
See the range of colours in these Palla Rossa 706TT hearts of late chicory radicchio
These freshly harvested chicory radicchio, 506TT and 706TT, still have roots on and can be stored in a tray in the shed for up to a month

Rosso di Treviso Precoce

A Treviso which matures to a head in the garden before winter, without any need for forcing. For 33 years I barely succeeded with Treviso chicories when I grew the Franchi varieties, for example, a seed company that is family run and based in Italy. They supply the British company Seeds of Italy.

I felt so blessed to then discover 206TT. After 35 years of attempting to grow Treviso chicory, I was actually harvesting beautiful long heads of lovely flavour, with only a little bitterness. They are excellent in the salad mix because of their crunchy texture, and the leaves are not too big. For roasting, they are simply a treat.

Treviso Tardivo

This is more complicated because it involves forcing. Again, I struggled with the Franchi seeds because it is not clear on their packet that this is a forcing chicory. Their photo suggests to me that at least that you can grow lovely heads of Treviso in the field, late in the season.

I discovered on YouTube that they are harvested in late autumn and brought into sheds, where the roots sit on benches with running water around their lower part. New growth is in darkness, so there is a lovely blanched effect to the heads, after much peeling and trimming. To replicate this at home would be difficult!

Here I am forcing Verona as an example:

In early December, these Rossa di Verona have been grown for forcing and, despite being sown five months earlier, are providing hardly any harvest of hearts
Verona chicory rootballs for forcing
Now time for the main event; for forcing – a tray layered with compost, Treviso chicory roots and then more compost on top
Seven weeks later – the Verona roots are looking great; they were in the half-lit shed and are now growing a few too many chicons, which is keeping them at a small size

Variegato di Castelfranco

Called the Tulip of Winter because of a beautiful leaf formation in its head, Castelfranco heads are slightly loose, helping them to be hardy to frost. The sowing date must be early enough to enable a large enough plant before winter, but not too early. Otherwise, the folded in leaves happen before winter. Later sown plants survive winter weather better, for welcome (though small) heads in cold and dark conditions.

The most dramatic aspect of Castelfranco is their leaf colour, because on the background of pale green there are dashes of vivid orange, yellow and pink. These become more intense towards the centre of any head, like a vivid sunset. They are a warming sight indeed in wintertime.

  • Variegata da Lusia is a variety of Castelfranco, making tighter heads in autumn rather than early winter. Lusia’s heads mostly do not stand well, before rotting. But they are gorgeous to behold and mild to eat.
Variegata da Lusia heart leaves in mid-December
11th January – this Variegata da Lusia is suffering from frost damage; these were picked four weeks earlier due to bitter weather in December, then stored in a shed
The same plants looked like this after trimming the rotting outer leaves – amazing winter heads, though not heavy

Rosso di Verona

With this type also, hearts do not form outside in the way shown on seed packets. Through many years of trying, the best result I had was rather insignificant and open heads. They had lovely quality and colour, but in too small an amount to justify the time and space needed.

Verona regrowth outside in late January – the first growth was cleared for a small harvest in December

Last December I decided to cut off the tops and dig out the roots, to transplant into a tray of compost, not too deep. The tray was in my tin shed, not ideal for forcing because there is some daylight and some frost. See above for a later result too, after another 13 days.

Treviso chicory for forcing – here I’ve just added compost on top of the roots
These forced Rossa di Verona roots were planted in a tray and kept dark in the shed for 29 days beforehand
The same day – these forced Treviso can now be thinned

Rose del Veneto

This is like a pink sister to Verona, with equally small harvests and intended for forcing. They are even more beautiful for being pink rather than dark red. I would say this and the Verona are not for amateur gardeners, unless you have a lot of spare time and space. In that case, they are fun to grow!

(Information on the above six types is helped by chicoryweek.com.)

Pan di Zucchero/Sugarloaf chicory

This has a drawback – it is very pale in colour. Leaves are perhaps a little papery in texture and less crisp than other radicchios.

Yet the folded-in central leaves are sweet indeed, a real treat in autumn and superb roasted as well. Sow and grow as for all radicchio – heads are large and can weigh over 1 kg/2.2 lb from sowing in late June.

See the variability of heading in these Sugarloaf chicories
The last few Sugarloaf chicories sitting in a December frost
A Sugarloaf chicory head and middle leaves, on 19th December

Puntarelle (also known as Catalogna de Galatina)

A large plant that is grown for the young, hollow-stemmed flowering shoots, rather than leaves. The shoots develop into dense beautiful buds with many points, like thin broccoli. Upon harvest, they are separated and julienned into thin strips, then soaked in cold water for a few hours to remove some bitterness.

They develop an elegant curl and the texture is crisp – either eat raw or, more commonly, cooked. A delicacy of the Roman region, where it is highly esteemed.

