Let me introduce you to Penelope. She’s been part of my family for two years, since my daughter brought her home one day from college. I’m responsible for her care and well-being. She’s a cutie, green with skinny pink spikes (which I learned are called spines), nestled in pebbles in a small white clay pot emblazoned with her name. And yes, Penelope is a cactus.
I have many houseplants that are green and thriving, but this cactus plant is a mystery. I had a cactus plant when I was a kid and recall it was easy going and didn’t require much attention or daily watering, so I decided to just let Penelope be. She sits in my bay window along with my other plants that get daily sunlight. I water her every now and then, and she seems to be doing OK, but she’s the same size she was two years ago. I’ve been wondering if I should be doing something more, so I decided to find out what I can do to nurture Penelope’s growth and continued survival.
Sean McNamara, owner of the Redding Nursery in Redding, quickly put my mind at ease. “Cacti are good houseplants to have because they’re pretty hard to kill if you follow watering and light guidelines — they thrive on being ignored,” Sean explained. “They’re easy to take care of and can go long periods without water. They’ll shrivel if left too dry, and they need less water in the winter than in the summer.” He advised me to water Penelope once a week until soil slowly drips out of the drainage holes at the bottom of the pot. When I told him Penelope never seems to grow, he explained that some stay small yet some grow very large, depending on the variety.
My next step was identifying Penelope, so I emailed Sean a picture. He determined that she’s an Echinopsis chacoana, known for its long spines and white trumpet-shaped flowers. “The spines help shade the surface of the cacti which helps lower the temperature of the surface and limits amount of water lost to the atmosphere, and they protect cacti from animals and people,” Sean said. I learned cacti are susceptible to few diseases and pests, such as fungus gnats and mealybugs. “However, they can grow bacteria if too much water combines with a warm environment, so allow the soil to dry out completely between watering. To prevent root rot, grow them in light, sandy soil, because it drains quickly to prevent bacterial and fungal growth,” Sean said.
Jeannie Mortensen, garden specialist/designer at Stew Leonard’s in Norwalk, explained that a cactus is a succulent. “Succulents are plants that store water in their thick, fleshy leaves. Not all succulents are cacti but all cacti are succulents!” Jeannie said, adding that there are more than 1,500 species. “The most popular type are the Mammillarias, which is also called the pincushion cactus. They usually have flowers and grow in a ball shape,” Jeannie said, noting that cacti and traditional houseplants are not that different from one another: “Both serve as decorative items in your home and clean the air. Cacti don’t have traditional leaves, although some have flowers.”
Prickly pear, golden barrel, and grafted Cereus are the most popular cacti, explained Kris Barker, owner of The Gardener’s Center and Florist in Darien, noting that most have spines and all flower at some point. “Some have small, inconspicuous flowers, while others have large, brightly colored, showy flowers. Most flower in the spring,” he said. “Not all cactus are prickly — some are completely spineless, and they can live for many years and grow very slowly.”
Cactus spines are modified leaves that serve several purposes, according to Kris. “Spines protect the plants from being eaten by foraging animals, provide shade for the cactus, and collect dew at night which drips onto the root zone of the cactus,” he said. “Succulents can go many months or longer without water because the spines store water, but you should water them once a week or every other week in spring and summer, and generally every four to six weeks in fall and winter.”
Penelope gets plenty of sun sitting in my front bay window, and Jeannie said that’s excellent. “Cacti also require bright light and warm conditions. The spiny, fuzzy types do better in full sun,” she explained, adding that cacti prefer growing in equal parts coarse sand, peat moss and perlite. Since Penelope is in pebbles, Jeannie suggested removing some of the pebbles and filling in with cactus soil, and also said that fertilization with a low-nitrogen fertilizer, such as 5-10-10, is important: “Your first fertilization application should be in mid-spring when cacti are in their growth period. Six weeks later, apply the second, and six weeks from then, apply the third.”
Jeannie advised growing a cactus in an unglazed clay pot to allow moisture to evaporate. “A glazed pot doesn’t breathe, which could damage the roots of the cactus,” she explained. “Water only when the pot is dry, and only water the first inch of the pot.” Occasionally, cacti can be attacked by tiny white aphids that suck the sap from cacti, or by red spiders, tiny red mites that live on the underside of leaves and puncture the plant. “Both can cause rapid damage. Use an organic pesticide to prevent further damage,” Jeannie said. Kris advised using the proper potting mix and careful watering to prevent issues with rot and keeping mealybugs controlled with an organic insecticidal soap spray.
Consider getting a cactus plant for your home, particularly during the holidays. “They’re beautiful and decorative, plus cacti are easier than a regular houseplant because they require less care,” Jeanne says. Penelope is all that and so much more.