Harrod Horticultural

https://www.harrodhorticultural.com/garden-fleece-30gsm-pid7516.html?

Unlike many imitations our polyester yarn fleece has been manufactured with UV stabilisers for longer life - so won't disintegrate or tear - yet soft and light enough to be placed directly over plants. Can also be used to help to warm up the soil to achieve earlier harvesting of healthy crops.

This quality horticultural fleece is available in 2m & 4m widths and comes in great value Saver Packs.

Haxnicks

https://www.haxnicks.co.uk/garden-products/plant-protection-fabrics-hoops

Haxnicks helps you to produce earlier crops, protect from frost damage, avoid wind damage and prevent sun scorching. We can help keep those pesky invaders at bay with bird, animal and insect protection. 

So whether it’s the weather or the weevil that’s out to get your garden you will find a way to fight it here.

Dejex

https://www.dejex.co.uk/field-scale-polythene-fleece/c-45.html

Our UK manufactured frost protection fleece fabric has been tested over the years in the toughest of climates. 

Due to its unique construction the fabric regulates temperature both day and night, giving the crop added protection by creating a micro climate under the fabric itself, promoting the growth of the crop as well as offering frost protection.

The Garden Superstore

https://www.thegardensuperstore.co.uk/plant-protection/netting-and-fabrics/fleece

Garden fleece protects your crops not only in the colder months from frost and snow, but also use it as a barrier to keep pests at bay during the growing months.

You can buy it by the meter.

Quickcrop

https://www.quickcrop.co.uk/category/fleece-and-mesh-rolls

The Quickcrop Horticultural Fleece is available in a range of sizes including bulk rolls. They are made from very light weight material which will insulate seedlings from temperatures down to -3 or -4 degrees.

This agricultural fleece is the best garden cover to use in the cold weather and offers ideal frost protection for young plants and seedlings.

Two Wests & Elliot

https://www.twowests.co.uk/cosygrow-fleece

Cosygrow is a lightweight fleece used to protect plants from adverse weather conditions and damage from insects and birds etc. Allows plants to remain naturally watered & ventilated but at the same time increases soil temperatures & humidity levels.
Washable, tear-resistant & ultra-violet light stabilised it will last for several seasons.

DT Brown

https://www.dtbrownseeds.co.uk/Garden-Essentials-1/Netting-and-Protection/Fleece-UV30.html

Fleece UV30 provides perfect protection from frost, wind, hail, insects and other pests, plus diffuses strong sunlight and reduces transpiration. 

DT Brown's UV fleece is 30g/sq.m giving better insulation than most other fleeces. With our fleece, you can protect down to -5/6 degrees C.
Order from 2 metres upwards in metre-full lengths (width of 3.2m).