When the lower leaves turn yellow in a tomato plant, the reason can be one of several problems but usually nitrogen deficiency is the culprit.

A plant uses a lot of nitrogen as a nutrient in, for example, its green leaves. If a plant lacks nitrogen, it will take this nutrient from the oldest leaves at the bottom and draw it up to the youngest leaves in the crown of the plant. You can tell it is nitrogen deficiency because the upper leaves are smaller than others lower down and the tomato clusters develop high up in the crown of the plant.

The plant lacks strength and growth.

How can we prevent nitrogen deficiency?

If tomato plants are planted in the ground instead of in pots, there is a small chance of nutrient deficiency. The roots can cover a much larger area in the earth than in a pot and there are often far more micro-organisms (which help the plant absorb minerals) in the ground than in a pot.

Do you still want to grow tomato plants in pots? (They look super nice on a terrace, of course). Then plant them in large pots, so that they have a buffer for water and nutrients. We tell you how big the pot should be for all our varieties.

For soil,the best is a mixture of 50% compost and 50% soil. Mix in some organic fertilizer.

I add a small handful (50 grams) of compost fertilizer per tomato plant.

Even if you grow tomatoes in the ground, you must still fertilize the soil with compost every year.

You take tomatoes from the plant. The plant takes many nutrients from the ground. If you never give anything back, the ground will eventually become exhausted. Digging compost into the soil every year and adding a handful (50 grams) of organic fertilizer per plant during planting ensures that the plants get sufficient nutrients.

egularly giving compost tea to tomato plants increases the number of micro-organisms living around the roots. These micro-organisms help the plant to absorb nutrients from the soil. In return, the plants return sugars to the micro-organisms. There are many types of micro-organisms, all working together in the soil, each with their own task. For example, free-living bacteria (like Azotobacter) capture nitrogen from the air in the soil, and then release it for the plant.

I’m not sure if giving plants compost tea adds to the bacteria in the soil. What I do know is that it stimulates the sum total of life in the soil. Compost tea is easy to make yourself. To find out how, read the article: “What is compost tea?”

A tomato plant loves nutritious soil, because it uses a lot of nutrients.

Tomato plants love nutritious soil, because they need lots of nutrients. Even if you have soil (both in pots and in the ground) enriched with compost and organic fertilizer, it is often not enough for the whole season.

In general, organic fertilizer lasts for about 3 months. So, 3 months after planting, you will need to add more organic fertilizer. If the tomato plants are planted in mid- or end-April, they need to be fertilized at the beginning of July.

Sprinkle a small handful (50 grams) of organic fertilizer lightly on the soil around each tomato plant. Ensure that the grains do not lie against the stem of the plant. Bacteria, which convert the grains, can cause the stem to rot where the soil and air meet around the tomato plant. If you ensure that the grains do not touch the stem, there is nothing to worry about.

If you stick to these tips, you will have beautiful eco-friendly plants with delicious juicy tomatoes all through the season. 😋