Indoor plant fertilizer should be understood to mean any mineral or organic substances that contain plant nutrients. Fertilizers aim to solve practical problems, whether it is to increase soil fertility, increase crop yields, or create a balance of nutrients. 

The indoor plant food system can be artificial or natural, depending on what is used as the source. By now, the market offers a variety of ready-made mineral-organic products that stimulate plant growth and development. As a rule, such fertilizers are synthetic.

The classic forms of fertilizers are based on three essential nutrients required by plants: nitrogen, potassium, and phosphorus. This means the main vectors of fertilizer chemistry development are focused on the synthesis of potassium, phosphorus, and nitrogen fertilizers.


Nitrogen is the primary building material of a plant and required for the average growth of vegetative mass. 

If the plant looks stunted, has low growth, and has pale leaves there is not enough nitrogen. 

Nitrogen deficiency also affects flowering because flowering and fruiting are inhibited in the absence of this nutrient. 

Where to get it: Nitrogen can be obtained from urea, sulfate, and ammonium nitrate, for example. 

When to Apply: As a rule, nitrogen fertilizers are applied to the soil in the spring or early summer in the amounts indicated on the individual packages. 


Phosphorus is key to the normal development and functioning of the root system, but the biological effect of phosphorus is not limited to this. 

This chemical element improves the ripening of fruits and seeds, increases the sugar content of fruits, plants’ frost resistance, and their resistance to diseases. 

Where to get it: Phosphorus can be obtained from phosphate meal, wood ash, one of the most common forms of monocalcium phosphate, or superphosphorus. Unlike nitrogen, phosphorus can rarely poison a plant. 

When to Apply: Phosphorus fertilizer is usually applied to the soil at the beginning of budding and flowering. 


Potassium helps improve the absorption of other micronutrients and optimize the timing of fruit ripening, if that’s a characteristic of your specific houseplant. 

Because houseplants are often annuals, potash fertilizers are vital for them to stimulate lush flowering. 

Where to get it: Potassium can be obtained from potassium sulfates and chlorides, potassium humate, and wood ash. 

When to Apply: Potassium fertilizer should also be applied in the early stages of budding, and the application process should be repeated 2-3 times. 

Fertilizing House Plants

When the need for the three key elements is no longer in doubt, it is essential to detail the nature of the fertilization procedures so you can replicate these fertilizing efforts again and again when fertilizing house plants.

It is also important to emphasize that indoor plants require fertilization if grown at home. Unlike outdoor organisms, house plants are more limited in resources and cannot effectively exchange with other ecosystem members through the soil. 

Potassium, phosphorus, and nitrogen fertilizers help maintain a balance of critical chemical elements in the plant, with each element targeted for use in specific practical applications. 

It is important to follow the dosage strictly, as deviations from it can lead to poor performance or poisoning from excess. At the same time, fertilizers should be applied in a balanced manner so that the plant gets access to all necessary nutrients at the same time.

Liquid Fertilizer For House Plants

One should pay attention to liquid variants. While garden and farm plants tend to perform better when fertilized with granular fertilizer, the best option is a liquid form of the nutrient for small houseplants. 

This can be a spray or bottled liquid that is watered into the soil near the roots. The dissolved form stimulates better absorption, and, as a result, the individual will notice the first results after just a few days. 

If the plant is just being set, it is imperative to fertilize it for the first time to give it the necessary impetus for increased development in its new environment. At the same time, there is no need to wait until the plant wilts or turns yellow to realize the need for a new fertilizing. 

The best strategy is to apply substances every few months. Keeping a fertilizer calendar to know when the plant was last fertilized is a good way to prevent poisoning due to over-fertilization. 

Natural Fertilizer for Indoor Plants

If the individual is interested in natural fertilization, however, he or she should look at a strategy for using organic household remnants. In particular, banana peels, coffee grounds, green tea, eggshells, and other household wastes can be used as natural fertilizers. 

The average American family produces 8 kilograms of garbage per day, much of which is inefficiently disposed of or incinerated. If they are recycled, the efficiency of home crop production increases, as the actual trash is used up for fertilizer. 

However, if garbage is discarded, the individual still can use other means of natural plant fertilization. For example, cow manure, algae, limestone, and compost also have high practical value for home crop production tasks. 

A key feature of using natural fertilizers is their biochemical effect on plants. More specifically, natural fertilizers release nutrients into the soil more slowly than ready-made synthetic substances. 

This is because the fertilizer components suitable for assimilation are not initially in the released state, so natural fertilizers require time to be absorbed by the root system. 

Moreover, it should be understood that the natural decomposition of organic debris releases byproducts that may emit an unpleasant odor. Consequently, the use of such fertilizers in the home can be complicated.