Giving fertilizer to houseplants is one of the most difficult measures and one where the most common mistakes occur. To make matters worse, each type of plant has its own individual nutrient requirements. Nevertheless, there are some strategies that you can use as a guide. Tips and tricks can be found in this article.
How should houseplants be properly fertilized?
Fertilizing houseplants correctly means choosing the right time, the right type of fertilizer and an appropriate dosage. Pay attention to the growth phases of the plant and its individual nutrient requirements. Alternative, organic fertilizers such as coffee grounds or eggshells can also be used.
The right time
No houseplant can survive without nutrients. However, how quickly it utilizes the available minerals from the earth depends on the individual. So-called heavy feeders have particularly high needs and are dependent on frequent fertilization. Slow-growing cacti, on the other hand, also develop in potting soil that is not fertilized for years. A general recommendation for the intervals between two fertilizer applications cannot therefore be given. In principle, the substrate should be refreshed frequently or the houseplant should be repotted without adding fertilizer. For detailed information, please contact your tree nursery or see the care instructions on the plant label.
Observe growth phases and rest periods
Most houseplants withdraw their energy indoors in winter and do not develop new shoots. Accordingly, their nutrient requirements decrease. Stop adding fertilizer as soon as your houseplant moves into its winter quarters. From March you can continue as usual.
Note: Only houseplants that bloom in winter (e.g. the poinsettia) still need to be supplied with nutrients.
Choice of fertilizer
Fertilizers (€6.00 on Amazon) are available in various dosage forms from specialist retailers:
- Granules
- Liquid fertilizer
- Chopsticks
- or powder
Which option you choose is entirely up to you. The composition of the nutrients is much more important. Here you have to address the individual needs of the respective plant species. The most important nutrients are:
- Potassium (for strong roots)
- Phosphorus (for lush flowering)
- and nitrogen
Alternatives
Fertilizer from specialist retailers is too expensive or uncertain for you? Enrich the substrate with your own resources. Organic material could, for example, consist of
- Coffee grounds
- Compost
- Wood ash
- or eggshells
exist.
Coffee grounds are ideal for plants that prefer acidic soil. However, since it changes the pH value of the soil, it is not suitable as a permanent alternative and should only be used occasionally.
Eggshells have the opposite effect. They contain a lot of lime and thus raise the pH value of the earth. Wood ash is also rich in lime and also provides valuable potassium. If your houseplants suffer from fungal diseases or rot, the ash can help them recover.
Dosage
Over-fertilizing houseplants is even more harmful than having too few minerals in the soil. Too much of a good thing can even cause leaf diseases that ultimately lead to the death of the plant. Succulents and orchids are particularly sensitive due to their low nutrient requirements. It is best to always follow the information on the plant label exactly. Here is how often you should fertilize your plant.