Puntarelle chicory making a shoot in late October – I had transplanted it in early August after a cabbage harvest
Some lovely shoots of Puntarelle chicory, outside on 23rd October
A bowl of elegant Puntarelle chicory after being soaked in icy water

Suitable for containers/shade?

Chicory grows well in shade, and in containers too. Heads will be smaller because, to achieve a large radicchio, you need a decent amount of large leaves preceding it. Don’t expect a huge harvest, but still a worthwhile one. Especially because you can grow them after, say, a harvest of potato, French beans or lettuce.

Chicory for leaves is more worthwhile in containers, as long as you like bitter leaves!

For bitter leaves through winter in the greenhouse, unheated, these are Palla Rossa, Frenzy endive and Castelfranco Salad King

Video

Grow chicory for radicchio – succession planting

Sow and propagate

The propagation methods are similar to lettuce. The main difference is in timings.

  • Seeds germinate in three to five days, reaching full two-leaf stage within a week.

Sowing conditions

Chicory seedlings germinate and grow in summer warmth. Under cover works well, with no worries about heat being excessive, unlike with lettuce. You can also sow in drills outside.

Pintone 706TT chicories, nine days after sowing on 13th July, then pricked into different potting composts – Dalefoot on the left and Moorland Gold on the right
Now 1st August – the propagation compost trial is already showing a difference between the composts
By 12th August we had already planted out some of the Moorland Gold chicories – the others did not make it in time, showing the value of good potting compost; since then, Dalefoot have amended their mix and it’s better!

Sowing time

Timing requires precision, so I am giving the dates by month name rather than season.

First sowings here are in early June. If I sow even in late May, some of the plants bolt in August before making firm heads. If I sow after 26th July, plants grow fine but run out of time to make firm heads.

  • Sowings from 8th–15th June give harvests in late August until early October.
  • Sowings in late June to early July give harvests through autumn.
  • Sowings in the second week of July give heads in late autumn to early winter, good for storage through winter.
  • A small sowing as late as 20th–23rd July gives smaller heads in winter and even in January.
  • Sowings for chicory to force are best from late May to mid-June.

Sowing method

Either sow in trays for pricking individual seedlings into module cells, or sow two seeds per cell and thin to the strongest. There should be no need for potting on, unless, say, you are waiting for a harvest to happen, such as onions, potatoes, beetroot etc.

A seed tray in July – brokali on the left, fennel in the middle that’s yet to appear, and some chicory on the right, which has already given seedlings to prick out
11th July – five days after sowing I am pricking out these chicory seedlings
Sugarloaf chicory on 30th December – this one was planted too late, with no head; still good to eat though

Transplant

Transplant size

Around 5 cm/2 in wide and high is good – this is often three weeks from sowing. Small transplants succeed best.

A morning view on 23rd July – mid-way through removing onions, to be replaced by chicory plants; we have already filled four crates with onions from this bed
Later that day, the chicory have been planted out – two people in a one-hour session
13th August – the chicory bed is fourth from the left and already looking pretty full after just three weeks of growth, with no top-ups of feed or compost

Transplant time and method

You are often transplanting into dry soil in summer, and after a preceding harvest that has taken a lot of moisture.

  • You may need to water a bed before even making any holes.
  • Dib deep holes as for any salad plant, a little deeper than the module.
  • Push rootballs in firmly, and water them thoroughly.

Spacing

30 cm/12 in is the main spacing I use and recommend. You can space at 35 cm/14 in for larger heads and a slightly later harvest, also to grow larger roots for forcing.

30th July – these chicory have just been planted out at 30 cm/12 in spacings; they will provide a lovely harvest of radicchio from mid-autumn
Sixty days later looking over the same chicories, many of which are now ready to be harvested for radicchio hearts

Water

How often

New plantings often need watering every day or second day until you can see strong new growth, the best indication that roots have established. If the weather continues dry and warm after that, water about twice a week until it rains and autumn arrives.

How much

Give a medium amount of water. Chicory plants are not huge but they grow fast, and head size is much influenced by moisture level, especially in the final third of their life. At the spacings I recommend, leaves will be touching each other and filling all the space within four weeks.

A hot summers day on 26th July – these 18-day-old chicory plants are being planted out into a pre-watered bed that has just been cleared of broccoli
Five weeks later, the chicory beds are thriving, with the help of our watering – the water is needed whether or not the surface had, say, straw on top, because the soil had been emptied of moisture by preceding vegetables

Extra mulch to retain moisture?

Do this in dry climates only, because slugs can breed quickly in the dampness under mulches such as straw. Chicory plants grow fast and do a fine job of mulching the surface with their leaves.

Leaf removal

You don’t need to do a lot of this – mainly just at the stage when outer leaves are pushing against each other because all the ground is covered. This is within a month from transplanting. Do a second tidying after eight weeks or so from the transplant date, to keep slug numbers low.

Twist off several lower and outermost leaves. Many will be decaying and you may find yourself removing large slugs. Also, you may notice a few heads already developed.

