top of page
  • Thrive & Co

Tropical House Plant Care - Part III - Fertilizing Your Houseplants

By David Broadhead, Ph.D.

In order to survive, your houseplants need two kinds of nourishment. We discussed one of these, water, in Part II of this series. They also need minerals. When a plant is outdoors, it can usually get enough minerals from its surroundings all by itself. But houseplants need more attention - the nutrients available to them indoors must be provided by the gardener.

What do those numbers on the fertilizer bag mean?

Most fertilizers have the three minerals necessary for plants: Nitrogen (N), Phosphorus (P), and Potassium (K). The numbers on the bag represent the percentages of these three nutrients. A fertilizer labelled 20-10-15 has 20% nitrogen, 10% phosphorus, and 15% potassium. These are not the only elements that a plant needs, but other elements are required in much lower quantities.

How much of each mineral does my plant need?

This of course depends on what type of plant you are fertilizing. It is very important not to give your plant too much or too little food. This is a decision that must be made for each individual plant. You should carefully read both the label that came with your plant if there is one, and the label on the bag of fertilizer. If you're still not sure, ask the person at the plant store for advice.

What does each of the minerals do?

This topic is continually being researched by scientists. For the purposes of gardening, we can say that phosphorus is needed in greater amounts for flowering plants, while leafy plants like plenty of nitrogen. Potassium is particularly required for plants that bear fruit, since it helps to carry other nutrients through the plant tissues.

What are the symptoms of poor feeding?

Insufficient fertilization can cause the plant leaves to turn pale, or not to grow as large as they should. This can be remedied by using a fertilizer solution, so that the plant can absorb nutrients faster. If plants are over-fertilized, the leaves may wilt or begin to turn brown at the tips. In this case, you should thoroughly soak the plant in water to rinse the excess minerals away.

How do I fertilize my plants, and how often?

My personal preference is to use "liquid" fertilizers, since that makes it more difficult to over-fertilize. Dry fertilizer is dissolved in water using the directions given on the package. Then the plants are soaked by pouring the solution into the pot until it begins to flow out the holes in the bottom. I do this every two months - a bit more frequently during the blooming season.

If you use care in feeding your house plants, they will not only stay alive, they'll become luxuriant. And don't forget to ask for advice if you're having difficulties. Your plant store should be happy to help a good customer.

Do you need more advice on tropical houseplant care? Visit the Professor's website on tropical houseplants, where you can get help with your plants. I also have lots of beautiful photos, and some cool videos too.

Article Source: Tropical House Plant Care - Part III - Fertilizing Your Houseplants

Thrive & Co participates in the Amazon Services, LLC Associates program, and affiliate advertising program designed to provide a means for us to earn fees by linking to and affiliate sites.

bottom of page