What to plant in March in England: this is the month the outdoor season starts, and Sowstory's plan opens the bed for 15 crop profiles, from early carrots, radish, lettuce, spinach and peas to dwarf broad beans, parsnips, onion sets and first early potatoes. Indoors, the RHS lists tomatoes, sweet peppers, cucumbers, aubergines and celery under cover, while every tender crop stays inside until frost risk has passed in May or early June.
How early you can start depends on your soil and where you are. The RHS suggests March outdoor sowings in mild areas on light soil when conditions suit; on cold, wet or heavy ground, wait until April, when the soil has had longer to warm.
At a glance: what to plant in March
| Task | Crops | Source |
|---|---|---|
| Sow indoors or under cover | Tomatoes, sweet peppers, cucumbers, aubergines, celery, salads; nursery sowings of leeks, kale and summer brassicas | RHS, Sowstory |
| Sow outdoors | Carrots, radish, lettuce, spinach, chard, spring onions, peas, mangetout, dwarf broad beans, parsnips, kohlrabi, rocket | Sowstory, RHS (mild areas, light soil) |
| Plant out | Onion sets, first early potatoes; also shallot sets and asparagus crowns | Sowstory, RHS |
| Harvest | Standard kale, sprouting broccoli | Sowstory harvest windows |
For every month in one place, see the vegetable sowing calendar for England.
Sow indoors
The RHS March list for sowing under cover is sweet peppers, tomatoes, cucumbers, aubergines, celery, salads and globe artichokes. Sowstory's indoor windows for the outdoor versions of several of these open now:
- Outdoor cordon tomatoes: March to April indoors, for planting in June once nights stay warm (about 16°C). The RHS sows greenhouse tomatoes until mid-March and outdoor tomatoes from late March to early April; the seed needs about 18°C to germinate.
- Outdoor sweet peppers: late March to April indoors, planted out in June once nights stay above 12°C.
- Basil: March to May indoors, planted out in June once nights stay above 10°C.
- Self-blanching celery: March to April indoors at about 15°C, planted in May or June after hardening off.
- Brassicas and leeks for later: Sowstory's nursery or module windows for leeks, curly and standard kale, compact summer cabbage, calabrese and sprouting broccoli all run from March to May. They go into the bed from May (July for sprouting broccoli).
Outdoor ridge cucumbers can wait: Sowstory sows them indoors in late April.
Sow or plant outdoors
Seeds direct in the bed
These go straight into the bed from March in a Sowstory plan. On cold soil, cover early sowings with cloches or fleece, as the RHS suggests.
- Early carrots. Sow thinly; the RHS says thinning releases a scent that draws carrot fly. Sowstory checks for at least 30 cm of soil for early carrots.
- Radish, loose-leaf and head lettuce, spinach, chard and spring onions. The RHS sows lettuce and spring onions little and often, a short row every couple of weeks.
- Dwarf peas and mangetout. The RHS sows peas outdoors once the soil is about 10°C, and Sowstory's mangetout window has the same condition. Mice take newly sown seed.
- Dwarf broad beans. Sowstory's profile ('The Sutton') is sown direct in March or April only.
- Parsnips. Sowstory's window runs from March to May; germination is slow.
- Kohlrabi and salad rocket. Both can be sown direct from March.
Onion sets
Spring onion sets go in during March or April in a Sowstory plan. The RHS plants them 2 cm deep with the tip showing, 10–15 cm apart in rows 20–30 cm apart, and suggests netting or fleece until they root. Sowstory allows 25 cm between rows and 10 cm between sets, which fits about 72 sets in three rows along a 1.2 × 2.4 m bed as a simple estimate. More in how to grow onions.
First early potatoes
The RHS plants first earlies from late March and Gardeners' World from mid-March, a couple of weeks later in northern areas. The RHS plants them in a 15 cm deep trench, 30 cm apart. Sowstory plans them in March or April, with 30 cm between tubers and a 90 cm row corridor to leave room for earthing up: that is one row of about eight tubers along a 1.2 × 2.4 m bed. It checks for at least 30 cm of soil depth. See how to grow potatoes.
In a Sowstory plan this month
March is the first month that crops start in the bed in a Sowstory plan. These 15 profiles can begin now:
| Crop profile | Sowstory window |
|---|---|
| Carrot (early) | March–July |
| Radish | March–August |
| Loose-leaf lettuce | March–August |
| Head lettuce | March–August |
| Annual spinach | March–May, August–September |
| Chard | March–July |
| Spring onion | March–August |
| Onion sets | March–April |
| First early potato | March–April |
| Salad rocket | March–May or August |
| Dwarf pea | March–June, in a broad drill |
| Mangetout | March–June, once soil reaches about 10°C |
| Dwarf broad bean | March–April, no protected or autumn route |
| Parsnip | March–May |
| Kohlrabi | March–July |
Because so much can start at once, it helps to plan which rows go where and what follows them. Quick crops such as radish need the space for about eight weeks; first early potatoes for about 12; onion sets for about 24.
Sowstory lays out your bed to scale with these crops, tells you how many plants or rows fit and shows when each space comes free for the next sowing. It is coming soon to the App Store, and your first bed plan is free.
Sowstory's months are the same across England; they are not adjusted to your postcode, and the app does not give a frost date for your address.
Jobs this month
From the RHS March list:
- Chit potatoes before planting.
- Put up pea supports, and prepare runner bean trenches and supports for later.
- Cover early sowings with cloches or fleece.
- Protect seedlings from slugs.
- Plant asparagus crowns, Jerusalem artichokes and shallot sets alongside onion sets.
What not to sow yet
- Tender crops outside. Tomatoes, cucumbers, courgettes, French and runner beans and basil wait until frost risk has passed, which the RHS puts between the first half of May on the south coast and early June in north-east England. See the last frost in your area.
- Beetroot on cold soil. The RHS sows it once the soil is at least 7°C, from late March or April; Sowstory starts it in April.
- Second early and maincrop potatoes. Sowstory plants second earlies in April and maincrops from mid-April to early May.
- Outdoor sowings on heavy, wet ground. The RHS March list is for mild areas on light soil; elsewhere, wait for April.
Last month's list is in what to plant in February; next month, see what to plant in April.
Sources
- RHS: Grow your own, March jobs
- RHS: How to grow tomatoes
- RHS: How to grow onions
- RHS: How to grow potatoes
- RHS: How to grow peas
- RHS: How to grow beetroot
- RHS: How to grow carrots
- RHS: Carrot fly
- RHS: When to plant out tender plants
- BBC Gardeners' World: How to grow potatoes
- BBC Gardeners' World: How to grow onions
- Sowstory knowledge base, release v1.4