Clay soil tends to be fairly problematic especially for new gardeners, the good news is that there are a couple of steps that you can make in order to break down clay soil. Amending clay soil is a form of art, you really need to know a lot about how clay performs in the soil and how it affects the different microbes that live in it. Not all clay soils are the same, some are compacted some are extremely waterlogged and some have their topsoil eroded.
To break down clay soil fast first you need to aerate it and then place on top of it organic material. Organic materials that break down fast like grass clippings, hay, straw, and leaves are the best for improving clay soil. The faster the organic material breaks down the easier the job of microbes, bugs, and worms will be, so take care of them and they will break down the clay soil.
If you want to aerate the clay soil as fast as possible then my personal recommendation is to use a push spike aerator Click here to check it out on Amazon.com
If you have clay soil and you still got some weeds or grass growing on it then that is good news, as breaking down the clay soil will happen relatively fast. on the other hand, if you have compacted, eroded and cracked clay soil then it will take some time until you can actually grow anything in the soil. There are two ways of approaching clay soil when it comes to breaking it down, the organic route with amendments and mulches and the inorganic route with liming agents like gypsum and calcium.
If you want to break down the clay soil as fast as possible then you can use gypsum or calcium, but make sure to test both the acidity and how much clay the soil actually contains. If you do not use the correct measures of gypsum or calcium for your specific type of soil then you will do more harm than good in the long run. If you want to know more about gardening in clay soil then check out my recent article Gardening In Clay Soil ( Top 7 Tips To Improve It ).
Aerating Clay Soil
Clay soil doesn’t let air circulate as it tends to retain a lot of water, the more water it retains the worse the drainage of the soil is and plants will simply not be able to grow in it as sooner or later they will die of root rot. You can aerate the clay soil by using a specialized soil aerator, a pitchfork, or by simply tilling the soil. Aerating the soil will allow air to flow through the soil which is extremely important for microorganisms that will break down the clay eventually.
If you have some grass or weeds growing in the clay soil then you can simply make a couple of small holes in the soil for aeration. On the other hand, if the clay soil is compacted and the topsoil is also eroded then you definitely need to till it. The more compacted the clay soil is the longer it will take for the call to actually break down.
Mounding Clay Soil
Once you have aerated the clay soil it is time to mound it either with organic material like mulches or with soil. As a general rule, you should place the soil on top of the clay and then place the different mulches which you want to use. Mounding the clay soil helps to break down the clay soil as it will allow bacteria, bugs, worms, and plants to grow on the mound and sooner or later they will penetrate the clay soil and decompact it.
You can use potting mix for mounding the clay soil, just make sure to place on top of it a thick layer of mulch to protect it from the weather. How tall and wide the mound should be, depends if you want to grow plants with shallow roots or with deep roots.
Composting Clay Soil
Composting clay soil is extremely important, as compost tends to contain a lot of nutrients and microorganisms which benefit plants. There are plenty of organic composts on the market although my personal recommendation is to use animal manure like cow and chicken manure. These manures usually contain a lot of nitrogen and minerals which the beneficial microbes need, so help out the microbes and they will help you out by making the clay soil fertile again.
Commercial Soil Conditioner For Clay Soil
There are a lot of commercial soil conditioners which are good for clay soil, the trick is to get the right kind for your specific type of soil. Perlite, greensand, lime, sulfur, gypsum, and vermiculture are excellent soil conditioners. These soil conditioners tend to act relatively fast and they will break down the clay a lot faster than simple organic matter, although if you are not careful with the measurements you might do more harm than good. Simply put stick to organic matter if this is the first time you are trying to improve the clay soil.
Mulching Clay Soil
Mulching clay soil will add the much-needed organic matter to the clay soil, as oftentimes clay soil has very little organic material and this is why very few plants tend to thrive in clay soil. If you want to break down the clay soil as fast as possible then use organic mulches that break down fast like hay, straw, leaves, or grass clippings. The faster the mulch breaks down the more bacteria and bugs it will attract which will help with the breaking down of the clay.
You can also use wood chips as a mulch although my personal recommendation is to make a thick layer of organic mulch that breaks down fast and place the wood chips mulch on top of it. Grass clippings, hay, straw, and leaves will break down in a matter of months, wood chips or pine needles on the other hand can take more than a year to break down. You can also use ground cover plants instead of mulch, for more information check out my recent article Ground Cover Instead Of Mulch ( Top 9 Pros & Cons ).
Avoid Compacting The Clay Soil
Once you have aerated and amended the clay soil the last thing you would want is to compact it especially if you have an already compacted clay soil. Once you have prepared the clay soil try to avoid walking on it. It takes some time until the clay soil will be good for gardening, and your main goal is to let the different microorganisms, worms, and bugs do their work as efficiently as possible.
Growing Cover Crops On Clay Soil
Cover crops are extremely beneficial for clay soil, especially once you have amended it. There are a lot of different cover crops you can grow but my personal recommendation is to grow nitrogen fixing plants. These nitrogen fixing plants will actually produce nitrogen with the help of beneficial bacteria, once you cut them down the nitrogen will be readily available for the new crops. The best nitrogen fixing plants for clay soil are fava beans, soybeans, peanuts, and cowpeas.
You can use the cover crops as living mulch although I highly recommend that you still use some type of organic mulches to protect them. If you have snails in your garden then try to avoid using grass clippings as mulch for the cover crops, as this is just an invitation for them to eat the cover crops.
Breaking Down Clay Soil With Raised Garden Beds
With this approach you will be fixing two problems at the same time, you will be able to grow vegetables, and while you are doing that you will also break down the clay soil. Make a relatively shallow garden bed, fill it with organic matter, place some mulch on top of it and start planting. The organic matter, mulch, and the plants will start breaking down the clay soil, and all you need to do is to move the raised garden bed every year to the next location where you want to improve the clay soil.
Just keep in mind to leave all the organic matter and the mulch on the spot where the raised garden bed was, and just simply grow plants in it. This is a relatively slow process of breaking down the clay soil, although if you are short on time this can be an excellent method. If you want to know what to put on the bottom of the raised garden bed then check out my recent article What To Put On Bottom Of Raised Garden Bed ( Top 12 Materials ).
As you can see there are a couple of things that you can do in order to break down clay soil, but you definitely need to start with aerating the soil. Aerating the clay soil speeds up the process significantly, it will allow bacteria, bugs, and worms to penetrate deeper into the clay soil.