How to Grow Tomatillo in the UK

Tomatillo is the secret to proper Mexican salsa verde, and it grows really well in a UK greenhouse. The tangy, zesty fruits grow inside papery husks on big, bushy plants about 1-1.5m tall. They’re in the same family as tomatoes and peppers, but there’s one thing that catches out lots of first-timers: you must grow at least two.

They’re related to the cape gooseberry, but the fruits are bigger, savoury rather than sweet, and made for cooking. If you’ve raised tomatoes in the UK before, you’ll find tomatillos very familiar.

Why you need two or more tomatillo plants

One tomatillo on its own won’t make fruit. It’ll flower happily, but it can’t pollinate itself. You need at least two plants, growing within about 1m of each other.

Plants from the same packet are fine, as each seed grows into a slightly different plant. You don’t need to buy two varieties, though mixing them is fine too.

Give pollination a hand by gently shaking the plants when they’re in flower, or dabbing between flowers with a soft paintbrush. Outdoors, bees do the job. In a greenhouse, open the doors and vents so insects can get in, or do it yourself.

Tomatillos can’t pollinate themselves, so grow at least two within about a metre. Open the doors so insects can reach the flowers.

When to sow tomatillo seeds

Sow indoors in March, about 8-10 weeks before your last frost. Like peppers, they need a long season, and late sowings may not ripen before autumn.

Sowing: Fill 7cm pots with peat-free seed compost. Sow two seeds per pot, 5mm deep, and water from below. Keep them in a heated propagator at about 20-22°C. Seedlings usually appear within a couple of weeks. Snip out the weaker one.

Growing on: Once seedlings have two true leaves, move them into 1-litre pots. Keep them warm and bright and give a balanced liquid feed every fortnight. They grow faster than tomatoes, so pot them on promptly.

Hardening off: Start hardening off in mid to late May. Put them out by day and bring them in at night for 10-14 days. Plant out once frosts are over: late May in the south, early June further north.

For more on starting seeds indoors, see our seed sowing guide.

Tomatillo seedlings ready for bigger pots, about 4 weeks after sowing.

Greenhouse vs outdoor growing in the UK

A greenhouse or polytunnel gives the most reliable crop. The extra warmth speeds up ripening and gives you a longer picking season.

In a greenhouse: Plant in the border soil or in 25-litre pots, 60cm apart. Tomatillos grow as wide as they are tall, so give them room. Tie them to a central stake and take off the lowest side shoots to keep them open. They hate stuffy, damp air, so open the doors and vents on warm days.

Outdoors: Pick your warmest, most sheltered spot, ideally by a south-facing wall. Plant 60-80cm apart with a sturdy stake. Expect a smaller crop that ripens later. Cover with fleece in September to protect from early frosts.

Polytunnel: A great middle ground. It’s warm like a greenhouse and usually airier, and crops well.

Outdoors, your warmest wall makes all the difference. Expect a later, smaller crop than under glass.

Best tomatillo varieties for the UK

Toma Verde is the one to start with. It has big green fruits that ripen fairly quickly, sets fruit well in cooler summers and is easy to find from UK seed companies. This is the classic salsa verde tomatillo.

Purple tomatillo has slightly smaller fruits that turn deep purple when ripe. They’re sweeter and less sharp than green ones. They need more warmth to ripen, so grow them under cover. They look stunning on the plate.

Grande Rio has extra-large fruits that are great for cooking. It needs a long, warm season, so it’s best in a greenhouse. The plants are big and sprawling.

De Milpa is a heritage variety with small, very tasty sweet-sharp fruits, and lots of them. Lovely for salsa and eating raw.

Green varieties are tangy and best for salsa verde. Purple ones are sweeter and need more warmth to ripen.

Planting and caring for tomatillos

Soil: Tomatillos are less fussy than tomatoes. Any fertile soil that drains well will do. Dig in a bucketful of garden compost per plant, and add grit on heavy clay. In pots, use multipurpose compost in containers of at least 25 litres.

Staking: Push in a 1.5m stake when you plant, and tie the stem to it every 30cm as it grows. Heavy crops make the plants top-heavy, and branches can snap or fruit can rot on the ground. A tomato cage works too.

Watering: Water regularly but don’t let them get waterlogged. They cope with dry spells better than tomatoes once settled. In a greenhouse, water every 2-3 days. Outside, water in dry spells. Uneven watering can make the fruit split inside the husk.

Feeding: Once the first flowers open, give a high-potash tomato feed every 10-14 days. Avoid high-nitrogen feeds, which give lots of leaves and fewer fruits.

Pruning: Take off side shoots up to about 30cm from the ground to let air in. Above that, let the plant branch naturally. Don’t prune as hard as tomatoes, as tomatillos fruit on their side branches. Pick off yellowing leaves.

Staked tomatillo plants in a greenhouse, with fruits swelling inside their papery husks.

