Salads for Winter

Claytonia perfoliata, Valerianella locusta, Barbara verna

This lesson has a grouping of vegetables that are mostly eaten as salad ingredients and grow rapidly. None of them grow in summer.

Introduction

This lesson has a grouping of vegetables that are mostly eaten as salad ingredients and grow rapidly. None of them grows in summer, and they are from a selection of plant families.

Other salads such as Oriental leaves, plus rocket and lettuce, are in the Chinese cabbage and Oriental leaves I include some photos of them here for comparison purposes, to show their larger leaves and faster regrowth. They are less hardy to frost than the three featured here.

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10th January – corn salad in a -3 °C/27 °F freeze, much stronger than lettuce would be in the same conditions

Four weeks later in February – Valentin lambs lettuce was sown on 14th September and transplanted five weeks later

22nd November – Claytonia, land cress and spinach in the greenhouse, all sown on the same day in September

Three hardy winter salads

1. Claytonia (Claytonia perfoliata)

Claytonia is in the Montiaceae family of flowering plants, native to the Americas, in particular to mountainous regions with moist conditions.

Its colloquial name is winter purslane, but it’s not in the Portulaceae/Purslane family.

It’s also called miners lettuce, from its popularity with miners from two very different locations – it was eaten during the 1849 Californian Gold Rush and by tin miners in Cornwall, UK, who (it is said) picked some from the hedgerows to pop in their pasties, before descending.

2. Corn salad (Valerianella locusta)

Corn salad is native to and wild in much of northern Europe and Africa, then was taken to North America and has escaped to grow wild there. Its German name of ‘Feldsalat’ (field salad) reflects how it grows like a weed in disturbed soil, and the English name ‘corn salad’ likewise originates from it growing after harvests of wheat and barley. Other colloquial names are ‘mâche’ and ‘lambs lettuce’.

3. Land cress (Barbara verna)

Land cress is in the Brassica family, with a pungent mustard flavour very similar to watercress. It’s native to southern Europe and mountainous regions in general, including the Appalachians where it now grows wild. Other names include ‘American land cress’ and ‘upland cress’. It grows in damp soil and is healthiest in the cool of winter.

20th September – showing the contrast of salads in this lesson, with bulkier salads such as rocket and mustards; this is four weeks since transplanting, and we have already picked them twice

Also on 20th September – corn salad is just starting to grow after being sown three weeks earlier

November, and ready for winter – spinach, salad rocket and Claytonia, transplanted a month earlier after clearing runner beans

Harvest period

Days from seed to first harvest: Claytonia – 50, corn salad – 60, land cress – 70

Best climate is temperate, moist, cool more than hot, can be frosty in winter.

Why grow them

A special attribute of these plants is their hardiness to cold, combined with an extraordinary ability to make new growth in conditions when many other plants do not! They give green leaves through winter when fresh greens are so valuable for our health.

Flavour-wise they are very different. Land cress is pungent, corn salad is nutty and with a waxy leaf, while Claytonia is succulent with soft leaves and not a huge flavour. Corn salad has three times more vitamin C than lettuce.

19th January – a selection of outdoor salad leaves including land cress, chervil and beetroot

Outdoor grown leaves in March – land cress, chard and corn salad, plus a plant of the latter on the right

23rd April – land cress flowers are edible and have a strong cress flavour

Pattern of growth

These are not plants I would attempt to sow in spring for harvesting late spring and summer. They are likely to flower, suffer more pests and grow less healthy leaves – mildew on corn salad that you sow before early autumn, for example.

These plants need regular moisture to keep growing, yet mostly have surface roots. This is partly why it is difficult to grow them in summer, because when the surface dries they suffer, from being unable to root deeply for moisture.

The natural season of leaf growth is autumn through winter, from germination in late summer to early autumn. How much they actually grow in winter depends on the weather. They all survive hard frost, colder than -10° C/14° F, but won’t grow in those temperatures. See the work of Pam Dawling in Virginia USA, who has researched the lowest temperatures for vegetable survival.

Flowering time is early spring and you can easily save seeds then, when you have a few plants growing together to ensure cross-pollination.

November, after an unusual flood has washed a little compost off the surface – you can see the surface roots of corn salad

In the greenhouse in December – Claytonia surface rooting over the edge of a tray, which I have just lifted to show this

Outdoor winter salads – some decent Claytonia and land cress, with some less good endive

Suitable for containers/shade?

These plants are fine for both shade and containers. Their shallow rooting system means that growth is excellent in any kind of box, tray or pot that is not too deep.

The trays I use for winter salad are 10 cm/4 in deep, filled with multipurpose potting or container compost, packed in firmly. Although these plants are not heavy feeders, they crop for several months. To save any need for feeding, it’s good to use compost with sufficient nutrients, such as potting compost.

I compared growth when using different composts, starting in October 2020 with winter salads in four trays, two of which contained commercial compost and two my own compost. Some rocket, mustard and coriander died in my own compost, I think from wet and soggy roots. This shows that when using your own compost in containers, it benefits from a drainage improver such as vermiculite or perlite, about 20%. I shall do that next time!

