February 25, 2010

Orchids Plants

Orchid Plant Care

By William M Robinson

It is important to provide the proper light conditions to grow your plants to their optimal potential. Orchids can be grown on bright windowsills or under artificial lights. Of course, if you are fortunate enough to have a greenhouse or a sunroom, plants can be grown with even greater results.

The best exposures for growing orchids are east, south and west. They should be grown in full sun light a sheer curtain or window screen is important to diffuse the sun's rays. Note how many hours of sun each window receives as trees and overhangs will cut down on the amount of sun.

Orchids that have dark green foliage, but do not flower, are usually not getting enough sun. Leaves should actually be a yellow-green color, not dark green. Each new growth produced should be as large as or larger than the previous one. Strong pseudobulbs will produce beautiful flowers and will ensure you that your plants are receiving the proper light.

Orchids thrive outside in the summer. In our area this is from mid May until October. Please be careful when moving your plants outdoors as they will need some protection from the full sun. A shade cloth area or the filtered light provided by a birch or willow tree will prevent them from getting burned by the summer sun. If your orchid has not been receiving the proper amount of sun light, you will need to increase their exposure gradually over the course of a few weeks to prevent burning. Remember, just because a plant gets sunburn, it does not always mean it is the wrong exposure for the orchid, only that it was given too much sun too quickly.
This guide shows what plants will grow well in which exposure; however, plants that require less sun light can be grown in the same window when shaded by more light loving plants.

East Window: Phalaenopsis, Oncidium, Paphiopedilum and Phragmipedium

South Window: Cattleyas, Vandas, Oncidium, Dendrobium and Cymbidiums

West Window: Phalaenopsis, Oncidium, Dendrobium and high light Paphiopedilum

North Window: Jewel Orchids and other low light species

Orchids For Under Lights: Phalaenopsis, Oncidium, Paphiopedilum, Masdevallia, Pleurothallids, Compact and Miniature Cattleyas

Artificial Lighting
If you do not have a window that provides sufficient natural sunlight, consider supplementing with grow lights or completely going to artificial lighting. One advantage of growing under lights is that you are able to grow in any room in your house. Complete light carts are available and come equipped with lighting and humidity trays.

To receive the proper intensity, orchids will need to be within 3-6 inches of regular florescent lights. When using high intensity lights carefully follow the manufacturer's instructions regarding the proper distance from your plants to prevent burning the foliage. Most lights will also produce a certain amount of heat so be sure to have good ventilation and air movement.

In order for your orchid plants to flower consistently, you will need to adjust your light timers to replicate natural daylight. We suggest increasing one hour each month from January (11 hrs) until June (16 hrs) then decreasing one hour starting in July (15 hrs) until December (10 hrs).

The basement is an excellent choice for a growing area because it will stay at a uniform temperature and will have sufficient humidity. Heavy duty plastic or reflective aluminum can be used to insulate ceiling joists and curtain off an area. By hanging florescent light fixtures over plant tables and adding an oscillating fan for air movement, you will have your very own subterranean greenhouse.

Orchids For Under Lights: Phalaenopsis, Oncidium, Paphiopedilum, Masdevallia, Pleurothallids, Compact and Miniature Cattleyas

The general rule is to water once a week. However, orchids need to dry out slightly between waterings and then be soaked thoroughly. The old slogan says, "When in doubt do without."

Should you experience shriveled and leathery leaves or pseudobulbs, a close inspection of the roots will be necessary to decipher the problem. Over watering will cause the roots to rot, while symptoms of under watering will be dehydrated roots.

We recommend feeling the weight of the pot before watering, then again after it has been watered thoroughly. This will give you a better idea of whether it needs water or not. We do not suggest the finger test because you can only feel the top inch of the media which will not let you know the rest of the pot's moisture content.
Keep in mind clay pots will dry faster than plastic pots and orchids grown in sphagnum moss will tend to take longer to dry. When grown mounted or in slatted baskets without potting media, plants need to be watered nearly every day. Orchids can be grown in almost anything as long as you adapt your watering accordingly.

