Gardening with Gary

Gardening Advice from an Expert

Christmas Cacti

Q. When should I trim Christmas Cacti?

A. These plants do not need any trimming. If you cut off the growing points, you risk interfering with the next flowering.

If you are seeking to shape up the plant a bit, as when one branch sticks out farther than all the others, the best time to prune off this excess is right after flowering. Wait until all the flowers are complete. Check the plant carefully looking for tiny tip buds usually with red tones. These would be more flowers. When the plant is finished, you may trim off unruly branches. Any later, and you will be trimming off the new growth which starts popping out in the early spring.

You may take these extra branches and stick in the pot to fill in more, or you may propagate them in separate pots to enlarge your collection.

By the way, there are fairly new hybrids being released which feature very hot pink, yellow and even orange flowers. Check you local nursery or mail order catalogs.

Someone wrote about Christmas cactus, but it was deleted from my mailbox. I will summarize as: My Christmas cactus was beautiful when I got it, all full of blooms.. Now, there are no more flowers and it looks droopy. What am I doing wrong?

A. Remember that Christmas cacti are a holiday plant which bloom during the short days of the year. They are called 'long night' plants, same as the Poinsettia and Mums. After they finish blooming and the days lengthen, they will not flower again until anywhere from Thanksgiving to Easter. There are various genera and species, thus their blooming period varies.

Watering seems to be the source of most problems with the Christmas cactus. The plant is a tropical-type cactus but is not quite as drought tolerant as the name infers. However, it is a succulent plant and can store a reasonable quantity of water in the leaves. Water thoroughly when the top half of the soil in the pot feels dry to the touch. Discard the excess water, then do not water again until the top half becomes dry. The length of time between waterings varies with the air temperature, amount of light, rate of growth and relative humidity.

After the blossoms fade, the plant remains green and new foliage appears. With a little extra care, you can bring it back to full bloom the following year.

While the Christmas cactus can adapt to low light, more abundant blooms are produced on plants that have been exposed to high light intensity. Inside, keep your plants in a sunny location. Plants can be moved outdoors in summer, but keep them in a shady or semi-shady location. Too much direct sunlight can burn the leaves. When it is time to bring the plants back inside in the fall, slowly adjust the plants to life indoors by gradually increasing the number of hours they spend indoors each day.

Well-drained soil is a must for Christmas cactus. Use a commercially packaged potting mix for succulent plants or mix your own by combining two parts potting soil with one part clean salt-free sand or vermiculite, with a bit of perlite added.

Pruning your Christmas cactus after blooming will encourage the plant to branch out. Remove a few sections of each stem by pinching them off with your fingers or cutting with a clean sharp knife. These stems can be rooted in moist vermiculite to propagate new plants.

Christmas cactus will bloom if given long uninterrupted dark periods. Begin the dark treatments in about mid-October to have plants in full bloom by the holidays. Keep the temperature 55 Fahrenheit at night.

With assistance from: http://www.hort.purdue.edu/ext/christmas_cactus.html

Judy writes~ I have a small Christmas Cactus which has no blooms set and the Holiday is upon us! What did I do wrong? It is my first attempt.

A. Possibly nothing. The flowering houseplant, Christmas cactus (Schlumbergia bridgesii), has two cousins, the Thanksgiving cactus (S. truncata) and the Easter cactus (S. gaertneri). Easy to care for, holiday cacti differ only in their blooming cycle. They are natives of Brazil and were given names of the holidays near when they bloom. Through hybridizing, many flower colors are now available, as white, orange, pink, yellow, red and some bicolors. Flowers of the Christmas and Thanksgiving cacti are tube-like and may be hooded. The Easter cactus has star-like red flowers and sets buds about between January 1 and February 7. The Thanksgiving cactus will bloom about a month earlier than the Christmas cactus. All are best grown in bright, indirect sunlight. Once weather warms in late Spring, you may place on a shaded porch or patio, or set pot down into the soil in a shady area. Bring inside before the first frost. From April 1 through September 30, water when the soil begins to dry out. Apply a balanced houseplant fertilizer every 2-3 weeks. In the fall, allow the soil surface to dry between waterings. Once your cacti are finished flowering, stop fertilizing and let the top 1/2" of soil to dry out before watering. When new growth appears in the spring, resume regular watering and feeding. They like to be slightly potbound and are usually repotted every 3 years in a mixture of two parts potting soil and one part peat moss and one part sand.

Assistance from Garden Guides

Gail writes~
I have two Christmas Cacti that bloom two times a year but never at Christmas. Right now they will probably be in full bloom for Halloween and will again bloom just before Easter. How can I get them back on schedule to bloom at Christmas?

Myrna writes~
I have been planning to repot my Christmas cactus. I have a plant I've had about 2 1/2 years and another I bought last year. I had planned to repot them together in a bigger pot. Now tonight I noticed that the older plant is already starting to form the flower buds for this year's blooms. The newer plant isn't forming anything new, leaves or buds at this time. I am not a confident gardener so I don't want to mess up and lose the flowers for this year. Since the first plant is budding out, should I wait until after it blooms to do any transplanting? Should I be feeding them now?

A. For years these plants have been called collectively Christmas Cacti. But, in fact, there are at least three distinct genera which, though related, grow differently and especially bloom at different times of the year. The first ones referred to are called Thanksgiving Cacti, the middle bloomers are the Christmas Cacti and the last to bloom are called Easter Cacti. This explains why some plants refuse to bloom during the Holidays as one hoped. They cannot be reprogrammed to bloom when you want their flowers. They are light-sensitive, so do not allow evening lights shining on them, even briefly, or they will not bloom. Do not repot while setting buds, but wait until the last flowers have dried. Do not multi-plant them unless you are certain that both plants are the same genus and will bloom at the same time. It is best to keep each in its own pot. Use clean, fresh potting mix and feed after new leaves appear, all the way until flower buds set. Then stop fertilizing until the flowers have dropped and vegetative growth reappears. They like a short rest, with no food and little water, then they will start up again. Plants do well in the shade outside during the summer months, but do not subject them to the slightest frost.