Shoot Gardening is a great resource for identifying a wide range of plants, getting advice on looking after them and putting together lists of plants you already have or plants you would like

A charity campaigning for growing organically. Lots of useful incormation and advice.

A great seed company offering lots of unusual seeds to grow your own flowers, fruit, vegetbles and lots more.

A high quality web site selling plants, tools, seeds, pots etc with well-written plant descriptions and high quality photography. 

A great local family business selling plants, compost, tools including delivery. Based in Wood Street E17. 

Waltham Forest's horticultural hub, promoting and supporting community gardening activities in the borough

A national charity promoting the benefits of trees and woodlands. Lots of practical advice on tree selection and planting on the website.