Sowing Timeline for Vegetables
These dates are distilled from 38 years trial and error in my gardens, where my results have highlighted best timings for best results.
You can sow these vegetables at different times and they will grow, but the outcomes will be different, such as lower yield, more pest and disease, perhaps a tendency to flower rather than leaf. Hence for example I do not recommend sowing salad rocket and mizuna in the spring because it’s their flowering season, although many gardeners do and are happy with the smaller yield and insect-damaged leaves, compared with healthier leaves and more weeks, even months of picking, from August sowings.
Dates are based on the climate of Somerset in south west UK, USDA zone 8-9, last frost mid May and first frost mid October. They refer to sowing seeds, not planting plants.
Sowing and planting
These two words are often used interchangeably, which causes confusion. On this page at least, sow refers to seeds, from celery to tomato to garlic, even potato. Plant refers to setting out a plant with leaves.
- How big your plant is when you set it in the ground is your call.
- I recommend planting small ones of average 4 weeks since sowing, except for tomatoes, aubergines etc.
- Always plant before the roots have used all available compost and before you see leaves going yellow or purple (lack of nitrogen mostly).
- Older plants take more time to establish so you lose cropping time in the end.
- Use fleece/row covers in spring to help young plants establish.
- Fleece reduces light by 15-30% but in spring this does not matter, because there is a surplus of light, and fleece converts some of the surplus to otherwise-absent warmth. Result: net gain.
Undercover and outside/outdoors
Seeds require more warmth to germinate than plants need to grow. I recommend sowing “undercover” where it’s warmer: windowsill, electric propagator, greenhouse, anywhere warm.
After about two weeks as new leaves grow fast, most plants need full light as much as or more than warmth. So look to move them from windowsill to greenhouse/polytunnel/cold frame.
All sowings I recommend in February and early March, until tomatoes, are frost tolerant. So they will survive frost in a greenhouse say, as seedlings.
I put with warmth for seedlings/plants that are killed by frost AND need extra warmth to grow.
- Planting “outdoors” means setting plants in the ground, as opposed to sowing seeds in a greenhouse or polytunnel. This page is about sowing and does not have planting dates – see my Diary for more on that.
A note on applying these dates in different climatic zones
We need to differentiate between cold tolerant vegetables/herbs with frost resistance, and warmth loving ones.
1 Plants which grow in the cold, and are not killed by frosts of say -6C/low twenties F, include peas, onions, lettuce, spinach, brassicas and coriander. 2 Plantings which are killed by frost include tomatoes and sweetcorn.
3 Vegetables which positively require heat to grow, include runner/pole and French/bush beans, aubergines/eggplants and cucumbers.
I would sow the cold tolerant vegetables and herbs maybe a week earlier or at the same time in a warmer climate than here, and the latter two categories about two weeks earlier, if say last frost date is in April rather than (Homeacres) mid May. That is in spring.
In late summer and autumn generally, make sowings a week or two later in say zone 9 and where summers are hotter than here – our average summer day is 21C/70F, we are oceanic-temperate.
From these guidelines, you can work out best dates through keeping notes and observing.
The common advice of “sow every two weeks” applies only if you want lettuce hearts. For loose leaves, 4-5 sowings in the whole year* suffice, when you use my method of never cutting lettuce plants, but picking outer leaves every few days. This allows a long life to each plant, see my lettuce love video for more details.
*sow undercover Feb-Mar, then 1st June, mid July (these three sowings for growing outdoors), and early September for undercover lettuce in winter.
Best start date is after Valentines Day when light is increasing at last, and fast.
Sow undercover broad beans, spinach, lettuce, peas for shoots, onion, salad onion, early brassicas (cabbage, calabrese, kohlrabi, cauliflower, turnips), radish, bulb fennel, parsley, coriander, dill. With warmth aubergine, pepper, chilli – sow these by early March
Sow outside broad beans, garlic if not already
Sow undercover as for February plus peas, Boltardy beetroot, celery & celeriac mid month. With warmth tomatoes – sow before mid month for undercover cropping, melon at month’s end
Sow outside broad beans, garlic if not already, and after mid month sow lettuce, spinach, peas, onion, salad onion, early brassicas, parsley, coriander, dill, parsnips, first early potato late March.
Sow undercover as for March (except its getting late for celeriac, sow asap), leeks, leaf beet, beetroot (all varieties), chard at month’s end, tomatoes for outdoor growing. With warmth and around mid month, cucumber, courgette, squash, sweetcorn
Sow outside all potatoes, broad beans, lettuce, spinach, peas, salad onion, early and autumn brassicas, parsley, leeks, leaf beet, carrots
- Update 2020 about flea beetles: these pests have in the last year become more severe, in much of the UK at least. I advise to sow all brassica under cover, where possible, because they eat less there, And at Homeacres I do not sow radish from end March to mid August, because flea beetles do such damage to their tender leaves.
Sow undercover Courgette, French and climbing beans, leaf beet, beetroot, chard, lettuce, winter brassicas, salad onion. Plus leeks and winter squash by early May.
Swede at end May
Sow outside same as undercover, also maincrop potatoes in early May, carrots, parsnips but keep seedbed moist until germinated.
Sow undercover beetroot, swede, lettuce, leaf beet, chard, kale, purple sprouting broccoli, cauliflower for both autumn & spring, calabrese for autumn harvests.
After solstice sow endive, chicory, kohlrabi and Florence fennel.
Sow outside same as undercover, also carrots.
Sow undercover Kohlrabi, lettuce, leaf beet, chard, endive, chicory, Florence fennel, chervil, coriander. Plus beetroot and savoy cabbage in first week.
After mid month, land cress, wild rocket, Chinese cabbage and spinach.
At month’s end, mustards, pak choi, salad rocket, turnips – though first week August is often better.
Sow outside same as undercover, and carrots until mid July.
Sow undercover endive and Florence fennel until 10th, lettuce (late August sowings to overwinter as small plants), claytonia, oriental leaves, salad rocket, turnips multisown and true spinach.
August is fantastic for sowing salad rocket, oriental leaves and spinach. Sow by mid month in order to have vigorous harvests through autumn, sow late month for smaller plants in autumn that may overwinter more strongly.
- chervil – coriander – dill – land cress – wild rocket -spinach by mid August for autumn cropping,
- any salads in mid August for planting September and to grow under a cloche,
- spinach – spring onion – spring cabbage late August for overwintering small.
Sow outside same as undercover but approximately a week earlier
- For outdoor planting to crop in autumn/winter lambs lettuce, mizuna, salad rocket,
- For outdoor planting to overwinter small, in early September sow lettuce, spinach, chervil, coriander, dill.
- For undercover planting sow in early to mid September all salads (includes spinach, chard mustards, kale etc which you can grow large for cooking), spring onion.
Sow outside same as undercover but a week earlier, last salad sowings by 10th September.
Outside sow garlic. You can also sow onion sets though I recommend caution with these as they risk harbouring mildew over winter which infects onions in May and thus reduces growth/storage potential of spring-sown onions. Spring onions sown in August, White Lisbon type, seem less prone to this.
Depending where you live, from early November its worth sowing broad beans to overwinter as small plants, such as Aquadulce Claudia and Monica; sowing in December is possible too, both undercover (unheated) and outside, likewise for garlic.