Harvest times and methods

How to judge the readiness of radicchio

About ten weeks after sowing, watch for leaves folding in around developing heads. They are less obvious than cabbage, for example, and it’s difficult to know how dense they are just by looking.

  • Use your fingers to push into heads and feel if they are soft or firm.
  • Best harvests are when they feel reasonably solid.
  • If you wait more than two to three weeks after that, there is a risk of some decay on heads’ outer leaves.
16th August – I am able to cut a few early radicchio; these 506TT were sown 71 days earlier and planted out on 29th June
1st November – the first few of these 506TT radicchio are ready, sown on 5th July
This is the final harvest of radicchio 506 and 706TT plants in mid-December, sown on 13th July – here we have around 46 kg/101 lb of trimmed heads

How to pick

This depends on what you hope for after harvesting the head.

  1. An option is to leave roots in the ground, for secondary harvests of much smaller heads. They are side shoots that grow out of the main stem.  Simply cut just below head level for your radicchio, and trim off outer leaves until you have a nice head. Next, at ground level, remove any decaying lower leaves, so that within one or two months you will see new but small shoots. They keep appearing until spring, depending on your climate.
  2. When your aim is to clear the ground, harvest by grasping a plant with both hands, outer leaves and all. Gently rotate it, with a slight pull. This removes just the central cluster of larger roots and leaves most in the soil. Trim those roots and the outer leaves to find your radicchio.
Mid-November – these Luisa chicory will still make heads that are firmer than this, or just grow a little more, so there is no rush to harvest
Harvesting Sugarloaf chicory between October and December
The second crop of chicory plants, grown in beds previously occupied by onions and peas until midsummer

Roots to force

Use a sharp spade pushed vertically down and close to the main root, then lever while pulling on the root’s shoulder. Do this in late autumn to early winter, before frosts colder than about –6 °C/21 °F.

Place the roots in pots or trays, with only enough compost that they stay moist. Use any tray and pack them in, at 15–20 cm/6–8 in apart – the closer spacing is for smaller roots.

3rd January – thinning chicons from Witloof roots, planted here in 30 cm/12 in of homemade compost
17 days later, with fully grown forced chicons from Witloof roots, 30 days in a house cupboard at 15 °C/60 °F
20th January – the chicon harvest is complete for now; they were 135 g/5 oz in weight; secondary growth is smaller and also longer
Treviso chicory for forcing – here I’ve just added compost on top of the roots
These forced Rossa di Verona roots were planted in a tray and kept dark in the shed for 29 days beforehand
The same day – these forced Treviso can now be thinned

Storing

Firm heads store well. Be sure there are no rotting leaves on the outside, and place them in boxes or crates to keep anywhere cool and damp. In my brick shed, with temperatures -1–10 °C/30–50 °F through winter, they store for up to six weeks.

Before eating them, you need to trim off a few decaying outer leaves. Slow growth continues in stored heads, with their central stem elongating as it moves towards flowering. So the number of usable leaves decreases all the time.

These chicory radicchio have been quartered, ready to be separated into leaves and added to a salad mix
180 days since these were sown – there are side shoots on this over-mature 506TT radicchio
At the winter solstice, chicory 506TT and 706TT were harvested 13 days earlier and stored in the tray with roots on; in the black tray are trimmed stems of Treviso 206TT, showing the fractal patterns of the stalks
Treviso Precoce 206TT in late October, sown in early July
Six days later I found an apparently rotting plant, but some peeling revealed a lovely head that remained underneath
There are a few harvested heads of Pintone TT which are darker than the 206TT Treviso

Saving seed

I have not tried this yet but I want to. I have not found information about how many plants you need for pollination to be successful. In 2020 I succeeded with just one plant of endive (a close relative of chicory), with subsequent growth through winter being strong and even.

This suggests there was no inbreeding from only one plant producing the seed, which is the case with lettuce. I think that chicory may be the same.

See more on Real Seeds UK website.

Potential problems

Which pests are likely, and when

  • Slugs eat the tender leaves of new seedlings and the decaying leaves of older plants.
  • Rabbits eat seedling leaves and any part of all plants.
  • Deer chew out the central head of mature plants, your precious radicchio, and also chew the ends of outer leaves.
This chicory plant has been well nibbled by a deer

Protections needed

Bird netting is the best and easiest protection since you do not need to protect against insects. Use hoops to hold the netting above new plantings.

If the pests are deer, who graze larger plants, it’s sufficient simply to lay netting on top of all plants. Deer do not chew through it, in my experience.

Other likely difficulties

There are few. Bolting can be an issue, from sowing too early – wait until summer begins before you sow seeds.

And finally

Clear

See ‘How to pick’ above. The main point is that any stem with its root system left in the soil will usually survive winter while growing more small chicory leaves, and then develop flower stems through spring. It’s fine to leave many small roots in the soil.

