Blooming orchid plants are increasingly available and reasonably priced. Many people who have not thought of growing orchids may be moved to buy one on impulse. Orchids are also popular as gifts these days.
Most of the tropical orchids we grow are epiphytes, which get their moisture and nutrients from the air and rain and usually grow on other plants. Epiphytes, such as our native Spanish moss, are not parasites and simply use the tree as a base to grow on. Although rainfall is plentiful in most habitats where tropical orchids grow up in trees, water does not linger, and plants must be able to survive until the next rain. For this reason, many orchids have tough, leathery leaves to reduce water loss and water storage organs called “pseudobulbs” to store water.
Orchids also grow in the ground, and these are called terrestrial orchids. They are not as common in cultivation as epiphytic orchids, but we do grow some terrestrial orchids such as the Chinese ground orchid (Bletilla striata), nun’s orchid (Phaius tankervilleae) and Spathoglottis orchids. These can be planted in pots with potting soil or in garden beds.
Most of the orchid species that are native to Louisiana (and temperate climates in general) are terrestrial. We do have one native epiphytic orchid in south Louisiana, the green fly orchid (Epidendrum magnoliae).
The adaptation of most cultivated orchids to life in the trees makes them relatively easy to keep alive. The problem is that gardeners often have trouble getting them to bloom again, and most orchids bloom once a year.
It is important to remember that there are many kinds of orchids and that they come from a wide variety of habitats. Some prefer full sun while others like shady conditions. So it’s important to know what kind of orchid you have in order to know how to take care of it. If you don’t provide your orchid with enough light, it will not bloom well.
You must also know what kind of orchid you have in order to determine how to water it and what temperatures it needs – or even if it will grow here. Orchids native to higher elevations where the temperatures are cool would do poorly in Louisiana’s steamy summers.
Because it is so important to know what kind of orchid you have in order to learn how to take care of it, always check to see if there is a name tag in the pot when purchasing an orchid. If there isn’t a name tag, check with the staff at the nursery or florist where it is for sale. If giving an orchid as a gift to someone who is not familiar with orchids, do an Internet search using the name on the tag, find the appropriate growing information, print out a copy and provide that with the gift.
Once you know what kind of orchids you have and the growing conditions they need, they are relatively easy to grow. They will thrive indoors in a brightly lit window facing east, south or west. A shady north-facing window may not provide enough light to encourage blooming.
You can summer your plants outside during warmer times of the year. After nighttime temperatures reliably stay above 60 degrees, move them to a spot outside that receives the appropriate light. No more than a couple of hours of morning sun or dappled light (too much direct sun will burn the foliage) is needed for shade-loving orchids such as phalaenopsis and paphiopedilum, while direct sun for most of the day is preferred by sun-loving orchids such as vandas. Spending time outside also provides a temperature drop between day and night of at least 10 degrees and good air circulation, which orchids prefer.
Orchids that are epiphytes require a special orchid mix, not potting soil, when grown in containers. Orchid mixes are generally based on chopped fir bark these days. Many orchids should be potted in a medium-grade bark or medium-fine bark mix (medium bark with perlite and chopped sphagnum moss added).
When watering, you must run water through the mix until it is properly moistened. This is best done indoors at the sink, allowing warm water to flow through the mix until it is thoroughly moistened. Outside, just use a hose. Orchids that do not have water storage organs, such as phalaenopsis, should be kept moist, letting them dry only slightly between waterings.
To keep your orchid growing vigorously, fertilize them regularly from spring to early fall using a soluble fertilizer such as 20-20-20 following label directions. This can be accomplished by dunking individual pots into a bucket of fertilizer solution, applying a fertilizer solution with a watering can or using a hose-end fertilizer applicator if you have a lot of plants to fertilize outside or in a greenhouse.