Gardening – Bedding down for winter

The short, grey, cold, damp days of winter can be a hard time for both gardeners and their crops. With some preparation, it is possible to make life a bit easier for both.

Bare soil is an invitation to weeds – generally, there aren’t as many beds needed for winter crops as there are for summer. Replace summer crops with fast growing crops such as lettuce and spinach to take up the slack until your winter brassicas start coming on. Big beds of onions, garlic and leeks are another good use for all that space, while carrots are an excellent choice as they can be left in the ground for quite a while over winter.

You can mulch bare soil or take advantage of the down-time to grow a green crop such as clover or peas to add nitrogen to the soil, or barley and oats to suppress weeds and add organic matter, or brassicas such as mustard to reduce pests in the soil via compounds produced by the roots. Green crops also help prevent the soil washing away or compacting from heavy rain.

Sensitive crops that haven’t finished can be protected by using frost cloth or cloches. These temporary covers reduce wind chill, trap some of the sun’s rays and reduce heat loss overnight. An easy way of making these is using hoops of number 8 wire pushed into the ground or attached to your raised bed edges. Drape the cloth or plastic over these and tie down with loops of string. This keeps the material off the crop and stops it blowing away in gales.

It’s best to prepare your soil during the warmer, drier months of autumn as the soil is easier to work, and the climate is more favourable for working in but, most importantly, working wet soil can break down the soil structure, leading to compaction, which is not good for plant roots. The recent cyclone might have put paid to this strategy, but I’d expect a bit more dry weather to come before winter really sets in.

I like to add a 2-3cm layer of compost to each bed and sprinkle dolomite and gypsum over this. This combination is like gold for earthworms and microorganisms. Lime (including dolomite) and gypsum need time to dissolve and move through the soil, so a winter application is a good idea. Other fertilisers dissolve more readily in heavy rain and tend to leach more easily out of the soil, so applying these just before the crop is planted is a better option.

To reduce disease risk over winter, and cut down on pests and diseases next summer, remove any weeds and old vegetation from beds and paths. Disease spores and pests will hibernate on these. Give any surrounding trees and shrubs a good haircut. The winter sun sits lower in the sky so nearby trees shade more.

Most crops hate wet feet and many soil-borne diseases thrive in wet conditions. If your beds are not already raised, now is a good time to do this. Raising the soil level by even a few centimetres can improve drainage, which also keeps the soil slightly warmer. A raised bed can be as simple as digging out paths and using this soil to mound up the beds or keep your knees off the wet ground by using wide edges such as sleepers – they are great for kneeling or sitting on when gardening.