When it comes to herbs, many hobby gardeners think of Mediterranean plants that do not require any nutrients. However, there are popular culinary herbs that value nutrient supply. The frequency of fertilization is also low for these plants.
How should you properly fertilize herbs?
To properly fertilize herbs, you should fertilize nutrient-loving plants once or twice a year and plants in poor locations every two to three years. Use special herbal fertilizers, compost or coffee grounds to provide nitrogen, phosphorus and potassium. Watch out for deficiency symptoms to keep the herbs he althy.
Herbs and their nutritional requirements
Culinary herbs, which are originally native to the Mediterranean region, grow on dry, sandy soils. Plants such as lavender, thyme and rosemary specialize in poor locations and do not need to be fertilized every year. Mint, basil and tarragon are among the species that thrive in shadier conditions and have higher water requirements. They value regular fertilization.
Deficiencies
In addition to the main nutrients, herbs require trace elements in low concentrations. If these are missing in the fertilizer, growth problems will occur. A lack of iron manifests itself in yellowish leaf discoloration. Plants in partially shaded locations such as mint are susceptible to iron deficiency. If the leaves become discolored, a copper deficiency may also be an issue. Basil or parsley often have a tendency to curl the leaf edges, which indicates a boron deficiency.
Fertilizing tips
Herbs are sold in a nutrient-rich substrate to keep them looking fresh and crunchy. In the first six to eight weeks, the plants do not need any additional fertilization. This well-intentioned care measure would lead to over-fertilization. During further cultivation, the nutrient supply requires little attention.
In general:
- first application of fertilizer in spring
- Fertilize nutrient-loving plants once or twice a year
- Provide plants in poor locations with nutrients every two to three years
Dosage
It is better to fertilize more often in lower concentrations to avoid oversupply. Herbs with a high nutrient requirement such as lemon verbena or chives can receive a little more fertilizer. This also applies to sandy soils, where nutrients are quickly washed out.
The right fertilizer
There are special herbal fertilizers available in stores (€6.00 on Amazon) which should be tailored to the needs of the plants. Nitrogen is crucial for he althy growth. Phosphorus promotes root formation and supports the development of flowers and fruits. Potassium strengthens plant tissue and makes it more resilient.
Compost
The substrate is a perfect fertilizer because it contains all the important nutrients and trace elements. Compost is suitable for medium to heavy feeders such as chervil, lovage or tarragon. Pay attention to the quality of the compost soil. It should be dark in color, loose, fresh and not emit any unpleasant odors.
Coffee grounds
Many herbs are grateful to be fertilized with leftovers from the coffee filter. Coffee grounds as a fertilizer supply the plants with nitrogen, phosphorus and potassium, although the powder is a rather weak source of nutrients. The pH value of the substrate fluctuates when coffee is added. Therefore, you should only fertilize herb plants that thrive in both slightly acidic and moderately alkaline substrates. These plants include some species that prefer partially shaded and moist locations.
