‘Look after your soil and it will look after your plants’ is the most important advice that I pass onto clients.  Plants and trees will thrive on a soil with good structure, air, moisture, organic and mycorrhizal fungi content.  Knowing your soil type is key to ensuring you treat it with appropriate care – whether it is sticky clay or the sandy soil I have.  At a soil conference I attended  last week organised by  Tim O’Hare Associates,  soil compaction was a key topic – if a soil is compacted the trees/plants cannot access water, nutrients and air and can soon keel over and die.   Garden designers are often called in to design clients’ gardens after major building works and the state of the soil can be lifeless and anaerobic – this happened to me recently in a London garden.  I admit to feeling relieved when sitting in the conference that we had taken  the correct and appropriate measures to ensure the health of the soil and the roots of the existing trees by de-compacting the soil with an air spade, improving the soil structure by incorporating plenty of organic matter, applying mycorrhizal fungi to the roots of the new plants then adding a layer of mulch.   The plants are in and looking happy and healthy.