It's like clockwork in our house. Once the days shorten and get cooler our holiday cactus start blooming. Depending on the plant, we have cactus blooming until spring. That's because holiday cactus aren't just one type of plant. There are Thanksgiving cactus, Christmas cactus and Easter cactus, all blooming at different times. When shopping you can tell them apart. Besides the flowering times, the Thanksgiving cactus has jagged, pointy leaves or modified stems. Christmas cactus has more rounded leaves and Easter cactus has bristles emerging from their leaves.
Unlike desert cactus, these epiphytes grow in humid jungles and like water. But water only once the leaves start to wilt and shrivel and let them dry out between waterings. To stimulate flowering, in fall place your holiday cactus in a cool 50 to 60 degree, bright room for 1 to 2 months. A protected porch or spare bedroom is ideal. Also, place them where they won't get any artificial light at night. Flower initiation is stimulated by 12 hours of continuous darkness.
Watch for insects on your holiday cactus as well. Fungus gnats enjoy the organic material in your potting mix. A simple solution is to repot the cactus after flowering with fresh soil. Clean the pot with a 10% bleach solution. Aphids will attack new growth but can be remedied with sprays of insecticidal soap. Mealy bugs look like puffs of cotton but can cause damage to your plant. I dab individual mealy bugs with rubbing alcohol on a cotton swab to kill them.
