Pelham Gardens
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Grow Guide

Greenhouse & Polytunnel

Growing Under Glass

A greenhouse or polytunnel extends your season by 6–8 weeks in both directions and opens up crops that simply do not perform reliably outdoors in the UK — tomatoes, cucumbers, chillies, peppers and more.

16 crops

Chives

Chives

herb · Easy

Mild onion flavour with delicate purple flowers. Cut back regularly for a continuous supply of fresh snipping leaves.

Lettuce

Lettuce

vegetable · Easy

Fast-growing and versatile. Sow every two weeks for a continuous harvest all season.

Mint

Mint

herb · Easy

Vigorous and fragrant. Grow in containers to keep it in check — harvest often for a continuous supply of fresh leaves.

Pak Choi

Pak Choi

vegetable · Easy

Fast-growing Asian greens with crisp stems and tender leaves. Ready in as little as 4–6 weeks from sowing. Perfect for spring and autumn gaps when other crops are slow.

Radish

Radish

vegetable · Easy

Ready in as little as four weeks. Perfect for filling gaps between slower crops.

Spring Onion

Spring Onion

vegetable · Easy

One of the fastest and most useful crops in the kitchen garden. Sow every few weeks and you'll have fresh spring onions continuously from spring to late autumn.

Swiss Chard

Swiss Chard

vegetable · Easy

Colourful, cut-and-come-again leaves with striking stems. One of the most reliable crops for a long harvest.

Basil

Basil

herb · Easy–Medium

Aromatic and tender. Grows best with warmth — plant alongside tomatoes for a classic combination.

Cucumber

Cucumber

vegetable · Easy–Medium

Crisp and refreshing. Cucumbers thrive with warmth and consistent moisture — excellent in a grow bag or greenhouse.

Parsley

Parsley

herb · Easy–Medium

Slow to start but worth the wait. Sow early indoors for a long, productive harvest from late spring through autumn.

Spinach

Spinach

vegetable · Easy–Medium

Fast-growing and nutrient-dense. Sow in spring and again in late summer to avoid the bolting season.

Strawberry

Strawberry

fruit · Easy–Medium

The most rewarding fruit to grow at home. Plant crowns in late summer or early spring for a bumper harvest the following June.

Tomato

Tomato

vegetable · Easy–Medium

Rich, sun-ripened fruits packed with flavour. Start indoors for a long and rewarding season.

Bell Pepper

Bell Pepper

vegetable · Medium

Slow-growing and rewarding. Start early, keep them warm, and by late summer you'll have glossy peppers that cost a fraction of supermarket prices. Far sweeter picked fresh and fully ripe.

Chilli

Chilli

vegetable · Medium

Heat-loving and endlessly rewarding. Start early indoors and they'll fruit abundantly from midsummer right through to first frost.

Okra

Okra

vegetable · Medium–Hard

A warm-climate crop that needs a long, hot season. In the UK it performs best in a greenhouse or polytunnel. Start early, keep it consistently warm, and you'll be rewarded with tender pods from midsummer right through to the first frost.

Grower's Notes

Expert Tips

01

Ventilate daily from May onwards

high temperatures and poor airflow are the main causes of disease under glass. Open vents and doors on warm mornings.

02

Water at the base of plants, not over the foliage.

Wet leaves in the enclosed environment of a greenhouse encourage botrytis and mildew.

03

Introduce biological controls (Phytoseiulus for spider mite, Encarsia for whitefly) at the first sign of pests — before populations build up.

04

Staging (benching) lets you use vertical space efficiently.

Grow salads and herbs at bench level below your tall tomato and cucumber plants.

05

In an unheated greenhouse, tomatoes can be sown and planted out 4–6 weeks earlier than outdoor plants. This alone makes a significant difference to total yield.

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