• Christmas cacti need special care now to produce flowers in December. Buds will form when temperatures are between 50° and 60°F, or if the plant is exposed to at least 13 hours of complete darkness each night. Putting them in a spare room is well worth the extra effort it may take for the spectacular display of blooms that is sure to follow.
• Plant fresh grapefruit or orange seeds in a well-drained, sandy soil, and you will soon produce attractive, green-leaved plants.
• Cacti and other succulents, such as jade plants and sedums, do best in a sunny south or west window during the winter. They can tolerate cool temperatures, but you may want to move more tender foliage plants away from cold windows.
• If you use plastic pots instead of clay ones for your house plants, you won’t have to water as much or as often. Clay absorbs soil moisture, minimizing the dangers of overwatering, but it does require that you be more attentive to watering chores. To reduce water loss from clay pots, nest them in decorative glazed or plastic planters.
• When you cover up the furniture with drop cloth to give your interior a new coat of paint, move your interior gardens to another room for several days. Even the very low levels of mercury contained in wall paint to retard mildew can produce enough toxic fumes to severely hurt such sensitive plants as Dieffenbachia and weeping fig.
• Do not pot cacti in plain sand, or they won’t grow. They may survive, but that is all, because sand contains no nutrients. Use a mixture of one part sand and one part soil. Most desert cacti need a bit of lime or crushed eggshells in the potting soil. If you can’t get sand for your cacti, substitute bird gravel, available at pet stores.
• House plant growth slows as the days get shorter and light intensity is reduced. This means that they will need less frequent watering and fertilizing until next spring. Too much of either in the winter months can cause weak growth.
• House plants need to come indoors before they are damaged by the cold (below 50°F). First be sure to check them for pests. Rinse the plants’ leaves, and soak pots in water for 15 to 20 minutes to drown most soil-dwelling pests.
• For healthy house plants, always use pots that have a drainage hole. If you have an attractive pot without a hole, either drill one in it, or pot your plant in a smaller ordinary pot and set it on top of some pebbles inside the pretty one.
• Poinsettias are short-day plants and need special treatment to have them bloom for Christmas. Keep the plants in an area where night temperatures are around 60°F and protect from artificial light at night. Control day length by placing the plant in a dark area at 5 pm and removing it at 8 am. Do this for 11 weeks. Start now for Christmas blooms. In addition to this treatment, be sure to provide them with adequate water, fertilizer, and night temperatures to get a healthy display of color for the holidays.
• For easy, small-scale propagation of African violets and other tender cuttings, soak peat pellets, squeeze well to remove excess moisture, and set cuttings in the top of the pellet. Place in a small plastic bag with a stick or label inside to keep the plastic from touching the cutting. Seal the bag fairly tightly. Place it in bright light, but not direct sun. When a good mass of roots has formed, pot up the pellet.
Diane Relf, Extension Specialist, Environmental Horticulture
Monthly Tips have been prepared since 1986 by various staff of the Office of Consumer Horticulture including Ellen Bennett, Michelle Buckstrup, Susan Day, Susan DeBolt, Sharon Dendy, Kate Dobbs, Sheri Dom, David Gravell, Virginia Nathan, Jenny Shuster, Ellen Silva, and Ruth Sorenson. Resource material for the development of this information includes the Virginia Master Gardener Handbook; Extension Publications and newsletters from VCE, numerous other states, and the USDA; and an extensive library of over 900 books, magazines and journals. Project funded by The Virginia Gardener Newsletter subscription fees. Diane Relf, Project Director and Content Specialist.