Planting Tomatoes in Clay Soil

I live in a flower pot. The ground is orange, no matter how much manure and humus is added to it.

Have nothing besides lumpy, sticky red clay in your gardening spot? Learn how to get tomatoes to thrive no matter how gooey your ground may be. Read more now.

The soil is so hard that it cuts into the stalks of most vegetable plants. The tender plants must be hardy to survive the difficult climate we live in.

But we give them a fighting chance.

Use the tips below to get your tomato plants to grow successfully in hard clay soil.

Here is what we do:

First we grow our seedlings indoors until all danger of frost is past. Or we buy healthy ones from a nursery.

The shoots should stand about eight to twelve inches out of the soil before transplanting. The roots should be healthy. We take them outside in the daytime and bring them in at night for a week before planting them in the garden, to harden them to the climate.

We don’t plow the ground. It’s a waste of time. It hardens up almost immediately.

We dig a hole with a shovel about one foot deep and one foot wide. Into this “soil” we mix one shovel full of compost (which has decomposed for at least a year), one shovel full of manure, and one shovel full of wood ashes.

If you don’t have wood ashes, you can add half a shovel full (about two cups) of agricultural lime. If we have time-release vegetable fertilizer or Epsom salts, we add about ¼ to ½ cup of this to the pile.

Mix these ingredients into the original soil thoroughly, and put it back into the hole.

Do this for each tomato plant, spacing the holes about two feet apart.

We take a small garden spade and dig a smaller hole about six inches deep in this softened soil. We remove the bottom leaves of the seedlings about halfway up the stalk.

We plant the seedlings in each new hole deep enough that the bottom leaves just clear the dirt. All the little hairs on the stalk will form roots whether you bury them or not, so it’s best to bury them.

Besides, tomato worms look exactly like tomato plants with roots protruding from stalk, so it’s best to cover the stalks so the worms are more visible, and can be removed easier.

Then we push the ground down to compact the soil around the young plant, to hold it in place through rain and wind. This also allows the depression to collect rainwater to nourish the roots of the plant.

Staking tomatoes plants being grown in clay soil |

We now push our four-foot-long tomato stakes into the ground about a foot deep and six to ten inches from the stalk, helping to make sure it won’t fall over in the future.

Why do this now?

Well, the ground is soft. It won’t be this soft again. You’ll never get it into the ground later without a two-pound hammer.

We place a copper object near the stalk.


Copper conducts electricity with the iron in the soil, and helps to deter insects from crawling up the stalks.

The best conductor we have found is a foot-long piece of fine copper wire formed into a ring around the stalk, at least three inches in diameter. Any smaller and you risk strangling the stalk as it is growing.

When we have all of our plants in place, we cover the ground with three to four sheets of newspaper. This holds in moisture and prevents the growth of weeds.

We cover the paper with four or five inches of grass cuttings or leaves. This prevents the paper from blowing away.

We pour two quarts of water near the stalk, taking care not to remove the soil that is holding the plant in the ground.

We will make sure throughout the rest of the summer to water it morning and night (unless it rains), taking care not to get water on the leaves. This is because the magnification of sunlight on the wet leaves burns them.

Successfully Growing Tomatoes in Poor Soil

As the tomato plants grow, you must keep them from lying on the ground. The tomatoes that hit the ground will rot easily. You may use strips of cotton jersey from old t-shirts or nylon hosiery to tie them loosely to the stake.

Well, that’s the gist of it.

Many people wonder which leaves we take off, since it is general practice to remove the “suckers.”

My father taught me this: leaves contain chlorophyll, which creates sugar. Without chlorophyll, you will have no sugar.

If you want sweet tomatoes, keep as many leaves as possible. Your tomatoes will be smaller, but they won’t be watery, and the flavor is unbeatable.

If you wish, you may remove the leaves around the green tomatoes so that sunlight will hit them, and they will ripen faster.

