Soil, manure, composts 

Londonorganicsoil.co.uk - Affordable bulk buy in south London

Thompsons - Bulk buy for large quantities.

West Riding Organics - Bulk buy seed and cutting composts, plus potting compost.

Pots, trays, tools, irrigation etc

LBS Horticulture - Trade site for all trays, pots, planters, tools, canes, labels etc

Harrod Horticultural - Retail site for gardening tools, sundries and more.

Polytunnels

www.firsttunnels.co.uk - Great value tunnels and helpful advice for installing.

Seeds

Organic Garden Catalogue - Good selection, plus lots of other products.

Tamar organics - Organic seeds, great selection.

Franchi, Italian seeds - Generous packets,  interesting varieties.

Thomas Etty - Heritage varieties.

Stormy Hall - Open pollinated, biodynamic seeds.

Real Seeds - Open pollinated and organic seeds, good varieties including many unusual.

Nicky's Nursery - Good selection, many interesting herbs both culinary and medicinal.

Kings Seeds / Suffolk Herbs - Wide selection of vegetable and herb seeds. Discounts for groups.

Fruit Trees and bushes

Blackmoor Nursery - Great selection, bare root and container plants.

Edulis - Amazing selection of perennials, many unusual varieties suitable for permaculture gardens.

Keepers Nursery - Huge variety bare root fruit (available november - april).

Herb plants

Foxhollow Nurseries - Bulk buy a great variety of 9cm herb plants.