Gardening 101: Kalanchoes

Kalanchoe, Kalanchoe blossfeldiana: “Flaming Katy”

On a raw gray winter afternoon, I happened to walk by a small grocery shop in my Brooklyn neighborhood and was halted in my tracks by a group of succulents in radiant bloom, covered with tiny, star-shaped yellow, red, and orange flowers: kalanchoes. These floriferous beauties are just the thing to lighten up the will-spring-never-come doldrums.

Kalanchoes are sun plants, so I had never tried one before in my mostly gloomy brownstone, but the orange one I selected is really lifting the mood of the place and its cold weather-weary residents.

Read on for everything you need to know about these cheery blooming succulents.

But first, how did kalanchoes come to brighten my brownstone? It’s actually a long story. You may find it hard to believe, but there was a time when it was difficult to buy a bouquet of fresh flowers in New York City. They were mainly found in fancy florist shops and they were expensive—relegated to special-occasion splurges such as Valentine’s Day, Mother’s Day, and Easter. Sure we had supermarkets, but we picked up sundry food items at cramped little delis where you could get a sandwich, some canned goods, and dairy items, and maybe choose from three or four bananas or perhaps an onion or two. That state of affairs began to change in the 1970s when Koreans began revolutionizing the small grocery store.

The Koreans flung open the doors to the convenience grocery business. They rolled their bins of fresh-from-the-farm fruits and vegetables out onto the sidewalk and along with root vegetables and other mundane essentials, these shopkeepers offered inexpensive bunches of flowers—and not just a few tulips or some tired carnations. Suddenly, for the price of a few subway rides, one could take home a selection of roses, lilies, African daisies, and all sorts of other blooms tied up in colorful ribbons. Seemingly overnight, a luxury had become a reasonable indulgence.

Today some small grocers have gone even deeper into the flower business, expanding their inventories into pots of herbs and vegetables for the garden as well as houseplants, and even perennials. In my neighborhood the shop where I bought the kalanchoes is The Bad Wife, which in addition to lots of plants also sells organic produce and gourmet food items.

Kalanchoe is a genus of about 125 species of tropical, succulent flowering plants in the family Crassulaceae. They are relatives of the jade plant and can be grown outdoors in warm regions. However, here in the northeast, they are mainly used as houseplants, prized for their ability to bloom continuously and largely trouble-free for weeks. The kalanchoe most commonly seen for sale is Kalanchoe blossfeldiana, a native of Madagascar. Until the early 1980s, this plant was considered unremarkable and was relatively unknown but, about 40 years ago, European hybridizers transformed it into the bushy little flower factory so popular today. Like many succulents, it has foliage that is quite appealing: scalloped glossy dark green leaves that, with enough sunlight, will develop a fetching reddish outline.

Cheat Sheet

• To keep the flowers coming, pinch back the flower stems when the blooms are spent.
• Kalanchoes prefer to be alone in small pots so avoid planting them together with companion plants.
• These plants are tolerant of dry indoor winter conditions but should be watered generously when the soil seems dry to the touch.
• Avoid placing these plants where pets will have access to them. Kalanchoes can cause heart failure if ingested by cats, dogs, or other wildlife.

Keep It Alive

• These plants need plenty of bright light but be careful to avoid subjecting them to direct sunlight in summer, which can burn the leaves.
• Plant in well-draining soil and do not allow the plant to sit in water as the roots are prone to rot if not permitted to dry out between waterings.
• Kalanchoes are very sensitive to cold and will die if subjected to temperatures below 40 degrees so don’t put them on drafty windowsills.
• Clay pots instead of plastic are recommended since this plant has extremely sensitive roots and benefits from the increased aeration that clay provides.

Because its blooms are so spectacular and long-lasting, K. blossfeldiana is frequently treated as an annual and discarded after blooming. However, this plant can be coaxed back into flower if you are patient and provide the right conditions.

Like poinsettias, kalanchoes require weeks of short days and long nights or artificial periods of darkness. Natural day lengths from October to March will promote the formation of flower buds, but if your plant is in a room with artificial light at night you will need to fool it with 14 to 16 hours of total darkness by covering it with a box or placing it in a closet at night. In the morning, return the plant to a spot where it will get sunlight during the day. In approximately six weeks, you should start to notice that the flower buds have become large enough to be seen above the leaves. At that point, you can discontinue providing artificial nights and let the plant experience a natural day and night cycle, which should bring it into flower.

Who wouldn’t want to add a kalanchoe to a houseplant collection? For design and growing tips, see Kalanchoes: A Field Guide in our curated guides to Succulents & Cacti 101.

• Succulents: 8 Tips to Help Your Favorite Indoor Plants Survive Winter
• Succulents Explained: How to Identify and Grow 12 Favorites
• Everything You Need to Know About Succulents

N.B.: This post is an update; it was first published March 2018.