Your UK last frost date is the point in spring after which damaging frosts become unlikely, and it is the single most useful date to know before you plant anything tender outside. It varies a lot across the country, from around late April in the mild south and west to late May, or even into June, in the cold north and Scotland. The trouble is that it is an average, not a guarantee, so the sensible approach is to know the rough date for your area, watch the forecast as it approaches, and keep some fleece handy for late surprises. Get your timing right and you avoid the heartbreak of losing a whole tray of seedlings to one cold night.

I learned the value of this the hard way, more than once. In my early years on my Oxfordshire plot I planted out courgettes and beans in mid May because the weather felt warm and I was impatient, and watched a late frost blacken the lot overnight. These days I am far more patient, and I would rather plant a fortnight late than lose everything to one clear, cold night. Let me help you find your own frost date and, just as importantly, use it sensibly.

Find Your Last Frost Date by Postcode

Enter your postcode below for an estimated last frost window for your area. Treat it as a planning guide rather than a promise, since your own garden can differ from the regional average, and always check the actual forecast as your planting dates approach.

Why the Date Is Only Ever an Estimate

It is worth being honest about what a last frost date can and cannot tell you. It is a statistical average built from years of records, meaning that on a typical year frost is unlikely after that date, but nature does not read the statistics. Late frosts happen, some springs run cold, and one unusually clear, still night in an otherwise mild spell can still catch you out. This is why I never treat the date as a green light to plant everything at once and forget about it.

The right way to use it is as a planning anchor, not a rule. Use it to decide roughly when to start hardening off and planning your planting, then let the actual weather forecast make the final call in the days before you plant. A date on a chart and a clear sky tonight are two different things, and the sky wins every time.

Your Garden Has Its Own Microclimate

One thing the regional estimates cannot know is what your particular garden is like, and that can shift your real frost date by a couple of weeks either way. A sheltered town garden with walls that soak up heat, or one on a gentle south-facing slope, can be noticeably milder than the regional average. A garden that is high, exposed, or open to the north tends to be colder and later. Even within a single plot, conditions vary.

The one to really watch for is a frost pocket. Cold air is heavier than warm air and flows downhill, pooling in dips and against solid barriers like fences and hedges at the bottom of a slope. If part of your garden sits in a hollow, it can be several degrees colder than the rest on a still night, and it will frost when nowhere else does. If you know you have a frost pocket, keep the tender plants out of it and use the later end of your frost window.

Which Plants Actually Care

Not everything needs protecting, and knowing the difference saves a lot of worry. Hardy crops, the likes of broad beans, peas, onions, and most brassicas, shrug off frost and can go out well before your last frost date. It is the tender crops that are at risk, and losing them to frost is completely avoidable with a little patience. Courgettes, runner and French beans, tomatoes, pumpkins, sweetcorn, and cucumbers are all killed or badly checked by frost, and none of them should go outside unprotected until the risk has genuinely passed.

This is exactly why the last frost date matters so much for planning. It is the line that separates what you can plant early from what must wait. If you are itching to get going, focus on the hardy crops first and hold the tender ones back, which is much of the thinking behind what to plant in May, and check whether it is too late to plant vegetables later in the season if you miss a window. The full timing for each crop is in the vegetable planting calendar.

What Happens If You Plant Too Early

The obvious risk of planting tender crops too early is that a frost simply kills them, and that does happen. But there is a subtler cost too, one that catches people who get away with it. Even without a killing frost, cold soil and cold air check tender plants badly. They sit and sulk, grow slowly, and are so stressed that they often never fully recover, while a plant put out a fortnight later into warm soil races past them. Planting too early frequently gives you a worse crop, not an earlier one.

If you plant too late, by contrast, you lose a little of the season but the plants romp away in the warmth and often catch up completely. So when in doubt, wait. This ties straight into why plants grow slowly in cold conditions, and warming the soil is really a question of good soil improvement, and it is a big part of the wider picture of why vegetables fail. Patience genuinely pays here.

Protecting Crops When Frost Threatens

Even with careful timing, a late frost can be forecast just after you have planted out, and it is worth knowing how to protect things. Horticultural fleece is the gardener’s best friend here, thrown over vulnerable plants in the evening and taken off in the morning, and it can lift the temperature underneath by a few crucial degrees. A cloche, an upturned bucket, or even a sheet of cardboard will do the same job in a pinch. The key is to cover before dusk, so you trap the day’s warmth, rather than rushing out once the cold has already set in.

If frost catches your plants before you can act, do not give up on them too quickly. Some recover, especially if you can shade them from rapid morning thaw, and there is more on assessing and helping them in dealing with frost damage on plants and specifically protecting potato shoots, which are a common early casualty. The RHS guide to frost in the garden is worth a look for keeping an eye on the nights ahead.

A Simple Frost Plan for Every Year

After years of getting this wrong and then getting it right, my whole system boils down to a few habits. Find your rough last frost date and note it. Sow tender crops indoors or under cover in good time so they are ready to go out when the risk passes, not weeks before. Get hardy crops out early to make the most of the season. Then, as your frost date approaches, watch the forecast closely and keep fleece within reach for any late cold nights. Plant the tender crops out only once the ground has warmed and the forecast is clear.

None of this is complicated, and once it becomes habit you stop losing plants to frost almost entirely. The single most useful shift is simply to stop trusting the calendar and start trusting the soil and the sky. Warm soil and a mild forecast mean go. A clear cold night, whatever the date, means wait or cover. Do that, and frost stops being a gamble and becomes something you manage with ease.

UK Last Frost Dates: Frequently Asked Questions

A Sensible Place to Start

If you do just one thing with all this, find your rough last frost date from the checker above and note it in your diary. Then, as it approaches each spring, get into the habit of glancing at the forecast before you plant anything tender, and keep a length of fleece somewhere handy for the odd cold night that slips through.

Trust the soil and the sky over the calendar, be willing to wait a fortnight when a spring runs cold, and you will stop losing plants to frost almost entirely. It is one of those small pieces of timing that quietly separates a frustrating growing year from a smooth one. A little patience in May pays you back all summer.