A cloche is a transparent cover placed over plants to protect them from frost, wind, and pests. Types include glass bell cloches, plastic tunnel cloches, and fleece-covered hoops.

When should I use cloches?

Use cloches in early spring to warm soil before planting, in autumn to extend the harvest, and during cold snaps to protect tender seedlings.

What size cloches do I need?

Standard tunnel cloches are 60-100 cm long. For row crops (carrots, lettuce), 60cm wide cloches work well. For larger plants (courgettes), use wider barn-style cloches.

Do I need to ventilate under cloches?

Yes. On warm days, open the ends or lift the cloche slightly to prevent overheating and condensation. Plants can scorch under cloches in direct sun above 20°C.

Can I make DIY cloches?

Yes. Cut large plastic bottles in half for individual cloches. Bend wire hoops over a row and cover with polythene or fleece for tunnel cloches. Both are effective and free.

GardenCalcs

Cloche Calculator — How Many Cloches Do I Need

Work out cloche quantities and sizes to protect crops.

Row Length

Rows

Cloche Length

Standard tunnel cloches: 0.6-1m

How We Calculate This

Formula: Cloches per row = Row length / Cloche length (rounded up). Total = Cloches per row x Number of rows.

For example, 2 rows of 3m with 1m cloches needs 3 x 2 = 6 cloches.

Frequently Asked Questions

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Last updated: February 2026

All calculations are estimates based on standard gardening guidelines. Results may vary with soil conditions, climate, and plant varieties.