Follow with

Harvests are in autumn and there is usually not time to follow with new plantings. My normal process after plantings is to mulch beds with compost for the year ahead.

Variations could be to sow or transplant broad beans and garlic.

Or, after earlier harvests of chicory sown by mid-June, there is time (just) either to transplant autumn salads, or to sow a cover crop.

In 2020 I compared sowings on 1st October of buckwheat (Fagopyrum esculentum) and white mustard (Synapsis alba).

  • The buckwheat barely grew before it was killed by a slight frost in early November. Clearly it needs sowing earlier, by mid-September at the latest. What I had read about its sowing dates was unclear.
  • Meanwhile the mustard grew strongly, and we even took several harvests from its tops for salad leaves, from late October through November. Then it was killed by -5 °C/23 °F frosts by mid-January.
White mustard, sown on 1st October when the summer-planted radicchios had finished; this is after we had cut the tips on 29th October, returning two buckets worth for salad mix
Also 1st October – I sowed some buckwheat in a bed after clearing beetroot; compared to the mustard, there are hardly any leaves, and four days after this there were none, following a slight frost which killed the buckwheat seedlings but not the mustard

Chicory/Radicchio

Common chicory – Cichorium intybus; Wild chicory – Cicoria selvatica

Chicory, like lettuce and endive, is a member of the dandelion family, Asteraceae.

Chicory/Radicchio

Introduction

Chicory, like lettuce and endive, is a member of the dandelion family, Asteraceae. This heritage hints at what is holding it back from being as widely grown as I feel it deserves to be. Most chicory leaves are bitter, but heads of radicchio less so.

Chicory is not well understood as a vegetable, in the UK at least. This is perhaps the most ‘complicated’ of the guides, unless you already grow it and are familiar with chicory’s possibilities.

Four striking chicory hearts in late October
Beautiful Treviso and Tardive chicories outside in mid-December
Some sparkling Treviso chicory in a frost on 26th November

In Italy, where much chicory breeding has happened and continues to happen, there is a liking for bitter leaves and an interest in growing them. Contrast that to the UK where, until recently at least, chicory was barely eaten and even less grown.

  • Recent breeding has helped, because you can now buy seeds of varieties that grow a reliable head, without forcing. Their radicchio is full of tasty, bittersweet leaves, which also store really well.

Large chicory plants with developing heads can be mistaken for cabbage. It’s a false comparison! For one thing, chicory leaves have fewer holes because they suffer fewer pests compared to brassicas.

The main issue is sowing them at the correct times. Chicory flowers in the spring, so first sowings are made after that time. They do not flower in summer and autumn, except for any premature bolting.

Harvest period

  • Days from seed to first harvest: 30 for leaf chicory, 75-150 for radicchio, up to 250 for forced chicory.
  • Best climate is with summers not too hot, say afternoons of 21–33 °C/70–91 °F, with occasional rain or storms.

In the UK at least, there is a muddle about exactly what chicory is, which bits you eat, how you may or may not need to force them, and how you process them for eating.

Below we have a look at the possible harvests from the different types.

  • Among them you will notice some vegetables which are also called or known as endive.
  • Chicory and endive are closely related.

There is much background information here, which is useful to know for achieving best results in growing.

A bountiful 28 kg/62 lb salad harvest in November, of which 24 kg/53 lb was grown outdoors – about a third of the weight is radicchio leaves
My delicious October salad of radicchio Lusia, chicory, carrot, apple, parsnip, onion, garlic and walnut
Some impressive roasted chicories – sugarloaf are the long pale ones, and Palla Rossa have the dark leaves

A range of harvests

Wild chicory grows in pastures and hedgerows, has bitter green leaves, and then flowers in its second spring, with pretty blue flowers by early summer.

Leaf chicory is the result of varietal selection for leaves of varied colour, such as Catalogna chicory with long serrated leaves, known as dandelion greens. There is also a large and serrated Catalogna lettuce variety, which grows leaves of a similar appearance that are less bitter.

  • This lesson is mostly about growing radicchio heads, in order to have chicory harvests with some sweetness to balance the bitter, and for leaves with a firm texture.
  • If you want to grow leaf chicory, space plants three times as close as for heads, or sow in 15 cm/6 in rows, 5 cm/2 in apart, and pick or cut regularly.
  • Grow Ingegnoli’s Self-Blanching for less bitter leaves (from Real Seeds).
These leaf chicories, outdoors on 25th March, were transplanted in August – see the distinctive Grumolo Verde on the right
Treviso Tardivo, a chicory for radicchio in autumn and winter, but here shown growing outside in mid-March; it now has a leaf habit, with the colour disappearing fast

Radicchio is the word for a head of varied colour, shape and density, ideally tight and therefore somewhat blanched and sweeter. The easiest ones to grow are from varieties that automatically fold into tight heads. This happens in autumn, their natural season, and without any forcing process.

Heads vary in shape and colour. The two main types are Palla Rossa and Treviso.

