Autumn is my favourite season, but sadly, it is a precursor to my least favourite season, winter. However, time marches on and the seasons come and go, so there is no alternative but to start preparing the garden for the cold and wet months ahead. The most important task is applying mulch. A layer of mulch keeps weeds from germinating, slows the cooling of soil overnight and the organic matter helps keep beneficial microbes active and root systems healthy, important for protecting plants from winter root diseases.
We get our mulch from shredded tree prunings and seagrass harvested from beach piles left after north-easterly storms. The seagrass is particularly good at mulching our vegetable beds, forming a very dense and nutritious layer that takes all winter to break down. In the absence of those free mulches, pea straw, commercial woody mulch or municipal compost can all be used. Avoid thick mulches of lawn clippings though, as they tend to create a slimy anaerobic layer which can harm more than help. You are better piling clippings up in a corner to hot compost, then use a year or so later.
A hot compost is good for dealing with diseased plant material as well, but make sure that the heap gets hot enough (between 55-70C is recommended) over several days to kill the disease spores of blight, rust and mildews. Small particle size is ideal for creating a hot compost, so using a shredder or running over the plant material with a lawn mower and catcher is a good way of achieving this. In my garden, I spread the diseased material over the lawn and just mow it in to feed the lawn instead, preferring a cold compost heap as the easier style of composting (much less work!). Either way, the compost will be very useful next spring.
The lawn mower also comes in useful for dealing with any windfall fruit that are too damaged or infested to harvest. These otherwise rot under the trees and generate the next season’s pest infestation. I flick the fruit out over the lawn before mowing and the birds move in afterward to eat the fruit scraps and any larvae that they contain. Slug and snail control is another important task at this time of year. A light scattering of slug pellets around the garden gets the slugs and snails before they go into winter dormancy. A pellet or two every square metre is enough. You are better to repeat the exercise every couple of weeks, rather than cover the garden with pellets, as slugs and snails can smell food up to several metres away.
My shrub and tree pruning starts in late summer with the plums, peaches and nectarines. It is a good idea to prune these in the north as soon as possible after harvesting the fruit. This helps reduce the chance of silverleaf disease, which readily infects cut wood during cool, damp conditions. Stone fruit are often a little vigorous in the north as well and pruning in late summer to autumn also removes some of the excess vigour.
Any overly vigorous plants like Robinia Mop Top and most cane berry fruit are best pruned now rather than in winter for the same reason. Also good to prune in autumn after the main flowering season are herbs such as English lavender, rosemary, sage and thyme. It is a good time to prune most hedges as well, as there won’t be a lot of regrowth until next Spring. Then, it’s time to hibernate yourself with a good book, mulled wine and a toasty fire!