Extending the Season with Fleece and Cloches
Fleece and cloches help gardeners sow earlier, protect crops from cold winds and carry harvests further into autumn. They work by trapping a little warmth and reducing weather stress, not by replacing sensible seasonal timing. Use them with ventilation, careful watering and crops suited to your local conditions.
Choose the right cover for the crop and space. Horticultural fleece is light, flexible and useful over rows of salads, brassicas, carrots and young seedlings. Clear cloches give more warmth and rain protection for individual plants or short rows, but need regular ventilation. A low tunnel made from hoops and fleece is often the most practical option for a raised bed or allotment row. Ensure material is clean and free from tears before use. Fine mesh is better than fleece where insect exclusion is the main aim, although it gives less warmth. Store covers dry between seasons to prevent mould and extend their useful life.
Prepare the soil before covering it. Weed thoroughly, add garden compost if needed and rake a level seedbed so covers sit evenly. For early sowings, cover the bed for a week before sowing to warm and dry the surface slightly. Sow hardy crops such as lettuce, rocket, spring onions, beetroot or broad beans according to packet guidance, then replace the cover immediately. Avoid forcing heat-loving crops outdoors too early, as courgettes, French beans and sweetcorn still need reliably warm conditions. In colder northern or Scottish gardens, wait longer or use a greenhouse and module trays to start tender plants before hardening them off.
Install fleece loosely so crops have room to grow. Lay it directly over sturdy seedlings or support it on hoops for taller, delicate or long-term crops. Bury or weight the edges continuously with boards, soil bags or pegs, because wind can lift a cover surprisingly easily. Leave enough extra material at the ends to seal them after watering or weeding. Check after every strong wind and replace damaged sections promptly. In a long row, overlap separate pieces by at least 20 cm and secure the overlap. Label what is beneath the cover, as it is easy to forget a direct sowing when the bed is hidden.
Ventilate cloches and tunnels whenever sunshine raises the temperature. Lift ends, open vents or remove covers briefly during mild days, then close them again before evening if frost is expected. Check soil moisture by pushing a finger beneath the cover: rain may run off the material, leaving plants drier than they appear. Water at the base during the morning, then allow foliage to dry before night. Do not leave a cloche closed over a crop during an unexpectedly warm afternoon, as seedlings can overheat and become leggy. Regular short checks are more effective than fitting a cover and ignoring it for weeks.
Use covers at both ends of the season. In spring, protect early salads, peas, beetroot and young brassicas from cold nights and drying winds. Remove fleece for a few hours on mild days if plants need hardening or if insect-pollinated crops are flowering. In autumn, cover salads, chard, parsley and other tolerant crops to slow weather damage and keep leaves cleaner. Harvest regularly, removing yellow leaves before they decay under the cover. Fleece can make a useful difference during short cold snaps, but severe weather may still end tender crops. Plan succession sowings rather than relying solely on protection to produce a longer harvest.
Combine covers with good crop management. Space plants generously enough for air to move when covers are lifted, and avoid using fleece over wet, diseased foliage. Rotate where you sow brassicas and remove old crop remains once harvesting finishes. If slugs are a recurring issue, inspect under covers in the morning and remove hiding places nearby. Keep a spare piece of fleece ready for sudden forecasts, especially around the last spring frost and early autumn cold nights. Record sowing and harvest dates under cover, then compare them with uncovered crops. This will show which techniques genuinely earn their space in your garden.
Frequently asked questions
When can I remove fleece in spring?
Remove it gradually once seedlings are growing strongly and nights are reliably mild for the crop. Check local conditions rather than relying on one date, especially in exposed or northern gardens. Harden plants by lifting the cover for longer periods before leaving it off completely.
Will fleece protect plants from all frost?
No. Fleece provides modest protection against light frost and cold wind, particularly when dry and well secured. It cannot guarantee survival during prolonged or severe freezing conditions. Add a second layer, cloche or greenhouse shelter for the most tender plants when necessary.
Do flowering crops need covers removed?
Usually yes, if insects need access to pollinate them. Lift fleece or open cloches during flowering on suitable days, then replace protection later if cold threatens. Self-pollinating crops may still benefit from ventilation, which helps prevent damp, stagnant conditions.
General guidance for UK home gardens and allotments. Conditions vary by region, soil and season; the RHS or a local garden centre can give site-specific advice. Page updated 19 Sep 2026.