If you want healthy and thriving plants, you’ve got to use the right fertilizer. Although it can be challenging to understand the different types of fertilizers and how they benefit your houseplants, you’re not alone. 

In this article, we’ll review the different types of fertilizers and how to select the best one for your plant’s needs.

First, we’ll look at the three fundamental macronutrients found in fertilizers, typified by the NPK acronym. 

Then, we’ll look at the reason and benefits of using fertilizer and the different types for your indoor plants. 

What does N-P-K stand for and what do the numbers mean?

Fertilizers should consist of three key macronutrients: nitrogen, phosphorus, and potassium–referred to as NPK. These are essential for plant growth, but in different ways. Nitrogen helps with leaf growth, so if your plant is looking a little sad and yellow, it might be nitrogen deficient. Phosphorus aids in the development of strong roots and flowers and is therefore important for blooming plants. Potassium helps the plant develop sturdy stems and is essential for all around healthy growth.

The three numbers on a fertilizer label indicate the percentage of each macronutrient by weight in the product. The first number is the percentage of nitrogen (N), the second number is the percentage of phosphorus (P), and the third number is the percentage potassium (K). So, a 10-10-10 fertilizer has 10% nitrogen, 10% phosphorus, and 10% potassium.

The reason to fertilize indoor plants 

Indoor plants need fertilizer because they’re not getting the nutrients they need from the soil. Unlike outdoor plants, which can access nutrients from the ground, indoor plants are limited to the nutrients in their potting mix.

Over time, these nutrients can become depleted, leading to unhealthy plants. Fertilizer provides a way to replenish the nutrients in the potting mix and keep your plants healthy.

The benefits of using fertilizer for your houseplants

Fertilizer helps your plants grow by providing them with the nutrients they need. When used correctly, fertilizer can result in:

• Improved plant growth
• Stronger roots
• More flowers
• Better stress tolerance

The three main types of fertilizers for indoor plants

Granular

Granular fertilizers are spread on top of and throughout the soil and provide nutrients when the plant is watered.  This type of fertilizer is best for plants that need a steady supply of nutrients over a long period of time.

A disadvantage of granular fertilizer is it can be difficult to control the amount of nutrients that your plant is getting. 

Liquid 

Liquid fertilizers are dissolved in water and then applied to the plant. They are absorbed quickly and work well for plants that need a quick nutrient boost.

One drawback of liquid fertilizer is that it can be easy to overfertilize your plant and cause damage to it.

Slow-release 

Slow-release fertilizers are made up of pellets that dissolve slowly over time, releasing nutrients into the soil as they break down. This type of fertilizer also work well for plants requiring a regular supply of nutrients over a long period of time.

The disadvantage arises if you have a plant in need of nutrients, it might not get the immediate boost it requires from a slow-release fertilizer.

How to apply fertilizer to your indoor plants

The method of application will depend on the type of fertilizer you are using.

Granular fertilizer should be applied to the top and throughout the soil and then watered completely. Ensure that the water drains away to avoid root rot.

Liquid fertilizer has to be diluted in water; if applying to the roots, place it in the soil and if applying to the leaves, use a spray bottle.

Slow-release fertilizer is to be applied as follows: create a hole in the potting mix with your fingers, insert the pellet in the hole, and then cover with potting mix. Water as usual.

When applying fertilizer, be sure to follow the instructions on the package carefully, as over-fertilizing can damage your plants.

How often should you fertilize houseplants?

The frequency with which you fertilize your houseplants will depend on a few factors, including the type of fertilizer you’re using and the needs of your plant.

In general, liquid fertilizers can be applied every two weeks, while slow-release and organic fertilizers can be applied every four to six weeks. Once again, follow the instructions on the fertilizer package for the best results.

When should you fertilize indoor plants?

The best time to fertilize your indoor plants is in the spring and summer months when they are growing. Depending on the plant, avoid or reduce fertilizing during the fall and winter when most plants are dormant.

Is it possible to over-fertilize your houseplants?

Yes, it’s possible to over-fertilize your plants. This can happen if you apply too much fertilizer or if you fertilize too often. Over-fertilization can lead to burned or yellowed leaves, stunted growth, and other problems.

If you think you’ve over-fertilized your plant, flush the potting mix with water to remove excess fertilizer. Then, cut back on the amount of fertilizer you’re using or the frequency with which you apply it.

Can you use the same fertilizer indoors that you use for outdoor plants?

No, you should not use the same fertilizer indoors that you use for your outdoor plants. Indoor and outdoor plants have different nutrient needs, so it’s best to use a fertilizer that’s specifically designed for indoor plants.

What should you look for when buying indoor fertilizer?

When buying indoor fertilizer, you should look for a product that’s specifically designed for indoor plants. You should also consider the needs of your plant and choose a fertilizer accordingly.

For example, if your plant is lacking in nitrogen, as evidenced by yellowing leaves for instance, look for a fertilizer with a high nitrogen content.

Conclusion

By now, you should have a good understanding of the different types of fertilizers available for your houseplants and how to apply them. Fertilizing your plants provides them with essential nutrients that help them grow healthy and strong. By understanding the different types of fertilizers available and how to apply them, you can keep your indoor plants looking beautiful all year long.

So go ahead and give your plants a little TLC by fertilizing them regularly!