Fertilize tomatoes: how often, when and with what?

Tomatoes need a consistently high amount of nutrients for the development of flowers and fruits. In addition to choosing the right fertilizer, the amount and frequency also play an important role. All essential information for an optimal dosage can be found here.

A full supply of nutrients is essential for heavy consumers. Tomatoes therefore need fertilizer at regular intervals. This guarantees lush flowering and thus fruit development. It is also an important basis for a healthy immune system.

Essential minerals

A full supply of minerals is essential for many reasons. Among other things, it is necessary for a good immune system. In addition, it is also essential for lush fruit development. The following nutrients are required over the entire life cycle:

• calcium: 2.3 grams, essential for deacidification, excess leads to stunted growth, deficiency leads to alkalinity
• Potassium: 3.8 grams: essential for photosynthesis and fruit development, excess is harmless, deficiency for curled leaves and tasteless fruits
• Magnesium: 4 grams: essential for the water balance, excess is harmless, deficiency leads to yellowing of the leaves
• Phosphate: 0.5 grams: essential for all metabolic processes, excess is harmless, deficiency leads to yellow-brown leaves
• Sulfur: 0.7 grams: essential for the formation of enzymes and amino acids, excess leads to acidification, deficiency leads to yellowing of the leaves
• Nitrogen: 3 grams: Essential for chlorophyll formation and growth, excess leads to tall growth, deficiency leads to stunted stature

The requirements of the individual varieties may differ slightly from the above information. Therefore, find out about the exact conditions in advance.

Tomatoes fertilize in the development stages

The life cycle of the tomato plant consists of three developmental stages. Nutrient requirements vary by phase. It increases steadily with age.

• seedlings: no fertilization necessary
• young plants up to an age of two months: low nutrient requirements of one tenth of the listed values ​​per single application of fertilizer
• adult plants: Consistently high nutrient requirement of four tenths of the listed values ​​per single application of fertilizer

Frequency of fertilizing

How often the tomato plants have to be fertilized depends on their stage of development and on the variety. As mentioned earlier, no additional minerals should be added to seedlings just yet. Young plants should be slowly introduced to the regular fertilizer application every three weeks. Adult tomato plants need a new supply of nutrients about every two weeks.

In relation to the individual variety, there may be slight differences in frequency. Particularly high-yielding varieties generally require more minerals. These species include Celsior, Siberian pear, black cherry, and sugar grape, among others. In contrast, genera that are descended from wild tomatoes tend to be undemanding.

fertilizer selection

In order to fertilize as naturally as possible, the use of an organic fertilizer is recommended. Alternatively, however, the use of a mineral fertilizer is also conceivable. However, this can lead to over-fertilization. Particular attention should therefore also be paid to the nutrient composition of the individual product. However, under-fertilization can also lead to serious impairments.

Consequences of over- and under-fertilization

Growth disorders (height or stunted stature)

Growth disorders are among the most common consequences of insufficient fertilization. The nutrient nitrogen is the main driver for the faulty development. Too high a proportion leads to uncontrolled growth in height. In contrast, undersupply leads to stunted growth. Regular external inspection of the plants is therefore essential. As soon as signs of unusual growth can be seen, the first measures should be taken. Water the plant liberally to flush out excess nutrients.

Discolored and deformed leaves

The discoloration of the leaves usually only occurs when there is insufficient supply. In addition to a lack of magnesium, phosphate and sulfur can also be the cause. Deformities are commonly due to a potassium shortage. It is often not possible to take an exact anamnesis if there is any damage. Therefore, feed the tomato a complete fertilizer that contains all the minerals.

Burnt roots or leaf edges

The burnt roots and leaf edges are also a common result of overfeeding. However, the solar radiation plays no role here. Due to a permanently increased nutrient concentration, the plant continuously loses liquid. This lack of water is reflected in burns on the roots and leaves. In this case, too, increased water intake is essential. However, parts of plants that have already been burnt cannot be restored.

Organic fertilizers for fertilizing tomatoes

nettle manure

Nettle slurry has been used as a natural tonic for many decades. The preparation of the brew is extremely simple and can be done in just a few steps.

• Chop 1 kilogram of fresh nettles or 200 grams of dried nettles
• Pour 10 liters of water over the nettles and stir vigorously
• optional: addition of rock flour to eliminate odors
• Close container airtight
• Stir daily for at least 10 to 14 days until no more bubbles appear
• Separate liquid from plant residues using a sieve

Before using the liquid manure, it must be diluted in a ratio of 1:10. The resulting mixture can then be distributed generously around the tomatoes every four weeks.

compost

Compost is also one of the most natural fertilizers.

In addition to lawn and shoot cuttings, withered plants and plant remains can also be heaped up in the compost. The decomposition processes produce a nutrient-rich humus soil over time.

In order to get the greatest possible effect from the humus, it is advisable to fertilize a large area in autumn. For this purpose the compost evenly distributed in the bed. It is then incorporated into the existing soil. The microorganisms and nutrients contained can thus spread penetratingly until planting next year. Optionally, additional compost can be added in the spring.

worm tea

Also known as compost tea, worm tea is a by-product of making compost with worms. However, its use is not nearly as widespread as that of humus. This is mainly due to the much more difficult extraction. When the compost is stored in a commercial composting area, the liquid continuously seeps into the ground. To catch them, a special worm composter needed. The materials to be composted are filled into this. The resulting liquid is then collected in the lower area of ​​the container. With the help of a tap, it can be easily tapped off for use.

Due to the high nutrient density, fertilizing every four weeks is also recommended for the worm tea. Diluting the tea with additional water allows the liquid to be stretched. In this state, fertilization is also possible every two weeks.

Organic (liquid) fertilizer

Organic fertilizers can also be purchased ready-made in stores. The nutrients are presented either in powder form, granulated or liquid. As a rule, however, the compositions differ only slightly from one another.

While solid variations have to be worked into the soil, adding liquid fertilizers to the irrigation water is sufficient. In terms of tradability, liquid fertilizers in particular are extremely popular. Precise information on the dosage is noted on the packaging. As a rule, regular fertilization every one to two weeks is recommended due to the short periods of action.

Supplementary fertilizer from home remedies

Basically, the aforementioned complete fertilizers offer the tomato plants all the important nutrients. However, an increased need for minerals can arise for various reasons. Examples are unfavorable site conditions or a disease.

In these cases, individual substances can be supplied inexpensively with the help of home remedies. It is important to note, however, that the following home remedies are only suitable as supplements. Sole fertilization is strongly discouraged.

• eggshell: contains calcium and magnesium
• coffee grounds: contains potassium and phosphorus
• Milk: contains calcium and phosphorus
• baking soda: contains sodium

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