Palla Rossa – the best of a varied harvest from Franchi Seeds, variety Marzatica; they were sown in July and this is December
Sugarloaf chicory in mid-October, three months from sowing and not yet making firm heads; harvests were through November until mid-December
Trimmed heads of Treviso in mid-December – these are the reliable 206TT, and have grown outside from a July sowing

Forced chicory, also called ‘chicon’ and ‘Belgian endive’, is a medium-sized radicchio, from the Witloof variety. It is grown in darkness, thus blanched pale yellow in colour, and is more sweet than bitter.

Chicory root can be eaten. A variety called ‘Chiavari’ Root Chicory is long, thin and white, is best sown in early summer.

Chicory coffee is from roasted roots of Magdeburg chicory, and it continues the bitter theme. After Prussian troops invaded France in 1870, under Bismarck, he went to a café and asked for all the chicory to be brought out, and placed on the table in front of him. Then he asked that they make the coffee!

I like the dry bitterness of some roasted chicory in my coffee, and used to add it to the coffee pot when living in France. In the UK however, it’s not often available in dry form, but sells as liquid ‘Camp Coffee’.

Witloof chicory in September is for forcing – you can see how the roots are enlarging
For forcing – placing one large Witllof root in a pot in late November; it then went into a dark cupboard in the house
1st January – these Treviso have been forced in the house in almost complete darkness

Is chicory a lettuce?

Chicory is in the lettuce family, along with dandelions. Here are chicory comparisons with lettuce:

  • Chicory leaves are much higher in dry matter, so they store well.
  • The season of growth is hugely different because chicory flowers in spring. Therefore its best sowing season is from early summer, and not in the spring.
  • Leaf texture is shinier compared to lettuce, so the colours are brighter.
  • Chicory does not suffer root aphid or leaf mildew, both of which make it a stronger plant than lettuce for growing in late summer and autumn.

Six main types of radicchio, and varieties

There are not many named varieties which I recommend, having tried a lot of them! I urge you to be cautious of beautiful photos on seed packets, which may raise your hopes too much.

Rosso di Chioggia

A round, red Palla Rossa (red ball) type, and the best-known chicory outside Italy. I have grown them for decades, with irregular hearting, except when using hybrid seed such as F1 Indigo.

Almost all the Palla Rossa varieties I grew were incredibly variable in the development of heads, with many forming small ones, if at all. The few larger heads then started to rot within ten days.

Then I discovered 506TT* and it was a revelation. Over the last three years I feel confident that every planting will succeed to about 90%, for decent sized heads which stand well.

*TT derives from the T&T seed company of Chioggia in the Veneto, NE Italy.

Even 506TT varies a lot – it’s a common trait of chicory that there isn’t much uniformity, even when sown on the same day
See the range of colours in these Palla Rossa 706TT hearts of late chicory radicchio
These freshly harvested chicory radicchio, 506TT and 706TT, still have roots on and can be stored in a tray in the shed for up to a month

Rosso di Treviso Precoce

A Treviso which matures to a head in the garden before winter, without any need for forcing. For 33 years I barely succeeded with Treviso chicories when I grew the Franchi varieties, for example, a seed company that is family run and based in Italy. They supply the British company Seeds of Italy.

I felt so blessed to then discover 206TT. After 35 years of attempting to grow Treviso chicory, I was actually harvesting beautiful long heads of lovely flavour, with only a little bitterness. They are excellent in the salad mix because of their crunchy texture, and the leaves are not too big. For roasting, they are simply a treat.

Treviso Tardivo

This is more complicated because it involves forcing. Again, I struggled with the Franchi seeds because it is not clear on their packet that this is a forcing chicory. Their photo suggests to me that at least that you can grow lovely heads of Treviso in the field, late in the season.

I discovered on YouTube that they are harvested in late autumn and brought into sheds, where the roots sit on benches with running water around their lower part. New growth is in darkness, so there is a lovely blanched effect to the heads, after much peeling and trimming. To replicate this at home would be difficult!

Here I am forcing Verona as an example:

In early December, these Rossa di Verona have been grown for forcing and, despite being sown five months earlier, are providing hardly any harvest of hearts
Verona chicory rootballs for forcing
Now time for the main event; for forcing – a tray layered with compost, Treviso chicory roots and then more compost on top
Seven weeks later – the Verona roots are looking great; they were in the half-lit shed and are now growing a few too many chicons, which is keeping them at a small size

Variegato di Castelfranco

Called the Tulip of Winter because of a beautiful leaf formation in its head, Castelfranco heads are slightly loose, helping them to be hardy to frost. The sowing date must be early enough to enable a large enough plant before winter, but not too early. Otherwise, the folded in leaves happen before winter. Later sown plants survive winter weather better, for welcome (though small) heads in cold and dark conditions.

The most dramatic aspect of Castelfranco is their leaf colour, because on the background of pale green there are dashes of vivid orange, yellow and pink. These become more intense towards the centre of any head, like a vivid sunset. They are a warming sight indeed in wintertime.

