Thanksgiving Cactus

A Thanksgiving Cactus

Utah State University Extension provides informal education outreach to residents throughout the state. This question-and-answer column is designed to give you research-based information whether your gardening interest is producing fresh food, creating a landscape area or anything in between.

Question: I’m going to get some rosemary topiaries to decorate with this holiday season. Can I plant them in the yard this summer?

Answer: You can move the potted topiaries outside in the early spring and keep them there all summer. Gradually move them into full sun, water thoroughly but infrequently, keeping in mind that rosemary can’t tolerate overwatering. Fertilize once or twice in the spring. Once frosty weather returns, you should move them back indoors.

Rosemary topiaries are not suited to our winter-hardy zone 5 climate, so if you plant them in the ground, they probably won’t survive the following winter. There are a few varieties that can overwinter here with careful placement and adequate winter protection, but their natural growth habits make most of them unsuitable for use as topiaries. Check the label on your plant to see if they can overwinter in our zone.

Question: My mother-in-law gave me a Christmas cactus and said it’s easy to take care of. Is there something I should do for it besides water it once in a while?

Answer: Christmas, Easter and Thanksgiving cacti are popular, easy-to-grow indoor plants because of their showy, colorful flowers which can be spectacular this time of year and will bloom all winter.

Put your plant in a location with bright, indirect light and normal indoor temperatures. Avoid drafty locations near exterior doors and dry air from heat vents. You can keep your cactus there year-round or you can place it outdoors in a shady location during the summer and then bring it back indoors once fall temperatures start to dip below 50 degrees at night.

Although they are true cacti, a holiday cactus isn’t as drought tolerant as other cacti you might be familiar with. They require thorough but infrequent watering. When the pot feels light and the upper surface of the soil is dry, it’s time to water your cactus. Make sure you water deeply enough to see at least some water come from the drainage holes in the bottom of the pot. If your Christmas cactus has flower buds on it, keep an eye on the soil moisture because drought stress can cause the buds to drop.

A holiday cactus doesn’t need fertilizer year-round, but in the springtime after the flowers fade it’s time to begin one-half to one-quarter strength applications of a complete houseplant fertilizer until early fall.

By springtime, your cactus will have dropped its blossoms. If you want to see blossoms again next Christmas, you’ll need to provide the right conditions at the right time. Your cactus will need six weeks of long nights and short days to bloom. Cooler night temperatures are also important. You’ll need to provide 14 hours of darkness each night and bright indirect light during the day. The night-time temperature shouldn’t rise above 68 degrees, but warmer temperatures will be fine during the day. Some people find it easiest to keep their holiday cactus in a seldom-used room where the lights won’t be turned on during the evening. Once you begin to see flower buds on the branch tips you can move your cactus to a location where you can enjoy its beauty again.

Have a gardening question? Contact USU Extension at gardenhelpdesk@usu.edu.

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