Chalky soil can make for difficult growing conditions for many hedging plants and shrubs as the topsoil layer may be particularly thin and prone to drought during the summer months. It is important to find out how deep the soil is above the chalk as it can affect the drainage and nutritional levels in the ground and it is pointless trying to change the conditions totally so it is best to adapt and grow plants accordingly.
To improve the situation, it may be helpful to bring in new topsoil if the layer of soil is very thin and perhaps by adding well-rotted garden compost or farmyard manure as well as the addition of mulch when planting you will be surprised at the results. Having said this, it is advisable not to dig the soil over too much as the good soil will just get buried with the chalk rising to the surface, and even after the aforementioned improvements have been made it may be wise to avoid ericaceous plants such as azaleas and rhododendrons as these like a more acidic soil and are unlikely to survive.
There are however many garden plants that will thrive in these conditions including the classic English hedges of Box and Yew as well as a whole range of our native trees and shrubs together with many other excellent hedging plants such as Beech, Holly, Lavender and Viburnum, Weigelas and Rosemary to name but a few. These are challenging conditions to plant in but with good ground preparation and research to identify the plants that will grow well a beautiful array of hedging, trees, ground cover and shrubs will be achieved.