How to prep your indoor plants for winter

Gardening has a pendulum element. Canadians don’t suddenly garden outdoors, then indoors overnight. Perhaps you will rake leaves one day and repot your Hoya indoors the next and then plant a tree the next day.

Your indoor tropical plants go through many changes, much like outdoor plants.

The gradual reduction in the length of the day is part of the system that causes a multitude of changes for indoor plants. The sunlight is less intense every day as our earth tilts further from the sun. The heat of your home is turned on to keep people cozy, dry the air, and devastate some tropical plants. Certain insects come to life.

What should I do? Our advice:

1. Reduce pouring. Almost all tropical plants require less water from now until March because they grow slowly – if at all.

Test the water requirement by pressing your finger into the soil up to the second knuckle. When the soil is cool, it will be moist enough for most plants. When it’s two to three inches dried, it’s time for a drink.

Let the water flow through the soil into a saucer or your sink and let the excess water drain away. No tropics likes to sit in the water for long; it is an invitation to root rot.

2. Fertilizer. Often times, when a plant is performing poorly, we are tempted to reach for fertilizer to repair it. Resist this impulse.

The plant is talking to you, and it is not saying it is hungry. It is more than likely that it needs more sunlight or has an insect infestation. Or maybe you over-watered it, in which case read # 1 again.

The hibiscus that bloomed all summer will recover from blooming as the day length is shortened.

3. Insect infestation. The three main enemies of tropical plants at this time of year are mealybugs, fungus gnats and spider mites. For treatment we recommend:

  • Mealy bugs. Small, crawling insects that suck the good out of tender stems and leaves. They are about an inch long and look like flattened cotton pads. You can crush them with your fingers if you have the stomach for it. Or brush them with undiluted rubbing alcohol with a small artist’s brush. In the case of a large system, this will take some time.
  • Mushroom mosquitoes make themselves felt when reading the newspaper. They love to bomb the newspaper themselves (sorry e-readers). The other way to spot these tiny “fruit flies” is to disrupt the surface of the ground by scratching with a fork. When a cloud of small, black flies descends, voila! The solution is to reduce watering far, as mushroom mosquitoes are only interested in eating mushrooms that grow in moist soil. Starve the fungus, starve the mosquitoes. Keep scraping the earth weekly until they go away.
  • Spider mites. These creatures are tough. Small red beetles the size of the head of a pin. When the leaves of your plants turn yellow, you can spot spider mites by placing white paper under the plant while you shake it. The mites fall on the paper and contrast with it. The best solution is to wipe the leaves of the plant every week with a clean, soft cloth soaked in insecticidal soap. If that doesn’t work, put the entire plant in a plastic bag, tie the top to protect it from overwatering, and put it in the shower for about five minutes. Mites hate moisture and love dry air. Do this weekly until you no longer spot the mites.

Reduce watering of houseplants from now until next March.

4th This is a tip for any indoor gardener. Our Canadian winters are long, so remember, house plants are tropical. Depending on where you live, you are used to the rainforest or the desert. They did not originate in our homes. Be patient with them and expect some fallen and yellowed leaves as they acclimate to their winter environment indoors, especially if they lived outdoors for the summer.

Most tropical plants don’t thrive in our winter conditions – they exist. As indoor gardeners, we can only make this life more pleasant for them.

Mark and Ben Cullen are seasoned gardeners and contributors to the star. Follow Mark on Twitter: @ MarkCullen4


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