http://www.shopping2000.com/shopping2000/venamy/ (World Wide Web Directory, 06/1995)INTRODUCTION TO ORCHID CARE
Orchids differ from other houseplants because most of them are epiphytes, and some are semi-terrestrial. Few are real terrestrial plants. Epiphytes, in their natural habitat, will cling to trees to grow. They are not parasites, so they do not take anything from the host tree. They get their water from rain, fog, and humidity and their nourishment from decaying vegetation (leaves, etc.) and from matter falling with the rain. Semi-terrestrial orchids usually grow on the ground, on decaying leaves, and on other vegetation.
Being epiphyte or semi-terrestrial, roots of orchids are either totally exposed to the ambient air (epiphyte) or grow in a loose compost of decaying matter which also allows for a lot of air circulation. Epiphyte orchids may be exposed to a tropical shower every day, but because their roots are exposed to the air, they will dry out within an hour or so. Roots of semi-terrestrial orchids are humid because the decaying leaves and other matter that they grow on hold water, but they do not tolerate soggy, stale conditions. Consequently, when artificially grown in pots, orchids should be grown in potting media that allow plenty of air circulation and that hold water according to the needs of the type of orchid. Potting orchids in soil is, most of the time, a death sentence.
POTTING MEDIUM
Most orchids can be grown in fir bark. Those requiring more moisture around their roots, do better in sphagnum moss, in fine bark or in tree fern. The important factor is that the type and size of the medium you use match the type of plant, and the size and type of container. Of the three materials mentioned (there are plenty of others, from bottle corks, to charcoal, to gravel, to nut shells, etc.) sphagnum moss will hold the most water, tree fern will hold less water, and fir bark will hold less than tree fern.
SIZE (GRADES) OF POTTING MEDIUM
Size of the material affects how much water it holds or how long it will take to dry between waterings. Fir bark and tree fern come in different grades (sizes) which are usually referred to as small or fine, medium, and large or coarse. Coarse bark may be anywhere from 1" to 1 1/2" chunks, whereas fine bark is from 1/8" to 1/4". Using coarse bark in a small 3" pot will make it dry probably within a day or so. Conversely using fine bark in a 10" pot may take 10 days or more to dry out.
DURABILITY OF POTTING MEDIUM
Potting media will eventually decay. As they decay they either turn sour or hold too much water and therefore not enough air, and this will damage the root system of orchids. The decaying process depends on the type of material (sphagnum moss, fir bark, etc.) and is affected by the frequency of watering and how long the material stays wet. In general, plants potted in sphagnum moss should be repotted every year, and plants potted in tree fern or fir bark should be repotted every two years.
CONTAINERS
Potting containers affect how fast the potting medium will dry out. Plastic pots will take longer to dry out than clay pots, and orchid clay pots, which have slits on the side, will dry out faster than regular clay pots. Orchids can also be grown in slatted baskets, usually known as vanda baskets. These will dry out faster than clay orchid pots.
WATERING
Over watering is the number one cause of killing orchids, and this refers to the frequency of watering, not how much water they get when they are watered. How often to water depends on the type of orchid, the type of container, the type of potting mix, the size of the pot, and the season. Small pots dry out faster than large ones, and clay pots or slatted baskets dry out faster than plastic pots. In general, you should water plants potted in sphagnum moss only when the top of the moss dries out. Plants potted in bark or tree fern should be watered once a week. If you doubt whether the plant needs water or not, then wait one more day. When watering make sure you give your orchids a thorough one. Because orchid potting mixes allow for a lot of air space, the water will run fast through the drainage holes, but the medium will hold its capacity of water if you water thoroughly.
FERTILIZING
The potting mixes mentioned above do not contain any nutrients for your orchids. You should therefore add fertilizer to your water. You should use one fertilizer to encourage and sustain a good bloom and a different one to grow the plant when it is not in bloom. The fertilizer to use to encourage or sustain bloom is one than contains a higher proportion of phosphorous (higher middle number) than the other two minerals mentioned on the fertilizer container and is often called "bloom" or "flower cracker" or "blossom booster". Typical formulas are 10-15-10, 15-30-15, 10-30-20, 3-12-6, etc. When plants are not in bloom, the type of fertilizer to use depends on the potting material. Orchids potted in bark should be fertilized with a high nitrogen formula, usually referred to as "orchid special" and the typical formulas will be 30-10-10 or 10-5-5. Plants potted in mixes other than bark should be fertilized with a relatively balanced formula such as 20-20-20, 18-18-18, 7-9-5, etc.
HUMIDITY
Orchids appear to be more demanding of humidity, but all blooming houseplants have similar needs. All plants need 50 to 60% humidity, and that's pretty much what most orchids require. Orchids in bud are sensitive to low humidity and to drafts. Forced air or air conditioners blowing on or close to them will dry buds and desiccate plants very fast.
TEMPERATURE
Temperature needs vary among three groups of orchids: cool growing, intermediate and warm growing. The cool growing orchids need daytime temperatures from 60¡ F to 80¡ F and nighttime temperatures from 45¡ F to 65¡ F. Intermediate orchids need day time temperatures from 65¡ F to 85¡ F and nighttime temperatures from 50¡ F to 70¡ F. Warm growing orchids require daytime temperatures from 70¡ F to 90¡ F and nighttime temperatures from 55¡ F to 75¡ F. A daytime range of 70¡ F to 90¡ F means a minimum of 70¡ F in the coldest part of the year and a maximum of 90¡ F in the warmest part of the year. Orchids need the 10 to 15 degrees difference between day and night temperatures. You cannot grow them successfully with constant day and night temperatures. Although they can occasionally take higher and lower temperatures than their ideal range, they will slow down as temperatures go beyond their range, and they may stop growing altogether if temperatures are 5¡ F or more beyond their range. Because temperature ranges overlap, you can grow cool type orchids along with intermediate types, or intermediate types along with warm types.
LIGHT
In terms of light, orchids also fall into three categories: low, medium and high light. In term of exposures, these are usually associated with east, west and south exposures. We are talking about unobstructed windowsills. Tall buildings, trees and overhangs may considerably reduce the light available at a window. Low light means from 800 to 1,500 foot-candles, medium from 1,500 to 2,500 FC and high means from 2,500 to 4,000 FC.
SHIPPING
Orders delivered by UPS, 3 Day Select or Next Day.
