Sometimes providing extra light in the winter is not the problem for would-be plant growers. Temperature is the limiting factor. For one reason or another folks often have very cool spots in their abodes in which they want to grow plants. What to do?
One of the very best plants for cool locations are Tillandsia, so called "air plants" because they take in all their nutrient through their leaves and not roots. This makes them "epiphytes," which means they don't need to be grown in soil; they can take in all the water and nutrients they need through their leaves. Their root system is used to anchor the plants to other plants or bark.
Actually, Tillandsias are members of the Bromeliad family, the very ones mentioned last week as not needing supplemental lights. They are extremely easy to grow and the ones for sale commercially usually produce blooms if given the proper conditions.
Best of all, Tillandsia plants can withstand an extremely wide range of temperatures from 35 degrees to over 100. There is even one species that can withstand some pretty good frosts. What this means is you can mail order in the winter if you can't find some through local sources.
Tillandsia produce flowers once in their lifetimes but reproduce often by producing diminutive new plants called "pups." Some plants can produce as many as 6 to 8 every year. These form into some pretty nice looking clumps that bear flowers every year. Bromeliad flowers are colorful, bizarre and interesting. They also usually last a couple of weeks.
Care for Tillandsia is simple. The big thing is that, while they are called air plants, they do need watering. Do it right and they will thrive. To do this properly enough water has to be applied each watering so that it runs off the leaves. These have special trichomes that suck up and hold water.
If you simply mist these plants, they probably won't get enough water. Take them to a sink and pour water on them, if possible. You can overwater and rot a plant, especially the ones that form thick "bulbs" at their bases. These should never be allowed to sit in water. This and making sure leaves dry on their surface (and in the well they form) within a few hours will keep yours going strong.
How often does one water? Well, it depends on the plant. Feel the leaves of the plant immediately after you water it. They will be stiff. After a week, try again. They will be much limper. While they can go for a long time without water, it is best not to let the leaves go completely limp and get too soft. Once a week would be a minimum, with two and perhaps even three times a week if grown where it is hot.
Remember, these plants take in nutrients through their leaves, not roots. If you use distilled or RO (reverse osmosis) water, they won't get what they need. In fact, osmosis causes the nutrients in the leaves to move out of them when pure water is used. This will kill the plant. Some growers swear by rain water and melted snow and contend these contain the proper amounts of nutrients to keep Tillandsia thriving. Others use a 1/4 to 1/2 dilute houseplant fertilizer every time they water.
While cool can be the rule for these plants, they do need some light, though not necessarily supplemental light. A couple of hours of sun from a well-lit window will do just fine. They can be taken outdoors in the spring and left there all summer.
Tillandsia are often grown on other plants. They are not parasitic, so don't worry about hurting the host. Some folks attach these plants to curtains or arrange them in bowls. There are all sorts of ways to display them.
If you can't find Tillandsia locally, check the web for sources. Start at www.airplantsupplyco.com/collections/air-plants-all.
Jeff Lowenfels is America's longest running gardening columnist. You can reach him at www.teamingwithmicrobes.com
Jeff's garden tips
• Watering: Letting water sit for a few hours degasses the chlorine in it and brings it up to room temperature, both of which are appreciated by plants.
• Poinsettias: Look for them this week. They hate drafts and should be covered when taking home.