By Bev Johnson

Master Gardener

Petunia has always envied her Mother in Law’s ability to grow Christmas and Thanksgiving cactus. They are huge, the size of a bushel basket and she gets them to bloom at the proper time. Petunia finally got up the courage to ask Alma (she is quite a formidable woman) if she could have a slip of the Christmas cactus. Not only did she get a slip. She also got a lesson in how to grow it and how to tell them apart. This is what she was told.

The way to tell the 2 apart is to look at the segments, more properly called phylloclade’s. The Christmas cactus, as is fitting, has pointed lobes on the edges of the segments, like spruce needles. The thanksgiving cactus segments are rounded and smooth. Just to make things more confusing, there is also a cactus that blooms in the spring-the Easter cactus. Why then, since the first two are cousins, do they bloom at different times of the year, the Thanksgiving plant 6 weeks earlier than the Christmas one? It is all due to the length of the day, which is how much light the plant gets. The Thanksgiving cactus needs 12 hours of light during late summer and early fall to trigger flowering. The Christmas cactus has a shorter critical need for hours of light.

These cacti are native to Brazil and in their native environment grow on trees like orchids and other bromeliads. One would think then that they would require warm temperatures until you hear that they grow at 3,200 to 5,500 feet in the mountains. This is why they want house temperatures between 65 to 72 to bloom. That is why grandma was able to grow them so successfully. She had single pane windows and not much insulation. She probably did not stay up to watch Jimmy Kimble or Stephen Colbert either so the 8 hours of dark the plants required to bloom weren’t a problem. If you like to watch late night T.V. and want to ensure your new baby blooms, in mid -September, put the plant in a room or closet that has no light on during sunup and sunset. Bring them out in April and they should bloom at the proper time. Another tip, put them outside in the summer in the shade. Leave the plant out until the temperatures fall to 50 degrees. Bring it in and put it in an east or west window. Keep the temperature at about 57 degrees.

Now to propagation. Fill a 4-inch pot with damp soilless mix. Remove about 3 or 4 segments from the mother plant that are at least an inch long and poke them about ½ way their length into the medium and cover with a transparent plastic bag. When you see new growth, repot, and begin to fertilize as you would any house plant. Add a teaspoon of 20-10-20 houseplant fertilizer to a gallon of water for early spring and when you bring them in in the fall. Reduce the dose to ½ a teaspoon for every time watering during the winter.  

Do not over water this plant. if the segments are full and soft, they don’t need water. If they look a bit wrinkled, water. More house plants are killed by overwatering than any other cause.

Unfortunately, Petunia has 10 brown fingers. Her cactus bit the dust 2 months later.