  • Variegata da Lusia is a variety of Castelfranco, making tighter heads in autumn rather than early winter. Lusia’s heads mostly do not stand well, before rotting. But they are gorgeous to behold and mild to eat.
Variegata da Lusia heart leaves in mid-December
11th January – this Variegata da Lusia is suffering from frost damage; these were picked four weeks earlier due to bitter weather in December, then stored in a shed
The same plants looked like this after trimming the rotting outer leaves – amazing winter heads, though not heavy

Rosso di Verona

With this type also, hearts do not form outside in the way shown on seed packets. Through many years of trying, the best result I had was rather insignificant and open heads. They had lovely quality and colour, but in too small an amount to justify the time and space needed.

Verona regrowth outside in late January – the first growth was cleared for a small harvest in December

Last December I decided to cut off the tops and dig out the roots, to transplant into a tray of compost, not too deep. The tray was in my tin shed, not ideal for forcing because there is some daylight and some frost. See above for a later result too, after another 13 days.

Treviso chicory for forcing – here I’ve just added compost on top of the roots
These forced Rossa di Verona roots were planted in a tray and kept dark in the shed for 29 days beforehand
The same day – these forced Treviso can now be thinned

Rose del Veneto

This is like a pink sister to Verona, with equally small harvests and intended for forcing. They are even more beautiful for being pink rather than dark red. I would say this and the Verona are not for amateur gardeners, unless you have a lot of spare time and space. In that case, they are fun to grow!

(Information on the above six types is helped by chicoryweek.com.)

Pan di Zucchero/Sugarloaf chicory

This has a drawback – it is very pale in colour. Leaves are perhaps a little papery in texture and less crisp than other radicchios.

Yet the folded-in central leaves are sweet indeed, a real treat in autumn and superb roasted as well. Sow and grow as for all radicchio – heads are large and can weigh over 1 kg/2.2 lb from sowing in late June.

See the variability of heading in these Sugarloaf chicories
The last few Sugarloaf chicories sitting in a December frost
A Sugarloaf chicory head and middle leaves, on 19th December

Puntarelle (also known as Catalogna de Galatina)

A large plant that is grown for the young, hollow-stemmed flowering shoots, rather than leaves. The shoots develop into dense beautiful buds with many points, like thin broccoli. Upon harvest, they are separated and julienned into thin strips, then soaked in cold water for a few hours to remove some bitterness.

They develop an elegant curl and the texture is crisp – either eat raw or, more commonly, cooked. A delicacy of the Roman region, where it is highly esteemed.

Puntarelle chicory making a shoot in late October – I had transplanted it in early August after a cabbage harvest
Some lovely shoots of Puntarelle chicory, outside on 23rd October
A bowl of elegant Puntarelle chicory after being soaked in icy water

Suitable for containers/shade?

Chicory grows well in shade, and in containers too. Heads will be smaller because, to achieve a large radicchio, you need a decent amount of large leaves preceding it. Don’t expect a huge harvest, but still a worthwhile one. Especially because you can grow them after, say, a harvest of potato, French beans or lettuce.

Chicory for leaves is more worthwhile in containers, as long as you like bitter leaves!

For bitter leaves through winter in the greenhouse, unheated, these are Palla Rossa, Frenzy endive and Castelfranco Salad King

Video

Grow chicory for radicchio – succession planting

Sow and propagate

The propagation methods are similar to lettuce. The main difference is in timings.

  • Seeds germinate in three to five days, reaching full two-leaf stage within a week.

Sowing conditions

Chicory seedlings germinate and grow in summer warmth. Under cover works well, with no worries about heat being excessive, unlike with lettuce. You can also sow in drills outside.

Pintone 706TT chicories, nine days after sowing on 13th July, then pricked into different potting composts – Dalefoot on the left and Moorland Gold on the right
Now 1st August – the propagation compost trial is already showing a difference between the composts
By 12th August we had already planted out some of the Moorland Gold chicories – the others did not make it in time, showing the value of good potting compost; since then, Dalefoot have amended their mix and it’s better!

Sowing time

Timing requires precision, so I am giving the dates by month name rather than season.

First sowings here are in early June. If I sow even in late May, some of the plants bolt in August before making firm heads. If I sow after 26th July, plants grow fine but run out of time to make firm heads.

  • Sowings from 8th–15th June give harvests in late August until early October.
  • Sowings in late June to early July give harvests through autumn.
  • Sowings in the second week of July give heads in late autumn to early winter, good for storage through winter.
  • A small sowing as late as 20th–23rd July gives smaller heads in winter and even in January.
  • Sowings for chicory to force are best from late May to mid-June.

Sowing method

Either sow in trays for pricking individual seedlings into module cells, or sow two seeds per cell and thin to the strongest. There should be no need for potting on, unless, say, you are waiting for a harvest to happen, such as onions, potatoes, beetroot etc.