How do you keep tomato worms away from your plants?

According to Arizona State University’s School of Live Sciences, insects breathe through holes in their exoskeletons called spiracles. If you use any kind of powder on the plant, this will help to deter the insects.

We have used flour and baby powder, as well as the insecticide rotenone. All can be effective. You must be vigilant, however, since the worms blend into the plants and the rain washes off the powder.

One more note: never, ever bury the plants in the soil you will grow them in next year.

Moths, which produce the tomato hookworm (Manduca quinquemaculata) and the tobacco hookworm (Manduca sexta) – both of which look similar and both of which feed on tomatoes (and tobacco) – will have laid their eggs on the plant, and you will have harvested many annoying insects by doing so.

It is best to burn the stalks or carry them far, far away.

Got any tomato growing tips to share? Let us know in the comments!

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W. LePage
W. LePage

I find your statement to remove leaves so sunlight will hit the tomatoes and they will ripen faster a bit odd. I learned in school many many years ago that sunlight results in the production of chlorophyl which I believe is the source of green in plants. Wouldn’t direct sunlight enhance the production of chlorophyl and prolong ripening? I always store pre ripened tomatoes in dark places to enhance ripening. Is this not a good idea?

Allison Sidhu
Noble Member
Allison Sidhu

Hi W.,

Thanks for reading! You’re right about chlorophyll- but this doesn’t affect the ripening of fruit. Heat actually helps to speed this process along, and tomatoes release ethylene gas. It actually helps other fruits nearby on the vine to ripen as well- the same process that takes place when several unripe toms are places together in a closed paper bag.

Pretty neat, huh?


I’ve tried this in the past and the hole fills up with water in any heavy rain storm since the clay soil doesn’t let it disperse and the plants eventually drown and rot away.

Adam H
Adam H

I have had that problem a bit. I dig bigger deeper holes, like 2.5 deep by 2 feet wide. Then, after the plant grows a bit, I spread mulch about 3 inches deep over the soils.

The clay is so bad here that my crawl space sometimes floods and doesn’t drain for a week!


What I found that seems to work…is taking some plastic drink bottles cutting off the very bottom portion so the top is straight and push the top down into the fertilizer/mulch and whatever (like Nitrogen and other products). Now what do you have? A plastic container with a drain spout directly to the plants ROOTS…uh, ask Alex Hailey about Roots and not me….just trying to be politically correct (don’t you see?)…anyways….a source to keep those roots wet….but don’t ever forget those healthy watered plant roots can NOT penetrate cement like soil in the hot, summer time…when the tomatoes should be… Read more »


Hi this is my first time having a garden I planted from the sides 45 tomatoes and 12 peppers in my garden that has clay type soil. When I started the garden I shaved the grass off then I flipped the soil over to make sure the weeds will not come back. I planted the seed of tomatoes and peppers in the house. One and a half weeks later I planted them in the garden. Now, 2 months later, the tomatoes are 2 to 3 feet tall with 🍅 on them, flowers and blooms. Most of my tomatoes have one… Read more »

Allison Sidhu
Noble Member
Allison Sidhu

Sounds like you’ve made good progress so far this season. Do you know if you are growing determinate or indeterminate type tomatoes? Determinate plants are usually smaller when mature, and they will produce a single harvest with fruit that ripens all around the same time. Indeterminate types will continue to grow throughout the season, with a continual harvest. Rather than letting them spread on the ground, they should be staked in some way that will allow them to continue to grow taller through the summer. I’m not sure exactly what you mean re: the big, funny-looking tomatoes. Can you attach… Read more »

Tom H.
Tom H.

I save egg shells, dry them out, grind them up, then add them to soil for calcium.

Also, if I do the inverted tomatoes I like to hang them on the south side of the brick house. I have harvested tomatoes as late as November, in Detroit, Michigan that way, because of the heat to the plant during the day and the bricks give off warmth at night for a longer growing season.