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Tips for harvesting vegetables
*The picking of salad leaves is as important as the growing of them*
Good picking results in more even harvests off longer living plants. Here I offer answers to some important questions such as how big does a plant need to grow before leaves can be picked off it, can odd leaves be picked at random, and is it best to harvest leaves or hearts.
First, a few things to consider.
- A growing medium that is rich in compost will grow many more leaves than poor soil: see other posts for increasing soil fertility, or if using containers fill pots with fresh compost -most organic multipurpose works well, perhaps with some well rotted manure or home made compost at the bottom
- At a certain stage of maturity, outer leaves start to decay by losing colour and being nibbled by slugs. All such leaves want picking off whilst harvesting, to keep slug numbers down and to make subsequent harvests easier
- The presence of many poor quality leaves at a plant’s base indicates either poor soil or over maturity, or both
- Plants grow larger in summer than in winter so leaves from October to March mature at a smaller size and are more fiddly to pick. Indoor leaves have much better quality at this time
- Salads have seasons, meaning that some salad plants are easier to grow in spring and summer (lettuce, spinach, pea shoots, dill), some are easier in autumn (mizuna, rocket, mustards, endive), and only a few thrive in winter (land cress, lambs lettuce, winter purslane)
Charles picking lettuce for the sixth week, Freckles on right has one more pick to offer as stems elongate
photos Andrea Duncan
PICKING is most productive, over a long period, when salad plants are all given about nine inches in diameter (22cm) of space to grow, and have filled at least half of that space before picking begins, so that a strong root system has developed.
- At this stage you can pick a few of the larger leaves from around the base of plants, at the same time as pulling off any decaying or eaten leaves - and removing any slugs you find! Always leave the small central leaves because they are plants’ ‘engines of growth’
- About a week later in summer, or twice that and more in winter, plants will have grown larger again and more leaves can be picked in the same way. This time there should be few if any decaying leaves so picking is quicker and easier.
- The number of pickings before plants rise to flower is variable, according to season, variety and sowing date. For example, lettuce sown in March can start yielding leaves in May and continue for ten weeks or more, while salad rocket sown in April will yield perhaps two harvests before flowering. Sow plants in season, grow them healthily, pick them carefully and you will be rewarded with leaves over long periods.
- Leaves from plants that are grown in healthy soil and compost, when rinsed and then kept cool and moist, will keep fresh and lively for several days after picking,so it is not necessary to harvest every day.
2 Other vegetables
The great thing about growing your own is the flexibility of being able to pick fresh vegetables, the downside is that sometimes vegetables need picking when you already have enough, peas and beans especially. Also, picking takes more time than people often realise.
Here is a brief guide to the harvesting needs of many common vegetables.
- Asparagus can be up to a foot (30cm) long and two thirds of that should be tender. In warm weather it is best picked every other day. Beetroot can be pulled at any size according to needs and likes, large ones have a bad reputation for woodiness but can be tender and tasty when grown in fertile soil.
- Beans mature quickly and need frequent picking, partly depending whether you want them small and tender or large and meatier. This applies to broad, french and runner beans, and they all go from tender to tough more quickly in hot weather.
- Brussels Sprouts are best picked when the adjoining leaf turns yellow and before too much yellow leaf is visible at their base. Blown or open ones are best picked small unless you want mini spring greens.
- Cabbage hearts can keep better once formed than if left on the plant where they may open to flower in summer or rot in frost in winter, except for savoys which survive most weather. Some spring cabbage never heart up, depending on variety partly, they just grow bigger.
- Calabrese, cauliflower and broccoli want picking before their mini flower buds elongate too much; it is a fine line between allowing them to reach full size and finding them ‘blown’ with tough stems, in hot weather especially.
- Carrots can be picked at any stage according to taste. A first picking of baby thinnings can help the remainder to swell up. Beyond a certain stage, some roots are at risk of rotting and splitting as they grow older, and carrot root fly too.
- Celeriac is best left in the soil until needed unless hard frost is expected, say -6C or below.
- Celery will carry on growing in moist, warm weather unless it is close together, when rotting may occur as well as the inevitable slug damage. Growth beyond maturity usually consists of side shoots which are like small supplementary heads.
- Chard stems can grow fat and with huge leaves - in good soil, warm, damp weather and with enough space. Otherwise pick them medium size when they are meeting the leaves of neighbouring plants, and keep plants tidy by removing any paler leaves that are losing quality, to reduce slugs and make the next picking easier.
- Courgettes need daily picking in hot weather, if you want them of small size, or pick less regularly if you like them longer and fatter. Leave alone for marrows.
- Cucumber can be picked thin and creamy or allowed to grow fatter with some seeds and a tougher, dark green skin. Picking them young allows new ones to develop more easily.
- Endive, like lettuce, can be picked leaf by leaf as described above, or allowed to heart up for one harvest with a knife. Hearts tend to rot beyond a certain point and are best cut when a fair proportion of their leaves are noticeably paler.
- Fennel (bulb)provokes the question, will it bulb or flower? Later sowings (june, July) in rich soil have a good chance of developing fat bulbs but any noticeable elongation invites the harvest before your bulb-to-be turns into a stem.
- Kohl Rabi are almost all best picked at golf ball size because tenderness turns woody soon after
- Onions for bulbs can be pulled when more or less swollen and eaten green, or left until their tops are inclining downwards, then pulled and left to dry or brought undercover. Spring sown or planted onions are best harvested before mid August in Britain if you want them dry for winter use. Spring onions can be pulled at any size according to taste.
- Parsnips’ flavour improves with cold weather so leave them until needed. Canker may develop in wet soil, less so where compost and no dig is adopted.
- Pea picking depends whether you want tender petit pois or more starchy peas - have fun experimenting.
- Peppers can be picked as soon as large enough for your needs, bigger ones have thicker walls; then waiting for colouring to red, yellow or whatever will take another two to four weeks depending on temperature.
- Potatoes stop growing when foliage turns yellow but can be harvested at any stage and are more tender when plants are still green.
- Pumpkin and squash are mature when their stalks wither and their skins harden, often with deep colour. Flavour is best if picked at this stage but if you run out of time in October, pick them immature before hard frost and bring them indoors, where they may finish ripening if already quite mature.
- Radish often go from tender to tough within a week so keep pulling and eating them!
- Rhubarb is best picked before its leaves discolour, a sign of hollow pithiness in the stems, and the first harvests in cool weather will be of small stems anyway so start early.
- Spinach growth depends so much on soil, variety and season: March and early April sowings may grow to large leaves and offer many pickings with more leaves developing, later sowings that mature in hot weather my flower before offering much harvest: once a central stem appears, pick anything good and pull up the plant.
- Swede and turnip grow a little even in winter, unless pigeons eat the leaves, and frost is not a problem so harvest as needed.
- Sweetcorn can be picked according to taste, over about two weeks the cobs go from pale yellow and tender to darker and more chewy. Watch initially for browning of the hairy tassels to indicate ripeness.
- Tomatoes are best picked when, or just before, fully coloured: beyond that and they risk splitting and turning soft. If there is blight on any leaves or stem, they will not keep for long.