Preparing trees, shrubs and perennials for autumn
Bare root trees and shrubs will become available later in the season so now, while the soil is relatively warm, is the time to prepare the ground if you’re planning to plant a new tree or hedge. Dig over the entire area removing any weed roots and dig in plenty of organic matter. It is hard work but the new plants will reward you for all the effort next year!
Move trees and shrubs while there is still time to move things around in the garden as the soil is relatively warm. At this time of year, there will be less need to water plants that have been moved as there would be in hot weather.
Cut back herbaceous perennials (plants that die back in the winter and re-appear in the spring) that have finished flowering. This make the garden look tidier and discourages diseases attacking old growth. If on some plants the flowers have finished, but the foliage is still green and attractive, leave it until it is really blackened by frosts. Cutting everything down can leave unsightly gaps in the borders and should be avoided until as late in the autumn as possible. Any soft growth that has been cut down, such as geraniums for example, can be consigned to the compost heap or ‘green bin’ if you have a collection in your area.
Lift and divide established perennial plants. These are the plants which are not trees, shrubs or bulbs – they tend to make up the flower garden. The name basically means plants that survive for many years. Dividing perennials regularly will ensure healthy, vigorous plants that will continue to perform year after year. It also offers the opportunity to multiply your plants. If you’re not sure, older clumps are easily spotted, as all the young, vigorous growth is towards the outside of the clump and the centre is bare. Dividing can be done from now until spring, so long as soil conditions allow. My rule of thumb is if the soil is so wet it sticks to your boots, keep off it. Late flowering perennials like Asters (Michaelmas Daisies) are best left until spring before being divided. Lift plants gently with a garden fork, working outwards from the crown’s centre to limit root damage. Shake off excess soil so that roots are clearly visible. Divide by pulling apart by hand or by separating with a garden fork or spade.