Houseplants need humidity to be happy over the holidays even though they are mostly hibernating.
Many of the plants we bring inside to protect from freezing, go through a dormancy period because of shorter daylight hours. For example, Begonias, Philodendrons, Ficus and Norfolk pines are dormant in the winter; they prefer to stay dry.
Cut back on watering and fertilizer. Water when the pot’s soil is totally dry and use one-fourth the recommended strength fertilizer in that water.
The best method is soaking. Fill a dishpan or the kitchen sink with a few inches of water and soak the pots until the top of the soil is moist. Then, set the pots aside to drain. When water stops coming out of the bottom of the pot, return it to its saucer. Never allow houseplants to sit in a saucer containing water.
Exceptions include ferns and potted citrus which need consistently moist soil, even in the winter. Most houseplants appreciate being misted or dusted with a damp cloth to keep their leaves moistened.
Lucky bamboo is not bamboo; it is a Dracaena. Another popular Dracaeana is Corn Plant. They need light but no sun, prefer filtered, not tap, water and cannot tolerate their roots sitting in water.
To keep your houseplants green, provide supplemental light. One 40-watt cool bulb plus one 40-watt warm bulb in a shop light is recommended.
Deciduous plants that drop their leaves in the winter can skip water entirely over their dormant period. But if a houseplant starts dropping its leaves it can be a sign of over watering or dramatic temperature changes.
If African Violets are watered with cold water in the winter their leaves will get white spots. Begonias enter winter dormancy and need little water.
Protect plants from cold windowsills, cold air coming into the garage or near doors.
Blowing heat from the furnace can cause plants to dry out. Heated homes have ten to twenty percent humidity and plants are accustomed to forty percent. Brown leaf tips or insect problems can be a sign of being too dry.
White cottony, fluffy masses on houseplants are a sign of mealy bugs. They will move from plant to plant so as soon as you see yellowing leaves, move that plant away from the others. Dip a cotton swab or q-tip in alcohol and touch the places where you see the mealy bugs. Let the alcohol do its job, then rinse the plant.
If houseplants have a spider web appearance and the leaves are changing color, it probably has spider mites. Wash off the plant gently in the kitchen sink or shower. Mites thrive in dry winter homes and on plants that are not receiving enough water.
If the rinsing is ineffective and the spider webs return, use Safer soap spray or other products safe for home use.
Your Amaryllis or Hippeastrum wants to be watered thoroughly once. Then, water again when growth starts. When the flower bud is visible, keep the soil moist and fertilize once a month. They need 12-hours of bright light.
Houseplant care is covered in Oklahoma State University Fact Sheet HLA-6411-4, available at http://pods.dasnr.okstate.edu/docushare/dsweb/Get/Document-3231/F-6411web.pdf if you need more information.