ONE GROWER’S TIPS ON KEEPING YOUR MOUNTED ORCHIDS ALIVE DURING THE WINTER INDOORS
During the heating season, all Northern climate indoor orchid growers get anxious about their mounted orchids. Sure, they were fine in August when sunlight was plentiful, temperatures were hot (sometimes too hot!) and the humidity was 80% even with the air conditioning on. But it’s a radically different environment when the sun is low on the horizon, night temperatures near windows get downright chilly, and the radiators are spouting bone dry air all over. What’s a home orchid grower to do? There is no magic solution, short of turning your closet into a growing room or building a conservatory on your roof, but the following methods are all worth trying.
Before you even start thinking about humidity, think location, location, location -- your orchids may be in the wrong place! We get a lot less light through our windows in winter, both in terms of day length and intensity. Plants that usually can’t take direct summer sun, like phals, may be much happier getting a few hours of morning sun in winter. Depending on the placement and exposure of your windows, some of them may get more sun due to the changing angle of the sun, but it’s still not as strong as it was in July. You should always be thinking about optimizing the position of your orchids as the seasons and lighting conditions change. Many indoor growers, even those blessed with southern exposures, supplement natural light with artificial sources during the winter, to keep the day length and total light exposure up to par.
I’m going to skip over using humidity trays and room humidifiers, because many growers already use them, and talk about methods you may not have heard of before.
Some growers claim misting does nothing to raise humidity in the long term, and so it’s practically useless. That’s probably true in a greenhouse with high ambient humidity, however, a thorough soaking with a spray bottle will keep the roots moist for a few hours in the dry atmosphere of a winter home. If you’re home during the day, mist your mounts two or three times at intervals. I’m even going to go out on a limb and say, contrary to common wisdom, that it’s perfectly OK to mist mounts in the early evening when you come home from work, as long as they’re not too close to a cold window or other cold spot, and they’re fairly dry by the time you go to bed, when the thermostats are turned down, the home gets colder and grow lights get turned off.
Many home growers rinse or dunk their orchids in the kitchen sink or bucket at least once a week. In the winter, you may want to dunk more often, if your mounts need to stay moist. Don’t worry, it’s almost impossible to overwater a mounted orchid; just leave them in the water for at least 20 minutes to allow the roots to become fully saturated. Here’s another reason to soak, and not just rinse mounted orchids: if you use tap water, as many of us do, you risk mineral build-up on and around the roots, which are particularly harmful to sensitive types like angraechoids. Soaking, especially in distilled water or collected rainwater, can help dissolve mineral deposits. A capful of vinegar added to a gallon or more of water may help if you suspect hard mineral deposits.
Yes; it’s not talked about much, but it’s true: showering with orchids is widespread, especially in winter. First, you save time (at least in theory -- my wife still yells at me to quit puttering with the plants and help get the kids ready for school. I think she’s just jealous of my rhynchovanda). Second, you can leave them in the shower to drip dry, instead of leaking all over the floor – just don’t forget to take them out! Finally, it gives you a chance to inspect your orchids up close and personal, to make sure they’re healthy and aren’t harboring any hidden pests. And they won’t make rude remarks about how you look, either.
The ladies at J & L orchids suggest hanging your mounts on something more absorbent: a mesh bag or piece of nylon stocking filled with wet spaghnum moss, or even a moss pole from a florist’s shop. The extra moisture helps increase local humidity around the mount. (Note: don't try, as I did, to go cheap and use regular kitchen sponges. They dried out too quickly, and they looked rather strange hanging on the walls!)
No, I don’t mean potting them in standard mix. Instead, place the mount in an unglazed clay pot with a thick layer of spaghnum moss, gravel, or coconut chips on the bottom. Soak the entire pot, and the evaporation from both pot and mix will help keep your mounts happy. The only danger here is having wandering roots attach themselves to the pot, but if you’re taking them out regularly to water them, it shouldn’t happen. I recently saw at an orchid nursery a very healthy-looking mounted brassavola stuffed, wandering roots and all, into a net basket filled with sphagnum.
That's group, not grope. Keeping mounted orchids close together, or even hanging them on larger houseplants, can create a wetter micro-climate that will keep exposed roots happy. Two dangers to guard against: pests moving from plant to plant, and crowding plants so close together that you get mold or fungus due to stale air. Humidity without air movement is a big no-no, so turn a fan on to keep things moving.
This may seem like a drastic solution, but sometimes you need to be able to let go of an orchid that just won’t grow well for you. Some orchids that like being mounted but can deal with dry winter air include brassavolas, some cattleya species like aclandiae and walkeriana, encyclias, some epidendrums, laelias, and tolumnias (equitant oncidiums). Of course, they’re all high light orchids, but you can’t have everything. Don’t forget deciduous types like calanthes, catasetums, cychnoches, and thunias, that can be basically ignored all winter. No dry air worries!
Until somebody breeds the perfect indoor urban orchid – grows hot ‘n humid in summer, dry, cold and dim in winter, stays compact and flowers all the time – we’re stuck with doing what we can to keep our orchids happy. Remember that high humidity and constant air movement are good for you as well as your plants: turn on the fans, keep refilling the humidifier, and dream about Spring!