The Correct Use of Fertilizer for Your Plants

This is another continuation in the series of how to grow and maintain your plants by working with the plant's metabolism in order to allow them to grow into large lush specimens. In the manual I wrote, "How to be Successful with Houseplants From the Plant's Perspective" I described in detail all the guide lines I use to maintain all the plants in the greenhouses I have managed, as well as the plants in my home. I have devised these guide lines that work with the plant's metabolism to help anyone who wishes to grow large lush specimens from small potted plants. All those who have followed these guide lines have been successful in understanding how a plant uses the environment to sustain itself. And working with this understanding is the basis for growing any plant, inside or out.

Fertilizers give the plant the nutrients necessary for it to build new cells in order to grow. They use these minerals found in the soil to build its different parts, and using different fertilizers to direct that growth is the key to allowing the plant to develop into a large healthy specimen. On each container of fertilizer is a series of numbers that represent the analysis of the percentage of nitrogen, the first number, phosphorous, the second number, and potassium, the third number, In the US, this analysis is dictated by law and must appear on the label of every container of fertilizer sold.

So what exactly does this analysis mean? It is the percentage of each of the nutrients. Nitrogen is used by the plant to build leaves and stems, phosphorous is used to build a healthy root system, and potassium is used to help the plant use the minerals and to aid the plant in developing pollinated flowers into fruits and vegetables. This, of course, is a very simple version of how the plant uses the fertilizers, but it gives you an idea as to how the plant uses these nutrients to grow.

In plants, the growth is divided into 2/3 top growth and 1/3 bottom growth (the root system). This ratio is found in all of nature, including people. Our arms, legs, facial features,etc. all grow according to a programed ratio in respect to its different parts. If this ratio is out of balance, the person may look awkward. If you study the ratio of a person that is considered beautiful, you would see that all parts are in perfect balance to each other. In the same way, a plant that grows in proportion is beautiful in comparison to one that has more root system and less top growth. It just looks funny. When we plant a huge container with annuals for decorating the steps or patio for the summer, we only put in a few plants to begin with so that they will have room to grow. At first, the planter looks funny because there is too much container and not enough plant. But, by the end of the summer, the plants have filled in and hang over the sides and the planter looks beautiful. If you study the proportion of top growth to root system, the 2/3 top to 1/3 ratio is present.

The same holds for the potted plants in our homes. If you are growing a plant that does not flower, such as a philodendron or pothos, you want the plant to have a large lush top growth with less root system or the plant will look awkward. Using a fertilizer with a higher first number in the analysis will direct the plant to build more leaves and stems (runners) than roots. In the same way, using a fertilizer with a higher middle number, such as 15-30-15 for a cyclamen or African violet, will direct to plant to build a stronger root system that will encourage the plant to flower rather that build a large leaf system and few flowers.

A potted plant flowers because it feels life-threatened and develops flowers in order to make seeds that will propagate the species. Flowering is the first step in a plant's propagation to reproduce itself. When the roots of the plant fill the pot, the plant goes into a flowering mode. Therefore, the use of a fertilizer higher in the middle number, such as 10-30-20, will direct the plant into developing roots that will fill the pot and send the plant into its flowering mode. This is exactly how growers get their plants to flower sooner so they can be sold to retailers for our purchase. The timing of the fertilizer is important for the plants to reach their flowering mode at the times when they are purchased for the holidays, IE: Poinsettias and Easter Lilies, to name a few.

Nitrogen and potassium are the two nutrients used most in directing the growth of plants. Potassium is also present and is used along with the all the nutrients according to the plant's needs.

It is important to remember to use a fertilizer with a higher first number, IE: 5-1-1 as listed on the containers of a fish emulsions fertilizer, to promote that healthy lush top growth for plants that normally do not flower. Depending on quickly you want to plant to grow will dictate how often you use the fertilizer as well as its concentration level in the water. By using a low concentration of fertilizer every time you water during the active growing season, you will promote the greatest amount of growth in the shortest amount of time. In the same way, if you want to sustain the size of a large plant and do not want it to outgrow its space, using a low concentration only once a month will help to maintain that size. The more fertilizer and the greater the frequency given, the more the plant will grow. Remember that a plant uses the nutrients in the soil and those nutrients need to be replaced by fertilizing.

Now that you know how to use fertilizers to direct growth, here is a list of when to use them and when to just let the plant do its own thing.

-Never use fertilizers on a newly purchased or transplanted plant because it is in shock and the plant is in a healing mode. The use of chemical fertilizers at these times can be very harmful.
-Never fertilize during the winter months when the daylight is the shortest as the plant needs a lot of light to use the nutrients in the soil. Winter is when most houseplants are resting and the buildup of chemicals in the soil can kill a plant.
-Never fertilize a plant that has a very dry soil. The fertilizer will wash over the root system as the water runs out of the soil. This can burn the roots which will show as a chemical burn on leaves, usually as brown spots ringed with yellow. Always water the soil to hydrate it before fertilizing.
-Only use fertilizers during the active growing period when new growth appears on the plant.

If used correctly, fertilizers will allow you to grow small plants into large, lush specimens that will add beauty and elegance to your home.