A seed tray in July – brokali on the left, fennel in the middle that’s yet to appear, and some chicory on the right, which has already given seedlings to prick out
11th July – five days after sowing I am pricking out these chicory seedlings
Sugarloaf chicory on 30th December – this one was planted too late, with no head; still good to eat though

Transplant

Transplant size

Around 5 cm/2 in wide and high is good – this is often three weeks from sowing. Small transplants succeed best.

A morning view on 23rd July – mid-way through removing onions, to be replaced by chicory plants; we have already filled four crates with onions from this bed
Later that day, the chicory have been planted out – two people in a one-hour session
13th August – the chicory bed is fourth from the left and already looking pretty full after just three weeks of growth, with no top-ups of feed or compost

Transplant time and method

You are often transplanting into dry soil in summer, and after a preceding harvest that has taken a lot of moisture.

  • You may need to water a bed before even making any holes.
  • Dib deep holes as for any salad plant, a little deeper than the module.
  • Push rootballs in firmly, and water them thoroughly.

Spacing

30 cm/12 in is the main spacing I use and recommend. You can space at 35 cm/14 in for larger heads and a slightly later harvest, also to grow larger roots for forcing.

30th July – these chicory have just been planted out at 30 cm/12 in spacings; they will provide a lovely harvest of radicchio from mid-autumn
Sixty days later looking over the same chicories, many of which are now ready to be harvested for radicchio hearts

Transplant size

Around 5 cm/2 in wide and high is good – this is often three weeks from sowing. Small transplants succeed best.

A morning view on 23rd July – mid-way through removing onions, to be replaced by chicory plants; we have already filled four crates with onions from this bed
Later that day, the chicory have been planted out – two people in a one-hour session
13th August – the chicory bed is fourth from the left and already looking pretty full after just three weeks of growth, with no top-ups of feed or compost

Transplant time and method

You are often transplanting into dry soil in summer, and after a preceding harvest that has taken a lot of moisture.

  • You may need to water a bed before even making any holes.
  • Dib deep holes as for any salad plant, a little deeper than the module.
  • Push rootballs in firmly, and water them thoroughly.

Spacing

30 cm/12 in is the main spacing I use and recommend. You can space at 35 cm/14 in for larger heads and a slightly later harvest, also to grow larger roots for forcing.

30th July – these chicory have just been planted out at 30 cm/12 in spacings; they will provide a lovely harvest of radicchio from mid-autumn
Sixty days later looking over the same chicories, many of which are now ready to be harvested for radicchio hearts

Water

How often

New plantings often need watering every day or second day until you can see strong new growth, the best indication that roots have established. If the weather continues dry and warm after that, water about twice a week until it rains and autumn arrives.

How much

Give a medium amount of water. Chicory plants are not huge but they grow fast, and head size is much influenced by moisture level, especially in the final third of their life. At the spacings I recommend, leaves will be touching each other and filling all the space within four weeks.

A hot summers day on 26th July – these 18-day-old chicory plants are being planted out into a pre-watered bed that has just been cleared of broccoli
Five weeks later, the chicory beds are thriving, with the help of our watering – the water is needed whether or not the surface had, say, straw on top, because the soil had been emptied of moisture by preceding vegetables

Extra mulch to retain moisture?

Do this in dry climates only, because slugs can breed quickly in the dampness under mulches such as straw. Chicory plants grow fast and do a fine job of mulching the surface with their leaves.

Leaf removal

You don’t need to do a lot of this – mainly just at the stage when outer leaves are pushing against each other because all the ground is covered. This is within a month from transplanting. Do a second tidying after eight weeks or so from the transplant date, to keep slug numbers low.

Twist off several lower and outermost leaves. Many will be decaying and you may find yourself removing large slugs. Also, you may notice a few heads already developed.

Harvest times and methods

How to judge the readiness of radicchio

About ten weeks after sowing, watch for leaves folding in around developing heads. They are less obvious than cabbage, for example, and it’s difficult to know how dense they are just by looking.

  • Use your fingers to push into heads and feel if they are soft or firm.
  • Best harvests are when they feel reasonably solid.
  • If you wait more than two to three weeks after that, there is a risk of some decay on heads’ outer leaves.
16th August – I am able to cut a few early radicchio; these 506TT were sown 71 days earlier and planted out on 29th June
1st November – the first few of these 506TT radicchio are ready, sown on 5th July
This is the final harvest of radicchio 506 and 706TT plants in mid-December, sown on 13th July – here we have around 46 kg/101 lb of trimmed heads

How to pick

This depends on what you hope for after harvesting the head.

