Ask the Master Gardener: Cacti blooms in time for the holiday season
There are three holiday cacti: Thanksgiving, Christmas and Easter. They are in the same genus, but are different species and can be distinguished by the shape of their leaves.
Dear Master Gardener: My Christmas cactus is blooming right now, but some of the buds have fallen off. What could cause that to happen?
Answer: Your cactus is probably a Thanksgiving cactus, since it is blooming now. There are three holiday cacti: Thanksgiving, Christmas and Easter. They are in the same genus, but are different species and can be distinguished by the shape of their leaves. The Thanksgiving cactus has very pointed and claw-shaped projections on the edges of the leaves. The Christmas cactus has more scalloped or teardrop shaped leaf projections. The Easter cactus has rounded edges centralized on the leaf. They flower in response to the shortening of the days and cooler temperatures and bloom around the time of their holiday. The Thanksgiving and Christmas cactus may bloom again in spring, but probably won’t have as many blooms. They are all easy to grow as a houseplant and very long-lived. Keep them out of direct sunlight (near an east or west window is ideal) and in an area with cool nighttime temperatures. Fertilize them monthly June through August at half-strength and be careful not to overwater them. If your plant set flower buds and some have fallen off there could be several reasons: not enough or too much water, drafts or sudden changes in temperature, or it is receiving direct sunlight.
Dear Master Gardener: My corn plant (houseplant) has a bad case of aphids. How do I get rid of them? Also, why is it called corn plant?
Answer: Corn plant (Dracaena fragrans) is a popular houseplant in the asparagus family. It gets the name corn plant because it looks a lot like the tall, unbranched stem of a corn stalk. This plant grows with one or more canes and has a crown of leaves near the top of the cane, which to me gives it a palm tree appearance. It’s important to examine plants regularly for insects. Look for discolored leaves and/or honeydew (a shiny, sticky substance). Examine plants for aphids clustered on stems just below flower buds or newly opening leaf buds. If pests are detected, isolate the plant from others. Wash the leaves — I use a sponge or cloth with soapy water. You can also use cotton balls dipped in alcohol. Aphids can also be dislodged using a forceful spray of water. If your plant is large, you may need to do that in a shower. Insecticidal soap can be used if there is a large outbreak. I treat all my houseplants with a systemic insecticide. When a plant is heavily infested, it can be extremely difficult to totally get rid of them. In that case, you may want to cut your losses and toss the plant out.
Dear Master Gardener: One of my houseplants has mold growing on the soil. What should I do?
Answer: It’s not unusual to find mold growing on the soil of a houseplant. It is typically due to overwatering. When the soil of your houseplant stays consistently wet, it creates the perfect breeding ground for dormant mold spores to thrive. As a general rule, you should let the soil dry out between watering sessions. Keep in mind that most plants do not need as much water during the fall and winter months when they are not actively growing. Also, it’s imperative for houseplants to be in containers with drainage holes so the water drains out of the pot.
Dear Master Gardener: I’ve been told that to improve drainage, gravel or broken pieces of terra cotta should be put in the bottom of the container? Does it really help?
Answer: Plants definitely like good drainage and roots sitting in water can severely damage or kill a plant. According to Jeff Gillman, Ph.D., former horticulture professor at the University of Minnesota, water drainage is actually better if you just fill your container all the way with potting media. His advice, “Don’t use gravel or other nonabsorbent materials at the bottom of your container to increase drainage. If you feel you need better drainage simply buy better-draining media from your local garden center.” (The Truth about Garden Remedies, 2008). To keep the potting medium from escaping out the holes at the bottom of your container, place a piece of landscape fabric or an unbleached coffee filter on the bottom of your container before adding the potting soil.
Dear Master Gardener: Are there any unusual flowering houseplants I can try other than the typical ones?
Answer: Availability could be an issue, but following are three atypical flowering houseplants. Bird of Paradise is a relative of the banana and one of the most exotic, easy to grow potted plants. It not only has showy fans of blue-green leaves that are attractive all the time, but mature plants send up stalks topped with fascinating birdlike flowers that combine colors of golden orange and peacock blue during the warm seasons. Clivia, a member of the lily family, is easier to grow than an orchid and more unusual than an amaryllis. It has dark, evergreen, leathery leaves that provide a perfect backdrop for the dense clusters of orange flowers that appear. There are some yellow cultivars; however, they are quite rare and consequently expensive. A zebra plant is another option. Not only does it have dark leaves with striking, light-colored veins, making it a beautiful houseplant when it is not in bloom, it also sends up spikes of waxy, bright yellow flower-like bracts that are long-lasting. Zebra plants do have a reputation for being somewhat difficult to grow because they require high humidity and consistent moisture.
You may get your garden questions answered by calling the new Master Gardener Help Line at 218-824-1068 and leaving a message. A Master Gardener will return your call. Or, emailing me at firstname.lastname@example.org and I will answer you in the column if space allows.
University of Minnesota Extension Master Gardeners are trained and certified volunteers for the University of Minnesota Extension. Information given in this column is based on university research.