Grow Christmas cactus under lights in winter

Christmas cactus can thrive in winter if given proper lighting: one warm white and one cool white fluorescent tube lighting the plant for 14-16 hours each day. (Walter Reeves for The Atlanta Journal-Constitution)

Credit: Walter Reeves

Credit: Walter Reeves

Christmas cactus can thrive in winter if given proper lighting: one warm white and one cool white fluorescent tube lighting the plant for 14-16 hours each day. (Walter Reeves for The Atlanta Journal-Constitution)

Q: I inherited three Christmas cacti a few years ago. They thrive during the summer when they’re outside in my screened porch, but inside during the winter, they shrivel up. A grow light helped somewhat. What is the proper type of light and how long do I leave it on? J.P. Schoemer, email

A: A fluorescent fixture with one warm white tube and one cool white tube works well for overwintering plants. Hang the tubes 12-15 inches from the top of the plants. Use a timer to give your Christmas cacti 14-16 hours of light each day. They can also be grown in west-, north- and east-facing windows, but south-facing windows are too bright. Your Christmas cacti should receive enough moisture that the potting soil does not dry out but does not remain wet for long.

Q: Where does English ivy come from? Something tells me it’s not a native of England. Jonny Hibbert, email

A: You are incorrect, good sir. Two species of ivy are native to Britain: Hedera helix, which we call English ivy, and Hedera hibernica, called Irish ivy. The latter is said not to climb; instead, it sprawls on the ground. Some say that the invasive ivy we call English ivy is in fact Irish ivy. There are ways to tell the difference if you have a microscope. The two have a different number of chromosomes, which prevents interbreeding. Bottom line, it doesn’t matter what you call it; ivy can easily grow out of control and require removal.

Q: I recently chopped down my canna lilies. I have had four days of breaking out in severe rashes all over my body. My doctor prescribed antihistamine and cortisone cream. Canna flowers are pretty, but after this huge reaction, they have to go. Diane Bramley, email

A: You are not alone. I have collected several accounts of people having a bad skin reaction after handling canna leaves and seed pods. It’s not very common and I’m not a dermatologist, so I have no idea what causes the ugly skin welts and rashes. An even more rare skin reaction occurs from handling evergreen passionvine, Passiflora caerulea. The victim in that case of severe dermatitis had festering red splotches on her skin. They did not itch like poison ivy but rather burned and stung at the slightest touch. Your solution to the problem is best: Don’t touch the plant anymore, and remove it from your landscape.

Email Walter at georgiagardener@yahoo.com. Listen to his occasional garden comments on “Green and Growing with Ashley Frasca” Saturday mornings on 95.5 WSB. Visit his website, www.walterreeves.com, or join his Facebook page at bit.ly/georgiagardener for his latest tips.