Mid-winter murders are what gardeners traditionally did during the dark, cold months of the year, not necessarily offing their neighbours so they'd be nought but compost by spring (I really have been reading too many murder mysteries) but using the "cold and nothing growing much" time of the year to get rid of pests.

Pests do very little in winter. (I am talking small pests here, not possums, who enjoy midwinter feasting and wassail, or feral goats). Many pests use the time to turn from one state into another - i.e. see winter out either as a cocoon or eggs.

This is one reason for the old-fashioned gardener's trick of covering the trunks and main branches of fruit trees with a thick sludge of compost and manure applied during a dry month when it will stay on for at least a few weeks - it not only suffocated pests during winter but, as it washed down off the tree, it fertilised the tree in spring. Codlin moth, oriental fruit moth, wooly aphids all pass away under "gardener's paste".

It occurs to me that gardeners who disliked their neighbours might have applied this instead of bumping off said neighbour – the pong from gardener's paste must have lasted for months.

These days you can do the same with a white oil spray - no pong, suffocates pests, cocoons and eggs and can be obtained ready-made at your friendly garden centre. Apply according to directions. The white oil, possibly with added pyrethrum if you have aphids or other sap-suckers still operating through winter, is also perfect for attending to the leaf miners that plague citrus trees.

The other mid-winter chore is to spray your fruit trees, berry canes and rose bushes to prevent moulds, blackspot, curly leaf, brown rot, apricot freckle, etc etc. All manner of moulds and fungus lurk around waiting to infect your trees – bark, leaves and fruit – once the weather is warm and moist. You can spray most dormant deciduous trees and shrubs with lime sulphur but don't use it on apricots. For apricots stick with a Bordeaux/copper-based fungicide.

I tend to spray all the fruit trees, berries and roses on a still sunny day with a lime sulphur spray in mid-winter (with the exception of the apricots) and then repeat at bud burst but using a copper-based spray for the lot.

If you can, do preventative fungicidal sprays each winter and early spring you will be surprised how much you can reduce your losses through nasty rots, mildews, moulds and allied diseases. It is always heartbreaking to rejoice in the froth of spring blossoming, count the tiny little fruits as they set, peruse recipe books and clean up the Fowler's Vacola kit ready for the excess as they swell … and then weep as they rot and shrivel on the tree.

Mid-winter was also the time to 'clean up' the garden, i.e. the patches of leaves and corn stalks and prunings where snails, snail eggs and slaters might overwinter. Even these days this is a good time to consign them to the compost bin where, hopefully, it is too warm for the snails to survive or run the mower over them which will do the trick nicely too, and turn the mess into neat mulch.

Your lawn mower is also a useful device about now to pick up any unraked autumn leaves, now soggy brown winter leaves. If your mower has a catcher it will shred the leaves and gather them up for you. Even if it doesn't have a catcher shredding the leaves is still a good idea as shredded leaves have less aerodynamic ability and so tend to stay where you have put them, either as mulch under trees or over a sunny patch of unwanted weeds or grass to kill what is underneath leaving well-aerated loam once you rake the stuff away in spring, perfect for planting melons or pumpkins.

You can also try the 'killing them with kindness' cure for lawn weeds just now: ladle on sulphate of ammonia and they will die, but come spring the fertiliser will have been watered in by the time it – hopefully – decides to rain properly again and the lawn will quickly take over where the weeds have been. A jug full of near-boiling water poured on lawn weeds does the trick too, though if you have many weeds you may need many jugs. On the other hand, if you kill one weed with every breakfast cuppa you will have disposed of 365 by this time next year.

Personally, I am more tempted by planting just now. There is the hint of spring in the air (possibly the scent of jonquils and fattening fruit buds, with a hint of wombat) and the new seed catalogues have arrived and I want to plant everything. Now. Even with frost and no rain and wonky knees. But I shall be virtuous and stick to death to pests, weeds and fruit rots instead – for a few weeks more, anyway.