Growing Tomatoes in Clay Soil: This Is How You Need to Do It

Why Do Tomatoes Have a Problem Growing In Clay Soil?

While tomatoes can deal with wet feet to an extent, long bouts of wet weather can trigger an array of fungal issues and bacterial disease. If you have mulch around your plants, the moisture issue will be compounded, increasing the risk of illness among the plants (you may spot mushrooms growing around your tomato plants, too.)

In addition, the inability to reach roots out far and wide will hold your plant back for a while after transplanting, but eventually the plants do take off. It’s very difficult for the tomato plants to send their roots out, especially in compacted clay. If you begin to see signs of transplant shock, such as stunted growth, your plants should be fine; you’ll just have to wait a bit longer for ripened fruit.

How to Make Clay Soil Easier to Grow Tomatoes and Other Crops In

If you want the simplest answer, we’ll start with adding amendments to the soil.

The greatest soil still has a certain percentage of clay; it’s a valuable part of an enriched, healthy, fertile soil. This process is easier to manage when growing tomatoes in containers, which is why many opt for container gardens.

However, having too much clay results in compaction and drainage issues, which is primarily what you’ll be dealing with. Oh, and clay soil is very hard to work, which you’ve like discovered. I’ve broken my fair share of garden tools, and I’m sure you have, too.

Adding Humus and Compost

Humus and compost will go a long way in diluting the clay that you have in your garden soil. It’ll break up the clay particles, give you more of a loam soil, and it’ll improve drainage.

It may take a few years to achieve the dark, beautiful, dreamy loam you’re after, but you will see significant improvement with each passing year. Your tomatoes will thank you immensely as the years go by!

Adding Wood Chips to Garden Soil

Many people will suggest that you add wood chips to your clay garden soil, but I strongly advise against this. Your garden will be robbed of nitrogen as the wood decomposes.

If you would like to use the wood chips as mulch, that is fine; you still may require additional nitrogen to keep your soil balanced, though.

Adding Lime or Gypsum

Both lime and gypsum are helpful in breaking up clay and improving soil structure. Gypsum is recommended over lime generally, but it truly depends on what’s in your soil. Please have a soil test done through your county’s extension office before adding these amendments, so that you know exactly what you need.

Lime will alter the pH of your soil, and you don’t want your soil’s pH to swing too harshly in one direction; when the pH is not balanced, certain minerals or nutrients become “locked up.” When this occurs, even if the soil has plentiful amounts of a nutrient or mineral, the pH level of the soil prevents it from being taken up by the plant.

One of the most commonly experienced scenarios of a “locked up” mineral is blossom end rot. Many people see blossom end rot, and assume that their plants have a calcium deficiency; they then assume that the soil is deficient. In many cases, it’s simply a water-related issue. I rarely have BER issues- but when I do, I always give the plant some water to address it, and give it a week to see if the rot disappears. It always does!

Aerating the Soil and Eliminating Compaction

Clay soil loves to settle and compact down, and this is what makes it so difficult to work with. Simply eliminating compacting and breaking up the clay makes it much, much easier to work in! However, the soil will pack down again over time. In addition to adding amendments, try these tips.

Tilling When the Time Is Right

There is a right and a wrong time to till. Trying to figure out exactly when to bring out your tiller is the hard part! Tilling introduces air into the soil, making it lighter and fluffier. Breaking ground is one of the most labor intensive part of gardening.

You should not till when the soil is wet, as wet soil means the clay will stick to the tiller and it’ll only become further compacted. This is the opposite of what you want.

When the soil is dry, your poor tiller is going to have a hard time breaking through it; don’t put this kind of strain on your tiller. Instead, wait until a few days after a good rain.

When the soil is right, it’ll crumble in your hand with ease, with moisture being visible; it will not be slimy, it will not coat your hands with mud, and it will not be rock hard. These days are few and far between, so be sure to till when the first opportunity arises.

Never Step Foot In Your Garden

When you walk through the garden, you are undoing all of your hard work of tilling, amending, and aerating the soil. Stepping through the garden compacts the soil, which can be seen in the footprints that are left behind. Cats and dogs can compact the soil as well, so be sure to keep them out of the garden if possible.

Instead of walking through the garden, lay down wooden boards to help disperse your weight when working in the garden. Staying completely out of the garden is a novel idea, but we still have to weed, harvest, and prune plants. These boards will allow you to get close to your plants, without causing as much damage to the soil structure.