Orchids 101

Orchids are not like traditional potted plants. They are epiphytes which means that they do not grow in dirt, but instead, by hanging onto the bark of trees. There are some orchids, most notably lady slippers, that are terrestrial and grow in the fertile soil of the jungle floor.

With proper care, an orchid can be in bloom for months each year and live indefinitely.

Temperature & Environment

Not giving orchids enough light is the most common reason for them failing to bloom. So, how much light is enough? The answer is “as much as they will take without burning.” This means that the foliage should not be a lush, dark green. South and east-facing windows generally work best for orchids while west windows can be too hot in the afternoon and north-facing ones are usually too dark. The recommended storage temperature varies based on the variety of orchid you have. For ideal flowering and growth though its important for them experience 15°F change in temperature from day to night with that range generally not dipping below 55°F or exceeding 90°F.

Orchid’s roots, and eventually the entire plant, will die if they do not get enough air and this is the reason that, with the exception of a few terrestrial varieties, orchids do not grow in soil. Orchid potting media should be open, with exceptionally good drainage, yet capable of holding sufficient moisture to support the plant’s needs. Check out this orchid potting mix page for more information on pre-made mixes. Orchid plants are also intolerant of a stale, stagnant environment. You should strive for a light atmosphere and gentle air movement at all times. For orchids grown in the home, this can be provided by an overhead paddle fan set on its lowest setting or a portable oscillating fan directed away from the plants.

Indoor orchid plants also require sufficient humidity. For best results, this should be around fifty to seventy percent. There are a number of ways to increase the humidity in your home, one of which includes placing a water-filled saucer or tray of pebbles beneath the orchid plant. You can also mist the plants daily, or use a humidifier.

Growing Medium

To help your orchid thrive, use moist, well-drained soil and a type of growing media, such as charcoal, fir bark, redwood, corks, peat moss, sand, potting soil, or rocks. A basic mix for growing orchids generally consists of fir bark, coarse perlite, and sphagnum moss. When using bark, think about the type of orchid you are planting. In most cases, the grade of the bark is dependent on the orchid species. For example, phalaenopsis orchids prefer coarse bark, while cattleyas enjoy medium bark and young orchid plants thrive in a finer bark.

Water & Feeding

When orchids are watered, they should be watered copiously. Orchids require ample water but should be allowed to dry out before watering again. Water should be provided until it runs freely from the drainage holes. Not only does this soak the potting medium, but it also flushes out salts that naturally accumulate. At a minimum, try to thoroughly water your plants at least once a month. Avoid over watering though as this can lead to root rot.

Orchids will grow and flower, given that their other requirements are met, for fairly long periods without fertilizer, but you’ll get better results with some level of feeding. Typically, plants are fertilized once a week during the summer and every two weeks in the fall and winter. It’s wise to do this weekly or bi-weekly, especially when they are producing new growth. You can decrease this to monthly or bi-monthly once they are established. When the plants are dormant, discontinue fertilizing your orchid altogether. Regardless of the fertilizer that you chose to use, most experienced growers use no more than ½ the label-recommended strength. It’s best to water first to wet the potting medium before you fertilize. Fertilizers used on orchids should contain little or no urea.

You can visit this page to find a fertilizer designed for orchids.

Common Orchid Problems

Orchids, like a number of plant species, are affected by pests and diseases, including small sap-sucking diapsid scale insects. Properly identifying the source of the problem is the key to understanding how to treat your orchids and remove the disease. These critters cover the leaves and stems of glasshouse orchids. They come in the shape of flat rounded whitish brown insects that measure around 2mm in length. Other types of diapsid look narrow in appearance and are covered with a fluffy white wax. They are often found at the base of the leaves in a cluster.

Types of Diseases

Orchid diseases can be fungal, bacterial or viral. The common fungal diseases you see on your orchids are sooty mold, petal blight, rust and black rot. They are usually caused by high humidity without sufficient air movement. Insects and pests also spread the fungus. The honeydew produced by aphids also promotes fungus growth.

Bacterial diseases like brown rot are usually caused by being too cold and/or too humid. The bacteria can also be carried by insects or pests crawling from an infected plant to another plant. The bacteria easily contaminate healthy plant tissues, pots, potting material, clothes and other supplies.

If your orchid plant has a virus, you should immediately throw it out. (Burn it, quick!) Viruses are spread by pests or infected tissues of another plant. Even though they are usually not fatal immediately, they are pretty much incurable. Your poor plant will just get weaker and weaker over time, and the flowers might be deformed. Not pulling the plug on your diseased plant could mean spreading the virus to your entire collection.