When and how to harvest tomatillos

Pick when the fruit fills the husk and the husk starts to dry and split. The fruit should feel firm and pop out of the husk easily.

Green varieties: pick them green, once they’re full size and the husk is splitting. Don’t wait for a colour change. Overripe ones turn yellow and lose their tang.

Purple varieties: let them turn fully purple before picking. They’re sweetest when properly ripe.

How often: check every few days from August. Fruits ripen over several weeks, and regular picking keeps more coming.

Storing: take the husks off and rinse away the sticky coating. Whole tomatillos keep for a couple of weeks in the fridge. For longer, roast and freeze them as a purée.

End of the season: before the first frost, pick everything that’s left. Small, unripe ones are sharp but still fine in a green salsa.

Pick green types once the fruit fills the husk and it starts to split. Don’t wait for a colour change, or they lose their tang.

What to cook with tomatillos

Salsa verde is the reason to grow them. Grill 500g of husked tomatillos for about 8-10 minutes until charred and soft. Blend with a handful of coriander, half a white onion, a green chilli (or to taste), the juice of a lime and some salt. Serve with tacos, grilled chicken or eggs, or as a dip with tortilla chips.

Green enchilada sauce: make double the salsa verde, thin with 200ml of stock and simmer for 15 minutes. Pour over filled tortillas, top with cheese and bake at 180°C for 20 minutes.

Freezing: roast, blend to a purée and freeze in ice cube trays. Each cube is a little burst of salsa verde for winter. They make a good chutney too, with green chilli, ginger and sugar.

For more Mexican-style crops, see our guides to growing sweet peppers and when to plant tomatoes.

Pests and problems

Tomatillos get the same pests as tomatoes, but they’re usually tougher.

Aphids: greenfly and blackfly gather on shoot tips in early summer. Squash them, wash them off with a jet of water, or let ladybirds and other predators help. The damage is usually only cosmetic.

Whitefly: a common greenhouse pest. Hang yellow sticky traps, and try the tiny parasitic wasp Encarsia formosa as a biological control. Good ventilation helps, as whitefly love hot, still air.

Blight: tomatillos can catch late blight, the same disease that hits tomatoes and potatoes. Growing under cover cuts the risk. Outdoors, water the soil not the leaves, and remove affected leaves straight away.

No fruit: nearly always because there’s only one plant, or no insects can get into a closed greenhouse. Grow at least two, shake the stems or use a paintbrush, and open the vents.

Blossom end rot: sometimes shows on the first fruits as a brown patch on the bottom. Keep the soil evenly moist and mulch around the plants.

Husks splitting open: the sign that tomatillos are ready to pick.

For more ideas to fill your greenhouse, see our guide to the best greenhouse plants month by month. The RHS Physalis growing guide covers the wider family, including cape gooseberries.

Frequently asked questions

Why is my tomatillo plant flowering but not fruiting?

Most likely because you only have one plant. Tomatillos can’t pollinate themselves, so you need at least two, and three is even better. Plant them within 1m of each other. Plants from the same seed packet are fine, as each seed is different. Give the plants a gentle shake when they’re in flower to help the pollen move.

Can I grow tomatillos outdoors in the UK?

Yes, in a warm, sheltered spot, mostly in the south. Outdoor plants usually crop less and later than ones under cover. Further north, a greenhouse or polytunnel is a much safer bet. Stake outdoor plants and cover them with fleece in September to stretch the season.

When are tomatillos ready to harvest?

When the fruit fills the husk and the husk starts to split. The husk dries and goes papery, and the fruit inside feels firm. Green varieties like Toma Verde are picked while still bright green. Purple ones get darker as they ripen. Don’t wait for them to go soft.

What is the difference between tomatillos and cape gooseberries?

They’re relatives, but very different fruits. Tomatillos are bigger, tangy and savoury, and used in Mexican cooking. Cape gooseberries are small, sweet and eaten as a fruit. Tomatillos need two plants to set fruit, while cape gooseberries manage on their own. Both grow well in a UK greenhouse.

Can I save tomatillo seeds?

Yes, it’s easy. Cut a ripe fruit in half, scoop the seeds into a sieve and rinse off the sticky gel. Dry them on kitchen paper for a week somewhere cool and airy, then store them in a labelled envelope. If you grew more than one variety, they may cross, so the seedlings might not match the parent.

Do tomatillos need staking?

Yes, they get big and sprawly. Plants grow 1-1.5m tall, and branches flop to the ground under the weight of fruit. Use a sturdy stake with ties every 30cm, or a tomato cage. Taking off the lowest side shoots keeps the plant open and airy.

What do I do with tomatillos?

Make salsa verde, the classic Mexican green sauce. Roast or boil them, then blend with coriander, onion, chilli and lime juice. They’re also great in green enchilada sauce, stirred into stews or sliced into salads. Freeze extra as a roasted purée in ice cube trays.