Like all living things, plants need food to grow and to obtain energy for their metabolism. They absorb three of the most important nutrients, namely carbon, hydrogen and oxygen, as gases from the air or as components of water from the soil. But in addition, they need a whole range of other nutrients that we have to supply to them.
How should you fertilize a vegetable garden?
In order to optimally fertilize a vegetable garden, you should divide plants into heavy feeders, medium feeders and weak feeders and use organic or organo-mineral complete fertilizers according to the dosage instructions. It is also advisable to lime the garden soil regularly and have it examined by a specialist laboratory occasionally.
The most important rules when fertilizing
Almost all plant nutrients are in the soil, but by harvesting and removing plant residues, the gardener also removes the nutrients bound in them, so that the soil reserves are gradually depleted. The purpose of fertilization is therefore to continually replenish the soil reserves.
Adjust fertilization to the plant species
Basically, garden plants (and therefore also vegetable plants) are divided into heavy feeders, medium feeders and weak feeders. This distinction tells you how many nutrients a plant needs. Preferably use organic or organic-mineral complete fertilizers prepared according to the manufacturer's dosage instructions for heavy eaters, half the dose for medium eaters and a quarter of the dose for light eaters. Avoid over-fertilizing the soil, because on the one hand phosphates etc. accumulate in the soil - and on the other hand, over-fertilization as well as malnutrition can lead to growth disorders and increased susceptibility to diseases and pest infestation. In addition, typical over-fertilization diseases can occur, which ultimately reduce the yield.
Which vegetables need how much fertilizer?
The following table shows you which vegetables require a lot of fertilizer and which require little. If you fertilize your garden with compost, the additional complete fertilizer used for heavy and medium feeders should be reduced by half. In this case, weak eaters no longer receive any complete fertilizer. If you regularly spread two to three liters of compost per square meter in spring, you can also forego the complete fertilizer altogether and instead apply up to 150 grams of horn shavings (€32.00 at Amazon) per square meter for heavy feeders and up to 100 grams for medium feeders.
| Heavy eaters | Middle eaters | Weak eater |
|---|---|---|
| Cucumber | Chicory | bush bean |
| Potato | Chinese cabbage | Pea |
| cabbage | Strawberry | Lamb lettuce |
| Pumpkin | Fennel | Herbs |
| Peppers | Carrots | cress |
| Rhubarb | garlic | Purslane |
| Celery | Kohlrabi | Radish |
| Tomato | Chard | Turnip |
| Zucchini | Parsnip | |
| sweetcorn | parsley | |
| Leek | ||
| Radish | ||
| Beetroot | ||
| Salads | ||
| Spinach |
Lime the vegetable garden properly
Very few gardeners know the exact pH value of their garden soil. Nevertheless, the soil should be limed occasionally, and this happens according to this scheme if compost is used regularly: Every two to three years in early autumn, spread a slow-acting lime fertilizer according to the manufacturer's dosage instructions. If in doubt, you should use a slightly lower dosage.
Have your garden soil examined
Basically, it is a good idea to have the soil examined by a specialist laboratory about every four years and then get tips for fertilizing in a way that is suitable for the soil. A soil test is due at the latest when the vegetable plants often show growth disorders or whitening of the leaves or even crop failures occur with incomprehensible causes.
Tip
Homemade plant manure made from nettles and comfrey are tried and tested organic liquid fertilizers that quickly supply the plants with nitrogen and potash. Both also contain other nutrients and plant-strengthening compounds such as silica from nettle.