The native trees that would appear in semi-wild areas in the West are hazel, holly, elder and hawthorn, and except for elder these are available. These could be underplanted with bluebells, wild garlic, wood sorrel, wood anemone and primroses, with ferns finding their own way in as spores. Ivy is a great ground cover too as is the woodrush.
Control weeds for the first few years to give the trees a chance to get established. Plant them as small ‘whips’ at about two metres apart each way but at random spacing, NOT in lines.
Go to our Plant finder for more choice of plants to resist strong exposure.