Tropical House Plant Care – Fertilizing Your House Plants

Your plants basically need two types of nourishment to survive: water and minerals. They get minerals by absorbing them from the damp soil through their roots. Outdoor plants can often gather all the minerals they need from their surroundings by themselves. However, houseplant care requires more careful attention from the gardener, since the nutrients available from the soil in a pot are limited.

What are those three numbers on the bag of fertilizer?

The key elements required for plants are Nitrogen (N), Phosphorus (P), and Potassium (K). A fertilizer bag shows the percentages of these three nutrients as three numbers, always given in the same order. An example: an 18-6-12 label means that the bag contains 18% nitrogen, 6% phosphorus, and 12% potassium, usually in the form of nitrates, phosphates, and potassium salts. Other nutrients are also needed, but their required amounts are much lower.

How much of each element should I use for my plants?

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 is the function of each of the primary nutrients?

This is a subject of continuing research by scientists. To oversimplify a bit, we can say that leafy plants need lots of nitrogen, whereas flowering varieties require more phosphorus. Potassium is useful in combating plant diseases, and is also needed by fruit-bearing plants as an aid in transporting other minerals through plant tissue.

How do I know if my plant is getting the right amount of these foods?

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 apply the fertilizer, and how often do I do it?

Personally, I prefer fertilizers that are dissolved in water, as this method is less likely to result in over-fertilization. I mix the fertilizer according to package directions, and then apply it by thoroughly watering the plant, until it flows out of the drainage holes in the bottom of the pot. I find that doing this about every two months is usually just about right.

By being careful in fertilizing houseplants, you can make sure that they not only survive, but thrive. And be sure to take advantage of your plant-supplier. He should be happy to give you advice on how to keep your tropical houseplants healthy.