How to Make Perfect Garden Soil in Winter

Great soil means great plants, and winter is the perfect time to build soil health ready for the next growing season. The easy methods below will nourish your soil without the need for expensive bought-in fertilizers or amendments, using materials that are easily sourced very cheaply – or even for free!

Putting Garden Beds to Bed

Garden beds begin to empty as autumn crops are harvested. You can build fab soil around actively-growing crops too – and I’ll explain how to do that shortly – but first, let’s put those bare beds to bed!

The aim is to replace all the nutrients that were taken up by growing crops and then lost when the vegetables were harvested or cleared away to the compost heap. If we never replaced those nutrients, the soil would gradually become depleted and poor. Future crops just wouldn’t grow well.

To reinvigorate the soil we need to add organic matter, which is just any materials derived from living things that can be used to improve soil structure and feed the plants grown in it. Two of the very richest options are garden-made compost, and manure.

Manure doesn’t need to be completely rotted down to add to beds at this time of year, because it will have all winter to break down further. Nothing will to be planted for several months, which should give nature plenty of time to build your soil. Spread manure or compost a couple of inches (up to 5cm) deep, then roughly level it off with a rake or the back of a fork.

You could leave it like this, but if you have wood ash you could sprinkle a thin layer on top too. I also like to finish with a layer of leaves – it’s free soil food after all! Leaves can be laid several inches thick to help prevent erosion of the soil caused by winter weather. If you’re gardening in a colder climate then a layer of leaves will prove incredibly powerful, adding a generous layer of insulation which will keep your manure or compost and the soil beneath a touch warmer. That means soil life such as worms will remain active for longer – an important consideration if you’re to have good, crumbly soil to plant into by spring.

Leaves scatter easily due to wind or animals. To prevent this from happening, cover the leaves with insect mesh or netting secured at the sides with bricks or boards. In time the rain will help the leaves to meld together, but the cover will hold everything in place until then.

If you tend to get a lot of snow in your garden, great! Snow does the same job of weighing down those leaves, and it will add yet another layer of insulation for the soil way down below.

The manure or compost and much of the leaves will become incorporated into the soil over winter, and by spring you’ll have a lovely rich, friable soil to plant into. If the leaves aren’t quite decomposed, just rake them aside and add them to your compost heap or use them for mulching elsewhere.

Improving Soil Around Crops

We can also improve the soil around actively growing crops by spreading organic matter around the plants. Homemade compost doesn't need to be completely broken down, so if there are still twiggy bits in it, don't worry - it will be absolutely fine to use around well-established plants.

Crumbly, well-rotted compost will bed down nicely, so a depth of a little over an inch (3cm) should be fine for this purpose. Spread it around the plants, right up to the stems. You could, if you wish, add a layer of leaves too – just take care not to bury the plants.

What we’re doing here is mimicking nature, which rarely sees bare soil. Keeping soil covered ensures the life within it always has something to work on. It will feed the worms, fungi and bacteria that make the soil, and they in turn will help plants to access everything they need to grow strongly, including those vital nutrients.

The Dangers of Using Manure

A word of warning about manure: it is amazing stuff, but it’s essential to get it from a trusted source. You don’t want traces of herbicides like aminopyralid in the manure, so make sure that the animals that produced the manure have not been grazing on pasture treated with weedkillers. Herbicides that persist in manure can kill your crops, so ask before you collect it. If in doubt, look elsewhere.

If the only manure you can find is very fresh, just pile it up and leave it alone to break down and mature for a few months. Once fully rotted it becomes dark and crumbly and looks more like compost.

Instant Compost Mix

If you don’t have access to manure or enough compost, you can make your own instant compost mix to lay directly onto beds. It’s really simple to do by mixing drier ‘brown’ materials with fresher ‘greens’. Start by scattering a generous layer of leaves over the ground, and then a similar depth of greens – you could for example use grass clippings or old cover crops. To mix it up, just run over it all with a lawnmower.

This will produce a lovely mix of shredded materials that can be used on beds in exactly the same way as compost or manure. These smaller fragments will knit together easily so they don’t blow away, and they’ll quickly rot down into the soil.

Woodchips for Paths and Protecting Soil

Woodchips are a fantastic source of food for your soil. I like to use them to top up my paths because they create a fairly dry, free-draining surface that’s less likely to churn into a muddy mess. The roots of surrounding plants can still grow down and out into the paths, while all of the fungi in the soil will help to transport nutrients trapped in the path to the crops nearby.

Woodchips are great to use around perennial crops like fruit trees and bushes because they’ll rot down slowly over time to release their nutrients in a more sustained way. Get them in place any time between now and midwinter. Remove weeds, then spread your woodchips to a thickness of about an inch (3cm). Keep the woodchips away from the main stem of woody plants, because damp woodchips piled up against the bark could cause issues with rot.

Woodchips are very high in carbon, requiring nitrogen to break down effectively. It’s not a good idea to dig woodchips into the soil because they will temporarily lock up the surrounding nitrogen, potentially depriving plants of essential nutrition. However, there’s no such problem when they’re used on the soil surface as a mulch.

You may be able to source woodchips for free from a local tree surgeon or by signing up to a site like getchipdrop.com, which connects arborists who create lots of woodchips with gardeners who want them – a win-win relationship right?!

A great option if you want to make lovely rich compost from woodchips is to layer them with fresh, nitrogen-rich materials such as manure to make your own special blend. Stack it out of the way for a year or so to rot down into compost for general use in the garden.

Between woodchips, local manures, collected leaves, compost and harvested green materials you’ve got all you need to build amazing soil and keep plants gloriously happy!