Now that growing season is coming to an end, you are probably wondering how to improve your garden soil over the winter season. If you take the right steps now, it will be much easier to get a great harvest from your garden next year.
So, how do you improve garden soil over the winter? Planting cover crops (such as oats, clover, or winter wheat), making adjustments based on soil testing results, and adding compost are the best ways to improve your garden soil over the winter.
Of course, you’ll need to plant your cover crops at the right time to let them grow. You’ll also need to allow enough time for soil amendments to take effect. Let’s take a closer look at some of the ways you can improve your garden soil over the winter.
How To Improve Garden Soil Over The Winter
I’ll try to go in order of some of the best practices for improving your garden soil over the winter. The first step is perhaps the most obvious. Start by cleaning up your garden soil to prepare for the next steps.
Remove Dead Plants From Your Garden Soil
At the end of your growing season, remove the remains of dead plants from your soil. This means pulling out plants along with their vines and roots (you may need to dig them up if the roots go deep).
You should also pick up and dispose of any old or rotten fruit lying around. I like to give these to the chickens or put them in the compost pile.
An important note about this cleanup step: don’t compost diseased plants! If you know that certain plants are diseased, you should pull them out right away and burn them!
You could try to compost diseased plants. However, there is no guarantee that the compost will get hot enough to kill the bacteria or fungus that caused the disease.
My advice is to burn the plants and add the ash to your compost pile for the next season.
Plant Cover Crops To Improve Your Garden Soil
Once the soil in your garden is cleaned up, remove any cages, stakes, trellises, and other tools you used. Now it’s time to plant cover crops to help improve your garden soil.
Cover crops are grown in the fall and are meant to add nutrients, especially nitrogen, back into the soil before the next spring’s planting starts. For this reason, cover crops are often called “green manure”.
Cover crops can also help to keep weeds from growing in your garden and prevent soil erosion. For more information, check out my article on how to prevent soil erosion.
Cover crops should be planted when the soil is still warm enough for the seeds to germinate. This means planting cover crops in late summer in colder areas.
Also, when planting cover crops, combine legumes (such as peas) and non-legumes (such as oats) if possible.
For more information, check out this article on cover crops from the University of Maryland Extension.
Here are some different types of cover crops, along with advantages and disadvantages of each.
- Winter wheat or winter rye – these cover crops help to break up clay soil. However, they create a dense mat of roots, which means they are difficult to turn under the soil without a rototiller.
- Oats – this cover crop scavenges nutrients from soil, suppresses weeds, and prevents erosion. According to agriculture.com, oats are a good cover crop to plant in an area where you want to grow corn.
- Radishes – this cover crop can help to break up compacted soil and releases nitrogen into the soil.
- Triticale – this cover crop grows easily and helps to suppress weeds. You can feed it to livestock if you have them.
- Legumes (Winter peas, clover, vetch) – these cover crops capture nitrogen from the air and fix it into the soil. This is the first step in converting nitrogen from the air into a form that plants can use for growth.
- Barley – this cover crop helps to suppress weeds and prevent erosion. For more information, check out this page on barley from the Sustainable Agriculture Research and Education website.
- Buckwheat – this cover crop suppresses weeds and loosens soil. For more information, check out this page on buckwheat from the Sustainable Agriculture Research and Education website.
Just make sure that your climate gets cold enough to kill your chosen cover crops, or else you will need to cut them down and till them under the hard way!
For more information, check out my article on green manure (cover crops).
Test Your Garden Soil and Make Adjustments
It’s always a good idea to test your garden soil to get an early warning of any problems with pH or nutrient levels.
If you’re not sure where to get started, check out my article on how to do a soil test.
You can also check out my article on what a soil test tells you.
Once you get the results of your soil test, you’ll know for sure whether you need to adjust soil pH or nutrient levels with additives (more information on this below).
Adjust Garden Soil pH
If your soil test tells you that the soil pH is too low (acidic), then you need to add lime (calcium carbonate) to your garden to raise the pH. You can also use dolomitic limestone if you also want to add some magnesium to your soil.
If your soil test tells you that the soil pH is too high (basic), then you need to add sulfur to your garden soil to lower the pH.
If you need to add lime or sulfur to your soil, do it early and give them time to work over the winter. Also, be sure to test your soil again before adding additional lime or sulfur, since it is possible to overdo it.
For more information, check out my article on putting too much lime in your garden.
Adjust Garden Soil Nutrient Levels
The plants in your garden need lots of different nutrients to stay healthy and provide you with a good harvest. The “big three” are nitrogen, phosphorus, and potassium (or NPK).
You can add traditional “NPK” fertilizers to supplement these nutrients. There are lots of different types with different ratios – for example, some have low nitrogen levels, and others contain no phosphorus or potassium.
In addition to standard fertilizers, you can try the following soil amendments, some of which you might have lying around.
- Wood ash – maybe you have a wood stove or fireplace in your house, or a fire pit outside. Either way, you can use the wood ash to add phosphorus and potassium to your soil. You can also mix wood ash directly in your compost pile and put the whole mixture into your garden later. Just make sure to avoid burning pressure treated wood and using the ash in your garden. For more information, check out my article on putting wood ash in your garden.
- Ground eggshells or oyster shells – these will add calcium to your garden soil. The finer you grind them up, the faster the calcium will become available to your plants. Adding ground eggshells or oyster shells in the winter will allow some time for the calcium to become usable to plants.
- Bone meal – this will add phosphorus and calcium to your soil. You can buy this, since most people don’t have it lying around the house.
- Blood meal – this will add nitrogen to your soil. You can buy this product, which is often made from the blood at a slaughterhouse.
- Epsom salt – this will add magnesium and sulfur to your soil. Don’t use this to cure blossom end rot, since it doesn’t contain any calcium!
- Dolomitic lime – this will add calcium and magnesium to your soil.
Mix Compost Into Your Soil
Compost is a great way to recycle kitchen and yard waste while also adding nutrients and organic material to your garden soil.
Compost helps to improve drainage of clay soil, preventing root rot and making it less likely that you will over water your plants. Yes, that is possible – for more information, check out my article on over watering your plants.
Compost also helps to improve water retention in sandy soils, which makes it easier for plants to survive periods of drought if there are watering restrictions in your town.
Among other things, you can use leaves, straw, grass clippings, and fruit or vegetables scraps for your compost pile.
For more information, check out my article on how to make compost.
You can also add manure to your compost pile to give an added nitrogen boost. Just make sure to allow the manure to decompose before putting it in your garden!
For more information, check out my article on where to get manure.
Put Mulch Over Your Soil
Another good way to improve your garden soil over the winter is to cover it with a layer of mulch. Remember that mulch doesn’t just have to be wood chips.
Mulch can also be straw, leaves, cardboard, or even compost itself. Just about anything that will cover the topsoil and break down over time can be used as mulch.
Mulch is a good alternative to cover crops if you want to suppress weeds. It could also be used just between rows to keep weeds from growing there.
Avoid Walking on Soil To Prevent Compaction
Finally, remember to avoid walking on your garden soil as much as possible. Otherwise, you will compact the soil, which in turn reduces the air and water available in the soil.
By now, you have a good idea of the steps you can take to improve your garden soil over the winter. If you do the work now to prepare for next spring, growing a good harvest will be much easier.
I hope you found this article helpful – if so, please share it with someone else who can use the information. If you have any questions or advice on improving garden soil over the winter, please leave a comment below.