How To Make Potting Soil For Tomatoes – Easy To Do But Still Needs Some Guidelines

From time to time every gardener (myself included), asks himself the question “How can I improve things?” How can I make potting soil for tomatoes, for example? In the past several years, I have asked myself the same question, although I was shopping tomato soils online and in person.

Luckily, I have picked up a few tricks along the way and decided to make my mixture. This is the road I had to traverse, in order to be a better gardener.

How To Make Potting Soil for Tomatoes


Why Tomatoes In The First Place?


The answer to this question is straightforward. I love tomatoes. They are among my top favorite salad vegetables, besides cucumbers and lettuce. Their perfect smell of spring and life paired with a couple of hard-boiled eggs with a pinch of salt is all which is required to make me one happy gardener.

But, here are some general facts concerning tomatoes:

  • Its fancy, Latin name is Solanum lycopersicum
  • Its name is derived from Aztec word tomatl
  • Technically speaking, it is a fruit, berry-type
  • sun-o
    It is perennial in its natural habitat and annual in temperate climates
  • sun-o
    Tomatoes are sown about four weeks before last frosts in spring (for starting in trays) or when the temperature of the soil settles between 75 and 85 degrees Fahrenheit for successful germination
  • sun-o
    Due to high amount of different varieties, time frame for harvesting is replaced with color; I pick them when they are ripe and red

When To Start Preparations?

When To Start Preparations

Truth to be told, the answer to this question cannot be given universally. Since the title consists the word “potting,” you probably figured out by now that this guide primarily focuses on tomatoes planted in pots (of course!). Since this approach can be taken any time you want, you can prepare it whenever it suits you. But to be honest, I have started one week before the date I set for planting, but it wasn’t enough; give yourself two weeks window.

Of course, if you are growing tomatoes under the UV lamp, it doesn’t matter is it October or March. But, I was raising my plants in windowsills. Therefore I had to rely on a natural source of the sunlight. Since they require a lot of sunshine (six hours is a minimum, while the best results are gained with eight or more), I strongly suggest to avoid if it is possible those “dark months” especially December and January; daylight and the amount of it is too scarce.

It is possible that some woodwork will be required (yes, you read it well), to make a crate of a sort in which the soil will be mixed. If you are unskilled with the hammer, ask someone who is to lend you a hand. If nothing else works, a large bucket will do the trick.

Four Foundations Of Every Great Soil

Whenever I was making soil mixture, I had to take into consideration four factors and to balance them accordingly. These four elements are:





These four factors are making a growth possible. Since every kind of plant requires its specified terms, tomatoes will need proper nutrition, well-aerated soil and the one which holds moist well without retaining too much water. These are adjusted with the appropriate appliance of individual elements, which will be introduced in the next chapter.

Before proceeding further, note that soil which is used or sand might need to be sterilized, to remove fungi or other microorganisms which may appear later and cause troubles. To do so, spread the material in a shallow pan and bake it in the oven at about 200º F for 40 minutes. This way the soil is safe for further usage.



The “feeding” part of the mix should contain some manure or fertilizer; there is no doubt. Few can compare with nicely done home-made compost. Of course, I had to pay attention to how much N-P-K nutrients are present in the mix. This is quickly checked by using soil test kit.

At the beginning of sprouting and until first fruits, it is a general rule to increase the amount of nitrogen, since it builds up stronger stems, roots and other green parts of the plant. Later, when fruits appear, switch on to more potassium and phosphorus, since those elements are influencing the size of fruits.

Of course, if you are uncertain, make as mild mix as possible, because tomatoes are tender plants in general, and can get burns from too much fertilizer easily.



The amount of air which is contained in the soil should be as high as possible. This is achieved by applying various ingredients within soil and turning it over. This way I got rich and lovely hummus which was used for planting.

Speaking of which, I forgot to tell you never to use ordinary soil from the garden. This dirt will get dense very quickly, squishing out all the air, and leaving plants suffocating. However, there is a way to correct this as well. Start by filling medium-sized crate or large bucket with soil, and add every piece of plant waste you can find. Leaves, straw (my favorite), old and spoiled potatoes, egg shells even. Turn the mixture with a pitchfork once a day for two weeks. You will notice that the soil gets kind of fluffy texture and that a handful of it seems lighter.

If you did everything as described and the result is lovely aerated hummus, you should be proud of yourself; you have learned something new as well. Of course, if you are tight with the schedule, you can always buy a bag of premade hummus and use it.



The ability of the soil to retain water moist, without making a swamp-like bog is what I have aimed for. Surely, if I were growing rice, the matter would be different, but in this case, some moist was required, but not too much of it.

Usually, hummus is the element which retains moist, since we threw in everything said above, but there are several others which can help you to hold a bit more water. Garden loam is among the quickest solutions, mainly if you have grown plants which were nutrient-hungry such as cabbage or potatoes. Loam left after the latter tends to be better, just because while taking the potatoes from the ground you turn the soil and break any possible lumps.



I knew that the extra water had to be drained out, so I had to let it go (and now I have Elsa stuck in my mind singing her heart off). Anyway, some of the most often used materials for improving drainage are sand or perlite. Sand is excellent because it is easy to find, but the problem might be seeds and microbes which are contained within, which can cause some troubles along the way. Therefore, perlite sounded like an excellent solution to me, and thus the purchase was made.

The best thing about making this mixture is that you can adjust it quickly later, only by adding more of the responding element.

Grab A Shovel; We’re Mixing!

Remember when I said that some woodwork would be required? Now is the hour. If you don’t have crate large enough, you can make one quickly, and make mixing there. It mustn’t be as fancy as this one, but still, you can use the guide, the principle is the same.

I have used an old bathtub. It sounds ridiculous, I know, but I have an old one which I’m using for mixing such things and cooling down watermelons during summer. Anyhow, the measure of ingredients should be 1:1:1. You are probably asking what the third component is.

The bulk of this mixture wasn’t hummus, in case that you are wondering. The central part consisted of peat moss. Since there is no other way to obtain it other than purchasing, you can hop to the nearest garden center or order it online. 

Grab A Shovel

Luckily, this is not something expensive and can be sold in bulks as well. Some people are using coir as well, but I felt that this material is too water-demanding, so I opted for the first one.

First of all, I had to prepare peat moss, so I have soaked it in water with 2:1 ratio where two parts are the moss and one water and waited a bit for all the liquid to be absorbed. After a few turns with a shovel, I have added two of the remaining ingredients and continued to mix it well. Also, if you find at one moment as I have that the shovel is too inconvenient, use a hoe instead. It will help you to turn over those hardly reachable spaces.

What To Do After?


Since the majority of the work is done, all there is left is to store it for later use, or use it immediately. In case that you won’t be needing it right away, just put it in a bucket, seal it tight and leave it somewhere dark. You will have fresh potting soil at your disposal, and you can change it whenever you see fit.

Also, if you are planning to prepare the soil for starting tomatoes in beds and switching them to the garden later, the procedure is the same, only that more nitrogen should be added when the seeds are sown, so it will sprout faster and be stronger overall later. 


So, there is my guide; I sure hope that it was helpful. Now you know how to make potting soil for tomatoes, so this can keep you occupied during winter. This approach is also more or less general, so you can use it for almost any other plant which requires similar type of soil,

In any case, feel free to share your comments, thoughts, and opinions in the comment section, I’d love to hear back from you!

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