Freezing is the simplest way to keep a glut. Beans, peas, sprouts and greens picked at their best and frozen the same day taste far closer to fresh than anything you can buy. The one step that makes the difference is blanching: a short dip in boiling water that stops the enzymes which otherwise turn frozen vegetables dull, tough and grassy within weeks.
This guide covers the method, a blanching chart for common garden crops, the vegetables you can freeze without blanching, and how long they keep. It completes our storage series, alongside guides on root vegetables, cabbage and Brussels sprouts.
- Pick young and freshly harvested; freeze the same day
- Blanch 1–5 minutes in boiling water, depending on the crop
- Cool in iced water for the same time, then dry well
- Keeps 8–12 months at −18 °C
Why blanch vegetables before freezing?
Vegetables keep working after they are picked. Natural enzymes continue to break down colour, flavour, texture and vitamins, and freezing only slows them down. A brief blanch in boiling water switches those enzymes off. It also brightens the colour, cleans the surface and softens leafy crops slightly so they pack more tightly. Unblanched beans and sprouts are fine for a few weeks, but after a couple of months they turn pale and develop off-flavours.
How to blanch and freeze, step by step
- Prepare the vegetables Wash, trim and cut into even pieces. Sort sprouts and florets by size so they blanch evenly.
- Bring a large pan to a rolling boil Use plenty of water: about 4 litres per 500 g of vegetables, so it returns to the boil quickly.
- Blanch in small batches Lower the vegetables in a basket or sieve and start timing as soon as the water boils again. Use the chart below.
- Cool in iced water Plunge straight into a bowl of water and ice for the same time as the blanch. This stops the cooking.
- Dry, open-freeze, then bag Drain and pat dry, spread on a tray and freeze for 1–2 hours, then tip into bags. The pieces stay separate, so you can take out a handful at a time.
Blanching times for garden vegetables
Times are from the moment the water returns to the boil.
- Peas (shelled): 1–2 minutes. Mangetout and sugar snaps: 1–2 minutes.
- French and runner beans: 2–3 minutes, whole or in pieces.
- Broad beans (shelled): 2–3 minutes.
- Brussels sprouts: 3 minutes for small, 4–5 minutes for large.
- Broccoli and cauliflower florets: 3 minutes.
- Kale, chard and spinach: 1–2 minutes; squeeze out the water before freezing.
- Carrots: 2–3 minutes sliced, 5 minutes for small whole carrots.
- Sweetcorn: 4 minutes on the cob, then cut off the kernels if you prefer.
Blanch or freeze raw?
Always blanch
Crops that lose colour and flavour quickly in the freezer.
- Beans, peas, broad beans and sweetcorn
- Brussels sprouts, broccoli, cauliflower, kale
- Carrots and other roots you want to keep for months
Freeze without blanching
Fine raw, especially for cooking later.
- Tomatoes, whole or chopped, for sauces and soups
- Peppers and chillies, sliced
- Herbs chopped into ice cube trays with water or oil
Can you freeze Brussels sprouts or beans without blanching? Yes, if you will use them within a month or two. For longer storage, blanching keeps them green and firm. Courgettes freeze best grated and squeezed, for soups and bakes, as whole slices turn watery when thawed.
Storing and using frozen vegetables
Label each bag with the crop and date, squeeze out as much air as you can, and keep the freezer at −18 °C or colder. Most blanched vegetables keep their quality for 8–12 months, which takes you comfortably to next year's harvest. Cook straight from frozen: they need only a few minutes because blanching has already part-cooked them. Our guide to harvesting and storing your produce covers which crops keep better in a shed or clamp instead.
Common mistakes
- Freezing old, tough vegetables. Freezing preserves quality; it does not improve it. Freeze young crops.
- Blanching too much at once. The water stops boiling and the vegetables stew.
- Skipping the ice bath. Vegetables keep cooking and turn soft.
- Freezing wet vegetables. Water turns to ice crystals and clumps everything together.
- No labels. Unlabelled bags become a mystery by spring.
Frequently asked questions
How long do frozen garden vegetables last?
Blanched vegetables keep good quality for 8–12 months at −18 °C. They remain safe after that, but texture and flavour decline.
Can I steam instead of boil to blanch?
Yes. Steam blanching takes about one and a half times as long as boiling, and keeps slightly more flavour in leafy crops.
Do I need to thaw frozen vegetables before cooking?
No. Add them straight to boiling water, a steamer or a pan; thawing first makes them soggy.
Which vegetables do not freeze well?
Lettuce, cucumber, radishes and other salad crops with a high water content go limp. Eat those fresh.
A well-stocked freezer is next summer's garden, saved for winter. Browse beans and peas, leafy brassicas and all vegetable seeds, see the full seed shop, or explore the rest of our growing guides.
