Crop timing

When to plant tomatoes outside in the UK

The short answer, on 27 October

Not this year. Outdoor tomatoes are finishing or finished. The next sowing is from late February (greenhouse) or late March (outdoor), with planting out in early summer. If your bed is now empty, see what can follow tomatoes.

Tomatoes are frost tender. The RHS moves them outside in early summer, once temperatures are reliably above 16°C, which in most of the UK is later than the first warm week of May.

The tomato year at a glance

From Vercro's crop catalogue. Planting out is shown as May to June; outside in the open, June is the safer half of that in most of the UK. Growing time in the catalogue counts from planting out, not sowing, so Vercro does not date a tomato harvest from the sowing day.

Tomato sowing, planting and harvest months
Window	J	F	M	A	M	J	J	A	S	O	N	D
sow indoorsFebruary to April	January: no	February: yes	March: yes	April: yes	May: no	June: no	July: no	August: no	September: no	October: no	November: no	December: no
plant outMay to June	January: no	February: no	March: no	April: no	May: yes	June: yes	July: no	August: no	September: no	October: no	November: no	December: no
harvestJuly to October	January: no	February: no	March: no	April: no	May: no	June: no	July: yes	August: yes	September: yes	October: yes	November: no	December: no

Growing time in the catalogue: 60 to 90 days from planting out, not from sowing. Family: Solanaceae.

Your dates

Add your postcode for your area's usual frost dates, and what they mean for tomato.

Want every crop at once, or a greenhouse? Open the full sowing tool.

How late frosts run across the UK

This replaces the regional frost table this page used to carry, which had no source. These are the average number of days of air frost in April, May and June over the last thirty years at Met Office stations. A coastal station in Cornwall averages none in May; an inland one in Somerset or the East Midlands averages close to one; the Cairngorms average several.

Average air frost days by month at Met Office stations
Station	Apr	May	Jun
Camborne87 m above sea level	0	0	0
Eastbourne7 m above sea level	0.2	0	0
Heathrow25 m above sea level	0.8	0	0
Yeovilton20 m above sea level	4.1	0.6	0
Sutton Bonington48 m above sea level	3.4	0.8	0
Durham102 m above sea level	3.3	0.8	0
Leuchars10 m above sea level	3.7	0.8	0
Braemar339 m above sea level	11.1	4.9	0.7

Average days of air frost per month, 1996 to 2025. Contains Met Office data © Crown copyright, Open Government Licence. A count of frosty days is not a last-frost date, and a garden can be colder or milder than the nearest station.

What changes the answer

Warmth, not only frost
The RHS test is temperatures reliably above 16°C, not simply "after the last frost". A frost-free but cold night still checks growth.
Greenhouse or outside
Greenhouse tomatoes are sown earlier, go in earlier and crop for longer into autumn. Outdoor tomatoes are sown later and planted out later.
Where you are
Coast and city stay milder than open inland ground and hills. See the frost table above, and your own area below.
This year, not the typical year
Your area’s typical last frost is a 50:50 date, and tomatoes need warm nights as well. Check the forecast for nights above 10°C before planting out (RHS).

Where the sources differ

Vercro's catalogue and published advice, side by side

Vercro's catalogue sows tomatoes indoors from February to April and plants out in May to June. The RHS splits sowing by where the plant will grow: late February to mid March for the greenhouse, late March to early April for outside. For outdoor plants, May is early by the RHS wording; its test is a temperature, not a month.

The catalogue also says tomatoes go out two weeks after the last frost. Vercro's frost dates for a place are averages, so adding two weeks to an average can still be too early. This page doesn't use that sum.

Common timing mistakes

Planting out on the first warm weekend
A warm spell in early May is often followed by cold nights. One frost will kill an unprotected tomato plant.
Skipping hardening off
Plants raised indoors are not used to wind, sun and cold nights. Moving them straight out sets them back for weeks.
Sowing too early for outside
A tomato sown in February for outdoors is leggy and pot-bound by the time it is safe to plant. Outdoor crops are sown later.
Greenhouse varieties outdoors
Some varieties need the extra warmth under glass and do poorly outside in a wet summer.

How to harden off tomatoes

Week 1

Move plants outside to a sheltered, partly shaded spot for two to three hours each afternoon, and bring them in before evening.

Week 2

Increase outdoor time to four to six hours, including some direct sun. Still bring them in on cold nights.

Final days

Leave them out all day and overnight if the forecast is mild. Then they are ready to plant.

Varieties often grown outside in the UK include Gardener's Delight, Tumbling Tom, Outdoor Girl, Sweet Million, Tigerella, Ferline. Ferline is sold as having some blight tolerance.

How Vercro handles this in a real garden

Vercro keeps each tomato planting against its bed or greenhouse, with the date it was sown or planted. Each morning Today uses your postcode's forecast and how far along each crop is to show the few jobs that matter, with a short reason.

When the plants come out in autumn, the bed's history keeps the potato and tomato family on record, so Vercro can say so if you later plan potatoes or tomatoes there.

Frequently asked questions

When can I plant tomatoes outside in the UK?

In early summer, once temperatures are reliably above 16°C (RHS). In practice that is usually late May in the mildest southern and coastal gardens and June further north and inland.

Can tomatoes go outside in April in the UK?

Not unprotected. Inland Met Office stations in England averaged up to four days of air frost in April between 1996 and 2025, and one frost will kill a tomato plant.

How do I harden off tomato plants?

Over a week or two, put them outside for a few hours a day in a sheltered spot, then longer and in more sun, bringing them in on cold nights, until they stay out overnight.

Keep going

Where this comes from

Crop windows, growing times and plant families come from Vercro's own curated crop catalogue, the same data the Vercro app uses. Where a published source says something different, we show both rather than choosing the convenient one. Reviewed 19 September 2026.

Tomatoes: grow your own, Royal Horticultural Society. Read 19 September 2026.
Historic station data (monthly air frost days, 1996 to 2025), Met Office, Open Government Licence v3.0. Read 19 September 2026.
Potato and tomato blight, Royal Horticultural Society. Read 19 September 2026.

Keep your tomatoes on the right bed

Add where your tomatoes are growing. Each morning Today shows the jobs that matter, from your local forecast and how far along each plant is.

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