Whereas the waterside plants have developed from the original vegetation that flanked the River Cray before gravel working, the vegetation on the dry land is more haphazard in origin. It includes a number of an exotic species such as Canadian golden-rod around the marsh and Japanese knotweed on the drier banks. Buddleia also occurs here, its flowers attracted butterflies in summer.
Japanese knotweed is an aggressive alien spreading rapidly along the banks. At the Ruxley reserve, as along much of the River Cray, this plant is being destroyed to prevent it taking over.
The reserves banks show all stages in the natural succession from bare ground to wood. Annual weeds give way to herbaceous perennials like nettles and willow-herb; these are followed by bramble and woody shrubs like hawthorn, and finally trees such as birch and ash.
These mixtures of plants provide rich feeding grounds for both seed and insect eating birds. The latter are represented especially by summer warblers – garden warbler, blackcap, whitethroat, willow warbler and chiffchaff– as well as robins & wrens which are present all year. Amongst the seed-eating birds, linnets, goldfinches, greenfinches, chaffinches, bullfinches and redpolls all nest in the scrub.
