Houseplants: Good Apples, Bad Apples

There is nothing quite so frustrating as going to the store and finding an absolutely wonderful houseplant, bringing it home, caring for it and in just a few short weeks the tips of the leaves brown and the leaves change color or simply fall off.A few questions come to mind. Did you buy a plant that was totally inappropriate for the location? Did you buy a plant whose needs were more than you could satisfy? Or did something happen to the plant before you bought it that made it destined for compost? To some degree the answers to these questions don’t really matter. Your plant died, you’re frustrated and you utter the words, “I’m never buying another houseplant.” Yes, you will!

I can offer a little help. Just as there are automobiles that should have never have been made (does Edsel ring a bell?), cellphones whose batteries burst into flames and children’s toys that get recalled due to lead contamination, there are also plants that you should probably never buy—or at least if you buy them, do so being forewarned. Here’s my list of those destined for failure, so caveat emptor.

Let’s start with poinsettias, a scrawny and generally unattractive plant native to Mexico. Plant breeders have been able to turn this ugly duckling into Cinderella. But the magic spell is short-lived. In the process of growing the poinsettia cuttings, which become our holiday decorations, the plants are sprayed with chemicals to keep them short and tight. They are manipulated with artificial lighting and shading to ensure that they color up right on time, and they are pumped up with fertilizers to make them appear healthy and robust. When we buy them they look great, and as long as you have tempered expectations these plants are great to have around during the winter. But, if you think you’re going to get one to look the same next year while at the same time keeping it disease and insect-free, man have I got a great bridge deal for you.

Next on my worst list is the Norfolk Island pine. This is another plant that you see around at this time of the year, as it makes a nice living Christmas tree for a tabletop or small apartment, and it will continue to grow after the holidays. But it does grow, and in some conditions quite quickly. When you prune it to try and control its growth it loses its characteristic upright stature and becomes gnarled and quite unsightly. And no, it is not hardy and you can’t plant it outdoors.

Another plant that you begin to find in supermarkets and big boxes at this time of the year are gardenias fully budded or flowering. The combination of the lush, glossy green foliage with the delightfully scented flowers is hard to resist—and after all, it is a houseplant. The gardenia, however, has to be considered a “disposable” much like the poinsettia and your expectations need to be dampened.

Like the poinsettia, these plants are “timed” and treated to flower when the grower and retailer need flowering plants in the retail trade. And while they are not easy houseplants, unlike with the poinsettia, it is possible to re-bloom them. But again, remember that they are not hardy and they require special temperature regimes to initiate bud set, and they like it on the cooler side when flowering. On the minus side, they are virtual magnets for several insects, most notably the two spotted spider mite. To the experienced plant person, this mite is easy to spot and control, but for most of us by the time we see the mite damage it’s too late—and the infestation can endanger virtually every other plant in the house. Buy it, enjoy it, but consider it disposable.

There are two other plants to mention in passing, the false aralia (Dizygotheca elegantissima) and Japanese aralia (Fatsia japonica). These are two wonderful foliage plants that are easy to care for, and each has its notable and very different foliage. What they do share in common though is a definite dislike for cold. Keep them away from drafts and cold windows. I’ve seen both of these plants defoliate overnight when the ambient air temperature suddenly drops by 15 degrees or gets below 40 degrees.

Another group of plants that exhibits the same characteristic are the crotons (Codiaeum variegatum). With magnificently colored foliage in a variety of shapes and forms, the crotons are also extremely cold-sensitive and should not be purchased if they are displayed outdoors in December (or later) and should not be purchased on very cold days … even if it’s a short walk from the store to your car. When damaged it’s not uncommon for this plant’s foliage to take on the look of overcooked bacon.

Then there’s the plant of ultimate frustration or, for the optimist, challenge, the bird-of-paradise (Strelitzia reginae). If you’ve ever seen this plant in flower you know how striking and unusual it is. The foliage is green, long and strap-like, all emerging from the base of the plant at the soil level. A single plant can easily fill a 2-foot-wide pot and take up a space of 16 square feet. Because the plants need warm daytime temperatures and cool nights, few have the patience to wait the five to seven years it takes a small one to get to flowering size. The plant enjoys being pot-bound, and I think that’s the only way it will flower. You can buy a large plant and wait only a year or two, but you’re talking big bucks for such a plant. From a 4-inch pot to a flowering giant takes years, but in the interim you’ve got great foliage. And when it does flower … WOW.

There are other flowering plants that you can buy in flower and a few that have striking foliage that becomes their calling card. Many of them have one thing in common though—they are annuals, tropical annuals, and once they flower … they’re done. The pink polka dot plant (Hypoestes phyllostachya) is a great example. Available in various renditions, it has splashy spotted foliage that makes a great low-growing dish or table plant and can be used as a bottom cover plant in indoor pot arrangements. It certainly brightens things up, but it needs higher humidity to survive and is an annual and once it begins to flower, its decline is imminent. It can be trimmed to remove developing flower stalks—and this will prolong its usefulness—but unless you are willing to take cuttings and start new plants, don’t plan on keeping the original for more than a year.

Another plant that will grab your attention is the zebra plant (Aphelandra squarrosa). Usually sold in 4- to 6-inch pots, this plant has not only striking foliage that’s striped like a zebra, but also brilliant spiked yellow flowers. This is another one that has to be considered short-lived and very sensitive to temperature changes. Sudden exposure to cold or rapid drops in temperature of 15 degrees or more cause the foliage to drop, and the plant will quickly die. It is also very sensitive to overwatering. When the flowers fade they must be quickly removed and new ones may (or may not) appear weeks later.

Well, just some shopping advice. Fill the house up with color and bring the garden indoors by all means. Just do it with an open eye and educated expectations, and you and your plants will find a balance. Keep growing.