A distinct lowering of temperatures and the first of the autumn rains signal a change of season. While March may give us an Indian summer, the full heat of the sun has almost certainly gone until next year now. This means you can start planting again.
Lift and divide grasses and many perennials (most of the spring flowering varieties) now. The easiest approach is to dig away at the outer edges of an established clump but if it is really congested, it will perform better next year if you can extricate some bits from the centre to reduce over crowding. Cut back the top foliage to find the growing tips and replant in well cultivated soil. Feed and water.
If you are growing elegia capensis (an attractive plant which resembles a feathery bamboo and is prized in floral art), now is the time to dig and divide it. It took us a few years to find out in the nursery that dividing this plant in winter does not work and results in death. As it can form a very large clump, digging and dividing it every two or three years means you do not need a front end loader when it finally gets too large.
Plant winter and early spring annuals in trays for transplanting into the garden in a month or two. Pansies, poppies, nemesias, foxgloves and the like are much cheaper grown from seed than bought in punnets or as potted colour. This is a great activity with children. If you have your trays outside on the ground, you will need to use slug bait as seeds germinate but be cautious where you place the baits so that dogs can’t find them.
Trim hedges so that they get a chance to put on a little new growth before winter.
Keep successional plantings of salad vegetables going. Plant winter spinach.
Start the autumn feeding of fruit trees, including citrus. It gives deciduous fruit trees time to take up the fertiliser before going dormant in winter. It is usual to apply a specialist citrus fertiliser (sold at garden centres) but any all purpose fertiliser like Nitrophoska Blue or blood and bone will suffice for other fruit trees. Try and time it prior to rain.
If you are sowing new lawns, you should have started your preparation at this time. The better your preparation, the better the lawn will be. The idea is to get it levelled and allow the first crop of weed seed to come up before raking. This will reduce the amount.