  1. An option is to leave roots in the ground, for secondary harvests of much smaller heads. They are side shoots that grow out of the main stem.  Simply cut just below head level for your radicchio, and trim off outer leaves until you have a nice head. Next, at ground level, remove any decaying lower leaves, so that within one or two months you will see new but small shoots. They keep appearing until spring, depending on your climate.
  2. When your aim is to clear the ground, harvest by grasping a plant with both hands, outer leaves and all. Gently rotate it, with a slight pull. This removes just the central cluster of larger roots and leaves most in the soil. Trim those roots and the outer leaves to find your radicchio.
Mid-November – these Luisa chicory will still make heads that are firmer than this, or just grow a little more, so there is no rush to harvest
Harvesting Sugarloaf chicory between October and December
The second crop of chicory plants, grown in beds previously occupied by onions and peas until midsummer

Roots to force

Use a sharp spade pushed vertically down and close to the main root, then lever while pulling on the root’s shoulder. Do this in late autumn to early winter, before frosts colder than about –6 °C/21 °F.

Place the roots in pots or trays, with only enough compost that they stay moist. Use any tray and pack them in, at 15–20 cm/6–8 in apart – the closer spacing is for smaller roots.

3rd January – thinning chicons from Witloof roots, planted here in 30 cm/12 in of homemade compost
17 days later, with fully grown forced chicons from Witloof roots, 30 days in a house cupboard at 15 °C/60 °F
20th January – the chicon harvest is complete for now; they were 135 g/5 oz in weight; secondary growth is smaller and also longer
Treviso chicory for forcing – here I’ve just added compost on top of the roots
These forced Rossa di Verona roots were planted in a tray and kept dark in the shed for 29 days beforehand
The same day – these forced Treviso can now be thinned

Storing

Firm heads store well. Be sure there are no rotting leaves on the outside, and place them in boxes or crates to keep anywhere cool and damp. In my brick shed, with temperatures -1–10 °C/30–50 °F through winter, they store for up to six weeks.

Before eating them, you need to trim off a few decaying outer leaves. Slow growth continues in stored heads, with their central stem elongating as it moves towards flowering. So the number of usable leaves decreases all the time.

These chicory radicchio have been quartered, ready to be separated into leaves and added to a salad mix
180 days since these were sown – there are side shoots on this over-mature 506TT radicchio
At the winter solstice, chicory 506TT and 706TT were harvested 13 days earlier and stored in the tray with roots on; in the black tray are trimmed stems of Treviso 206TT, showing the fractal patterns of the stalks
Treviso Precoce 206TT in late October, sown in early July
Six days later I found an apparently rotting plant, but some peeling revealed a lovely head that remained underneath
There are a few harvested heads of Pintone TT which are darker than the 206TT Treviso

Saving seed

I have not tried this yet but I want to. I have not found information about how many plants you need for pollination to be successful. In 2020 I succeeded with just one plant of endive (a close relative of chicory), with subsequent growth through winter being strong and even.

This suggests there was no inbreeding from only one plant producing the seed, which is the case with lettuce. I think that chicory may be the same.

See more on Real Seeds UK website.

Potential problems

Which pests are likely, and when

  • Slugs eat the tender leaves of new seedlings and the decaying leaves of older plants.
  • Rabbits eat seedling leaves and any part of all plants.
  • Deer chew out the central head of mature plants, your precious radicchio, and also chew the ends of outer leaves.
This chicory plant has been well nibbled by a deer

Protections needed

Bird netting is the best and easiest protection since you do not need to protect against insects. Use hoops to hold the netting above new plantings.

If the pests are deer, who graze larger plants, it’s sufficient simply to lay netting on top of all plants. Deer do not chew through it, in my experience.

Other likely difficulties

There are few. Bolting can be an issue, from sowing too early – wait until summer begins before you sow seeds.

And finally

Clear

See ‘How to pick’ above. The main point is that any stem with its root system left in the soil will usually survive winter while growing more small chicory leaves, and then develop flower stems through spring. It’s fine to leave many small roots in the soil.

Follow with

Harvests are in autumn and there is usually not time to follow with new plantings. My normal process after plantings is to mulch beds with compost for the year ahead.

Variations could be to sow or transplant broad beans and garlic.

Or, after earlier harvests of chicory sown by mid-June, there is time (just) either to transplant autumn salads, or to sow a cover crop.

In 2020 I compared sowings on 1st October of buckwheat (Fagopyrum esculentum) and white mustard (Synapsis alba).

  • The buckwheat barely grew before it was killed by a slight frost in early November. Clearly it needs sowing earlier, by mid-September at the latest. What I had read about its sowing dates was unclear.
  • Meanwhile the mustard grew strongly, and we even took several harvests from its tops for salad leaves, from late October through November. Then it was killed by -5 °C/23 °F frosts by mid-January.
White mustard, sown on 1st October when the summer-planted radicchios had finished; this is after we had cut the tips on 29th October, returning two buckets worth for salad mix
Also 1st October – I sowed some buckwheat in a bed after clearing beetroot; compared to the mustard, there are hardly any leaves, and four days after this there were none, following a slight frost which killed the buckwheat seedlings but not the mustard