Frost decides two calendars at once: when you can plant, and when you can lay concrete, mortar and paving. Both move by weeks depending on where in Britain you stand — a Cornish garden runs a month ahead of a Highland one. Pick your region on the map to see your frost dates, then use the planting and landscaping guides below.
Tap your region on the map (or use the buttons). Dates are long-term averages — your own microclimate can shift them by a week or two either way.
Your zone
In the garden: Classic middle-England timing: tender plants out in early May, and don't trust a warm March — a late April snap catches Midlands gardeners most years.
On the building side: Stop mortaring once nights regularly dip below 3°C, typically from mid-November. Spring restarts reliably from late March.
The frost planting guide
Everything below keys off your zone's last spring frost. Your selected zone is Midlands, where the last frost typically falls late april – early may. Work backwards from that date.
| Plant group | Examples | When to plant |
|---|---|---|
| Very hardy vegetables | Broad beans, peas, onion sets, garlic, spinach | 4–6 weeks BEFORE your last frost |
| Hardy vegetables | Carrots, beetroot, lettuce, first early potatoes | 2–4 weeks BEFORE your last frost |
| Grass seed & lawn repair | New lawns, overseeding thin patches | When soil reaches 8–10°C — usually 2–4 weeks before last frost |
| Half-hardy (start indoors) | Courgettes, squash, sweetcorn, summer brassicas | Sow indoors 4 weeks before; plant out AT last frost |
| Tender plants | Tomatoes, runner & French beans, dahlias, summer bedding | 1–2 weeks AFTER your last frost |
| Frost-proof planting | Trees, hedging, hardy shrubs, spring bulbs | Autumn to early spring while dormant — but never into frozen ground |
"Start indoors" means a windowsill, greenhouse or cold frame. Whatever the group, harden plants off for a week before planting out — an hour or two outside on day one, building up to full days.
The last spring frost is the starting gun for tender planting — tomatoes, beans, bedding and dahlias all wait for it. The first autumn frost is the closing bell that ends their season. Between those two dates sits your whole tender growing year: roughly 280 days on the Cornish coast, barely 100 in a Highland glen. Sowing hardy veg and grass seed runs on soil temperature rather than frost dates — most seed wants a steady 8–10°C, which usually arrives two to four weeks before the last frost. Our grass seed rates guide covers the timing in detail.
Town and city gardens run a couple of degrees warmer than the countryside around them, gaining a week or two at each end of the season. South-facing walls store daytime heat and release it overnight — the best spot for anything borderline. And because cold air pools in dips, a garden at the foot of a slope can frost when the top stays clear. Treat your zone as the starting point, then adjust for your own plot.
Fleece or cloche anything tender, mulch around the crowns of borderline perennials, and move pots against the house wall. Water the soil in the afternoon before a cold night — moist soil holds more heat than dry. A single –1°C night burns tender leaves; the same plants under fleece sail through.
Cement gains strength through a chemical reaction with water — and below about 3°C that reaction nearly stops. Worse, if fresh work freezes within its first 24–48 hours, the water inside expands as ice and breaks the structure apart before it ever sets. The rule professionals use: don't lay mortar, concrete or screed at 3°C and falling, and protect fresh work overnight when frost is forecast. Our concrete calculator is ready whenever the weather is.
Water expands by about 9% as it freezes. Inside a mortar joint or a hairline crack, that expansion acts like a slow-motion crowbar — repeated freeze–thaw cycles blow the faces off bricks, crumble pointing and flake the surface off poorly cured concrete. Keeping water out is the defence: sound pointing, drainage that moves water away, and sealing or covering work that can't yet protect itself.
When waterlogged soil freezes, it lifts — and takes your slabs with it. Come the thaw, they settle unevenly and rock forever after. Patios and driveways resist heave with depth: a compacted free-draining MOT Type 1 sub-base (100mm for patios, 150mm for driveways) and full mortar beds, never dabs. Gravel driveways shrug frost off entirely — one reason they're so forgiving.
Frost only stops the wet trades. Digging out, laying sub-base, building raised beds, setting out, fencing in dry spells and all the planning and measuring are perfect winter jobs — do them now and the moment your zone's mortar season opens, you're laying, not digging.
It depends entirely on where you live: mid–late March on the South West coast, late March to mid-April in the South East and London, late April to early May across the Midlands and North, and as late as early June in Highland Scotland. Use the zone map above for your region — and remember these are averages, so keep an eye on the forecast each spring.