The gardening jobs to do in September – from bulb planting to honey fungus checks

Rains have returned to most regions now, with some further along in re-wetting than others. This is a great relief, of course, as time is pressing to get the garden ready for winter and next year, and moist, softened soil is helpful. Rain re-wets the soil stage by stage with the water moving down the soil with each rainy day, wetting a little bit deeper until the soil is fully soaked. With soil so dry after summer, this may well take two or more months, so don’t be surprised to find dry, dusty soil deeper down when planting bulbs and harvesting root vegetables. If the soil is still dry at depth when planting trees or shrubs, fill the planting hole with water twice before planting. Water butts should be full enough by then to avoid having to use tap water in areas that may still be in drought. Shorts The soil is very warm and plants will have time to grow new roots for spring. Deciduous trees and shrubs are best planted after leaf-fall or thereabouts, which means October. Evergreen shrubs, however, are best planted now, once the ground is moist and soft enough. Vegetable crops have started to regrow after a long period of near-dormant growth for some crops, including the cabbage tribe or brassicas and leeks. It is too late to feed them, but the breakdown of soil organic matter over the summer will have released nutrients that plants can now take up. Light falls away fast now, but with their big green leaves, these crops can harvest sunlight efficiently and will bulk up for winter and spring crops. It is worth buying or begging some spring cabbage plants to plant now, as these will be ready to cut in spring when other vegetables are scarce. Runner beans in particular relish cooler, moister weather and, like courgettes, will keep cropping for weeks, yet if the fruits or pods are harvested frequently so that no mature ones form, this will suppress cropping. Dahlias and fuchsias also do well when the nights cool and the days remain warm. Keeping up with deadheading will prolong their displays until the autumn frosts arrive. Apples have matured earlier than usual, so be ready to gather these as soon as they begin to fall from the tree. Dahlias do well when the nights start to get colder (Photo: RHS/Nicola Stocken) Some droughted deciduous trees and shrubs lack leaves. It is unlikely that more will grow at this late season and anyway, plants are getting ready to shed leaves. Most will probably recover in spring, but there will almost certainly be casualties. It won’t be clear if a tree really is dead until May or June when the shoots will show no green beneath bark scraped with a fingernail or penknife blade. Check ailing trees now, though, for honey fungus, which rots plant tissue at about ground level. It is the final straw for some drought-stressed plants. When honey fungus is found, it is best to remove the tree along with all roots and replant this time next year when the disease will have died out. Look for white fungal material with a mushroom-like smell under the bark at about ground level on the trunk and nearby roots. The underlying wood is soft and easily penetrated with a penknife blade. The characteristic honey-coloured mushrooms usually appear from now until November. Bulb planting is much easier now that the soil has begun to soften. Plant these as soon as you can so they make good roots. Hyacinths and tulips can be planted as late as November, but other bulbs definitely like earlier planting.