Salad plants in the photos below are not the only ones of this lesson, but they grow and harvest with the same timings.

Sow in September.
Transplant into boxes or the ground in October.
Harvest through winter, according to the ambient, under cover temperature which regulates growth.
Continue picking leaves until flowering initiates in early to mid-spring.

A windowsill planter with salad rocket, sown in September; I find it productive to space plants like this and pick leaf by leaf, rather than to cut across the top

These baby leaves have been sown thickly for cutting, 18 days earlier in mid-September

30th December – many salad plants can withstand a fair amount of frost; the leaves are frozen on these plants in boxes

Varieties

Claytonia and land cress have not been selected into named varieties. Corn salad is more important commercially and has been bred to produce varieties with attributes like colour and plant size.

Early April – this variegated land cress looks a lot nicer than it tastes, metallic and pungent

Orache is related to fathen – both can be used like spinach, and roach looks lovely in a salad mix; this was sown in February and is now under fleece on 5th April

22nd April – flowering Claytonia in the polytunnel, all edible and a beautiful addition to the salad bowl

Sow and propagate

You can sow direct or in trays.

Sowing direct is difficult when the soil is often dry and beds are full of vegetables still growing. Therefore raising plants in trays is worthwhile, also for reduced pest damage to seedlings.

Seeds germinate in about one week.

Sowing time

The absolute best time is early autumn, to avoid early flowering and disease, and for precious harvests in winter months. Below are my best sowing dates for growing outside here, to give you a reference. You can sow a week later, for growing through winter under cover.

Claytonia – mid-September.
Corn salad – 5th–15th September, a week earlier in Zone 7, for example.
Land cress – mid-August for autumn harvests outside, early September for winter cropping.

Sowing method

I suggest one plant per cell, for ease of harvest and larger leaves. Water trays to capacity before sowing.

Sow two or three seeds per cell, or a pinch of tiny Claytonia seeds (later you thin to the strongest).

Cover seeds with almost no compost, then water lightly.

For direct sowing, follow this method.

Often you need to run water along the bottom of a drill, before dropping in the seeds. In early autumn it’s common that the surface is dry.
Make drills 22 cm/9 in apart, even a little closer if it’s possible.
When direct-sown seedlings have two true leaves, thin to the spacings described below.

Sowing seeds in module cells in early September, to grow under cover for three to four weeks; they can then be transplanted

A module-raised watercress on the left and pot-grown land cress on the right; watercress trails and hugs the ground

I found a little space for summer sowing – directly seeding corn salad into pre-watered drills

Transplant, interplant

Transplant size and time

Growth slows by early October so these may be four weeks old before you transplant. Or, if the ground is ready, you can pop them in as small seedlings after two to three weeks. There is no absolute correct size.

Trays of land cress on the left and chervil on the right in mid-September, ready to transplant for winter leaves

Transplanting Claytonia into dibbed holes in October

Transplant method

It’s rapid to make holes with a wooden dibber, then pop in the small module seedlings. Plant a little deep but not too much so, especially for corn salad which has no long stem.

2nd October – the pretty Amorina lettuce has almost finished cropping; I intersowed with corn salad a month earlier

2nd October – interplants between old summer cos lettuce, now rising towards flowering after many harvests, and with new Claytonia

Spacing

Corn salad never grows large and can be as close as 10 cm/4 in. Claytonia and land cress grow larger, and 22 cm/9 in allows for many healthy green leaves which are easier to pick. The 22 cm/9 in spacing allows a longer root run, which helps plants to grow all winter for many pickings.

20 days later and I’ve taken plenty of harvests of chervil, pak choi, mustards and spinach

Interplant

There are many possibilities, as you see in the photos just below and dotted through this lesson. The principle is to find space between vegetables that will soon finish. During autumn this can mean a lot of possibilities, as long as the pattern of leaf growth on existing vegetables allows sufficient space for new leaves.

Suitable vegetables to transplant between are lettuce, Florence fennel, swede, winter radish and endive.

17th January in the Small Garden – top left is corn salad between the swede

Snow in the Small Garden eight days later – swede with corn salad interplanted three months earlier

Video

See how the outdoor salads are coming good after winter

Water

You almost never need to water any of these plants. However, do give water to transplants and if it’s dry in mid-autumn, it’s worth watering corn salad in particular.

These plants all root shallowly and do not tolerate the surface being dry, so they also benefit from a little water in early spring, if the soil is drying quickly.

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Harvest times and methods

How to judge readiness

Claytonia grows up and outward into a mound of leaves on quite long stems, including a few male flowers. Take a first cut before you see more than one or two male flowers, and before too many of the first leaves start to discolour with age.

Corn salad grows a tight and only medium-sized rosette of central leaves, which then stop growing larger because new growth is now on side shoots around the central rosette. First harvest is to cut the centre leaves, once you notice sideshoots developing. Cut low enough to secure the whole rosette of middle leaves, but not too low, so that at least a few sideshoots remain to continue growing.

