Guest Author - Susan Taylor
Clean up your plants
Use the cooler winter months to spend some time with your plants. Clean off leaves with lemon juice to remove all that messy build up of fertilizer or minerals on the leaves. Remove dead sheaths and sarongs to reduce the number of places that insects have to hide. This attention will really pay off in the long run with plants which have been taken care of.
Check for pests
Make sure that you do a thorough and periodic check of your plants for insects. Warm humid conditions inside or in a greenhouse will attract all kind so of predators. Snails, slugs, ants and other insects will find the conditions as nice as your orchids do. Watch for signs of scale and mealy bugs -- any kind of white fuzzy mass -- or eaten areas on your plants. Spray with a mixture of soap and water and apply Diatomaceous Earth for slugs and snails.
Check for molds
As you clean off your plants (both sides of the leaves) make sure that you keep an eye out for any kind of moldy looking areas. For some reason, as the temperatures stay cooler, molds will start showing up as dark areas usually on the lower surface of the leaf. Spray with Physan or Consan to protect any open surfaces from your cleanup and to reduce the growth of any unwelcome molds or rots.
Practice good sanitation
When working with your plants, be sure to wash your hands between plants and clean off your tools in order to eliminate the possibility of passing viruses between plants. An alternative to this constant hand washing is to use those thin latex gloves so common in doctors offices -- one pair per plant. I often use these when applying any kind of insecticide since it can be absorbed into the skin. The gloves will provide protection for both you and your plants.
Increase your air circulation
Now is the time to add air circulation to your growing area. It is imperative to keep the air circulating around your plants, both to keep molds from forming and to keep the air from getting too hot or too cold in any particular spot. In a windowsill area, those plants nearest the windows can become chilled even wh en the temperature in the rest of the house is in the 70s. Moving the air will help keep the temperature in any particular place more at an average. Use a small fan which attaches to a curtain rod or other stable object or a small box fan to keep that air moving well.
Check your light levels
Since the sun moves with the seasons it is possible that the perfect place for orchids during the summer gets little or no light during the winter months. This can be important because of the reduced number of sunlight hours as well as the position of the sun. It might be necessary to provide artifical light for a couple of hours in the evening to give your plants enough light to grow and prepare to flower.