29 September 22, 2010

The nights are beginning to get cool.  Eventually, we will have a frost that will kill off any tender plants that have been left outside. Many of you will put your houseplants outside during the summer months. Before you bring those plants in for the cold months, you must make sure that you are not bringing any insect pests into your house along with the plants you are bringing into the house.

While the plants are outside, ladybugs and other predatory insects can keep the insects on your plants in check. When you bring the plants inside, there are not any of these predators to keep the bad insects in check. The warm, dry air indoors makes the bad insect population skyrocket. To prevent this problem, you should treat the plants for insects before you bring the plants into the house. Here is what you need to do.

There are insecticides that are called systemic insecticides. These insecticides are placed near the roots of the plant. The plant roots absorb the insecticide and carry the insecticide to all of the leaves and stems of the plant. As the insects feed on the plant, the insects are killed. Systemic insecticides will stay active in the plant up to 6 weeks. This type of protections helps to kill off any insects that hitch a ride into your home. Many insects lay eggs that take up to a few weeks to hatch. By using a systemic insecticide, the future generations of insects that hatch from those eggs can be controlled as well.

Systemic insecticides that are used on houseplants are in a granular form. The granules are spread on the surface of the soil and then the granules are watered. The watering releases the insecticide into the soil. This insecticide needs about a week to be absorbed and to be carried up to all parts of the plant.

You should apply this insecticide to your plants while the plants are outside. The reasons are that you need the week’s time to have the plants absorb the insecticide. The other reason is that the granules have a strong odor. You are better off having that smell outside and having the smell dissipate before you need to bring the plants indoors.

I have had a few questions about amaryllis bulbs and how to care for the plant now that it has been outside for the summer. Just like all bulbs, amaryllis flowers are created by the food that is stored in the bulb. Once the plant has finished flowering, most of the stored food has been used up. The plant will put out leaves to make food to store back in the bulb. You need to help this process out by fertilizing the soil. The roots take up the fertilizer in the soil and the leaves convert the fertilizer into food that is stored in the bulb. Once the bulb has stored sufficient food, the leaves will begin to turn yellow and the leaves eventually die. The bulb goes through a rest period of a month or more. While the bulb is in this resting state, you leave it in the pot and store the bulb in a cool and dark place. You generally don’t need to water the soil unless the soil gets very dry. Once the plant has finished its rest period, it can be taken up into the warm house and the flowering process can begin again. The problem some of you are having is that the leaves of the plant are still green. The most likely cause of this is that the plants have not made enough food. You need to increase the frequency of fertilizing the soil. If you use a diluted solution of fertilizer every time you water the plant, you will be providing the plant with enough fertilizer to get the job done. Next year, as soon as the flowers have gone by, you should begin the process of fertilizing every time you water. By doing this, the leaves will have made enough food and the leaves should die off by early summer.

Well, that’s all for this week. I’ll talk to you again next week.