Land cress also grows sideshoots, so look for outer leaves large enough to twist off before there are too many sideshoots.

You can use anything decomposed as the compost; these were transplanted in homemade compost on the left and old cow manure on the right – 16th October 2010

The same plantings one month later – 9th November

Early February – many harvests later, and still with homemade compost on the left and old cow manure on the right

31st March – despite no feeding of these plants, their growth is exuberant; here you see mizuna, endive, mustards, chard and Chinese cabbage

How to pick

Claytonia and corn salad need to be cut, while land cress can be cut or picked. Cut as low as you can without damaging the central and smallest leaves. Cutting low is good, to reduce the amount of yellowing stem in the way of subsequent harvests. Just be sure to cut higher than the smallest new leaves, otherwise regrowth may not happen!

13th February – Claytonia outside, showing brown leaves from cold damage; the nearest plants are struggling to regrow after a midwinter cut

Three weeks later and plants survived the snow and frost very well, although they are barely growing and have turned somewhat brown in the cold

12th November, and 52 days after transplanting – cut plants in front with one week of regrowth, and ready for a first cut at the back

Two different looks to show Claytonia just harvested and ready to harvest; on the previous cut, two weeks earlier, I had cut around the sides rather than across the top – this results in more rapid regrowth but the cutting takes longer

When to pick and how often

After cutting across plants, the next harvest will be after four to eight weeks, according to how cold winter is. With corn salad, the new harvest is small sideshoots, nobody’s favourite job in cold conditions, whereas the other two are fantastic for repeat cropping. By early spring, there is a much shorter time interval between harvests, which are larger.

Claytonia flowering outdoors on 2nd May – this is perfect for cutting to eat at this stage and looks amazing in mixed leaves

Claytonia at a slightly more advanced stage of flowering in late April; it’s close to getting to a seeding stage in the polytunnel

Storing

In the cool of winter, these leaves keep for at least a week, even outdoors, in the garage for example, and preferably in a polythene bag. It is more practical to harvest quite a few in one go, than to keep popping out in winter weather!

Saving seed

The period of cropping continues right up to the flowering stage, in mid-spring. Next, within four weeks, there are viable seeds on Claytonia, around six weeks for corn salad and up to ten weeks for land cress.

Gather flowering stems as soon as you notice some dry seeds on them, which means before too many seeds fall onto the ground. With land cress, twist out whole plants and hang to dry until midsummer.

Corn salad seeds fallen into the soil – 2nd June.

Winnowing seed in the breeze on 30th July – this blows away the light chaff and leaves cleaner seed in the bucket

Potential problems

Slugs and snails

They are prevalent in winter’s moisture, but less active in the cooler conditions. I often find slugs while harvesting leaves of these plants but do not see a lot of damage, because they are not slugs’ favourites.

These are ways to reduce slug numbers:

Adopt a no dig approach, which allows slug predators such as beetles to maintain or increase their numbers. Ground beetles (Carabidae) can eat a lot of slug eggs and baby slugs.
No dig results in soil with good aeration, compared to thin layers of damaged and compacted/anaerobic soil after digging. Fermentation can occur in anaerobic conditions and results in alcohol, which attracts slugs.
Remove and reduce nearby slug habitat.

Rabbits

You can protect susceptible plants using bird netting, However, in winter it’s more efficient to use mesh, for extra weather protection. In my garden, I have not known rabbits to dig under mesh or fleece, but others have experienced this.

Pigeon damage to outdoor land cress in late March

Pigeons

These will eat land cress, in cold winter weather above all. Bird netting is a good remedy – support it on hoops so it’s held more than 30 cm/12 in above plants.

Disease

The main one is mildew on corn salad, but only when it is sown too early and therefore growing in dry conditions in early autumn.

These plants are rustic, can grow in the wild and suffer very few problems.

The consequence of getting a sowing date wrong – mildew on these lambs lettuce, which were sown too early in August

And finally

Clear

Either cut the main stems at ground level, or twist out plants to leave most roots in the soil. It’s good to spread some compost in spring, between finishing the winter salads and transplanting summer vegetables.

A cover or mulch of 2.5 cm/1 in of compost will set your soil up nicely for cropping through the whole year.

Under cover, we add 4 cm/1.5 in, because of the intensity of cropping during every month of the year, with both summer and winter vegetables.

1st May in the polytunnel – we just cleared Red Frills mustard, then mulched for the year with compost of old cow manure, before summer plantings

Follow with

These plants are efficient at growing in space that would otherwise be unused in winter. Then they finish in spring, in time for any subsequent planting.

There are few implications related to rotation, and only land cress is related to commonly grown vegetables. You could still follow it with, say, cabbage, if that’s what you want to grow in that bed. It’s a free choice.

Cutting corn salad in early February is a slow job; for once, the cat is not in my way!

30th March – the same bed, and you can more easily see the strawberry plants I put in during late autumn, and the mulch of homemade compost

9th May – I have just twisted out the last corn salad, while the strawberries are now flowering

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For the fourth salad, see the endive guide.

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