Temperature and Humidity
Normal home temperatures are fine for growing most orchids. Temperatures of 70-80 degrees in the daytime and 60-70 degrees at night are ideal. Always keep plants away from hot or cold drafts.

Many orchids, like phalaenopsis, need a drop in temperature for several weeks during the fall to set their flower spikes. This is accomplished by moving them outdoors or opening the window in which they are growing when the outside night temperature is in the mid to upper 50's. Cymbidiums like to grow outside during the summer with plenty of light and fertilizer. They require a 20-30 degree drop in temperature in the late fall to set their flower spikes. So leave them outside until danger of frost.

If you have trouble growing cool or intermediate orchids, consider growing them in your basement under lights. Beware of cooling your orchids using an air conditioner as they remove humidity from the air and may cause the flowers to wilt. A good level of humidity in winter can be attained by running a humidifier or by putting humidity trays under your plants. Feel free to spray your orchids with a mister on any sunny day to increase the humidity level.

It is always very important to feed your plants, not only while they are growing, but also when they are in bloom. Like all living things, when fed properly, they will grow stronger and produce more flowers.

Our product of choice is Dyna-Gro, but any balanced fertilizer may be used. Brands such as Miracle-Gro and Peters are also known for quality fertilizers and supplements.

We recommend watering the plant prior to applying fertilizer and then following one of the two sets of instructions on the manufacturer's label. One is for feeding (1/4-1/2 tsp/gallon) weekly and one is for intermittent feeding (1-3 tsp/gallon) every 2 to 4 weeks.

If you cannot fertilize as often as you should, then use a timed release fertilizer to supplement regular feedings. Depending on the brand and formula, granules will last from 3-12 months. Top dress your plant with the manufacturer's recommended amount. Sprinkle the feed evenly across the surface of the mix taking care not to get it close to the new growths. Do not use this type of fertilizer with sphagnum moss. Because the moss is constantly moist, it will continuously release nutrients and could burn the roots of your plants.

Repotting is the part of orchid growing that hobbyists consider most intimidating. However, with some guidance, even the novice grower will find it to be an easy and rewarding experience. First decide whether you simply want to shift your plant or divide it into several pieces. To shift your orchid, remove the plant from the pot and clean the old mix off the roots. Then choose the proper pot size allowing room for two years of growth. When dividing cattleyas and other orchids with similar growing habits, we recommend leaving 3-5 bulbs per division. Decide what size cutting you want to make. Then use a sterile knife to cut down through the rhizome and the roots staying as close as possible to the older growth. Choose the proper pot size allowing for two years of growth. Next consider what type of container will suit your orchid and watering schedule. Most orchids grow well in plastic pots. However, if you have a tendency to over-water, clay pots may work better for you since they are porous and will dry out faster. Clay pots, because of their extra weight, will also help top-heavy plants to remain upright.

We recommend potting in a fir bark mix. This media was originally developed by our founder George Off in the1960's. Fir bark is still used extensively by many commercial growers in various modified formulations.

Orchids like good drainage, so we suggest using large bark or sytrofoam peanuts in the bottom of the pot. Place the plant with the newest growth farthest from the edge of the pot and fill in with mix. Make sure to get the right level for the potting medium. Be careful not to bury the eyes at the bottom of the bulbs and leave some room for water in the top of the pot.

Note: There is some controversy as to how hard the mix should be packed. We have always tamped the mix in tightly, while others just use their fingers. The main point is to pot firmly, eliminating most of the air pockets.

If you are potting in sphagnum moss, just remove the old medium and choose the proper pot size depending on the amount of roots. Spread the roots over a cone of moss, then wrap some more moss around the root ball and place it into the new pot. Phalaenopsis should be centered in the pot, while orchids that grow like a cattleya need to be placed with the new growth farthest from the edge of the container. Be sure to cover all the roots. Moss should be spongy and should not be packed too tightly.

Staking and Grooming
Good staking and grooming habits are one of the easiest ways to make your collection look its best. By removing a few yellow leaves and trimming scarred or damaged portions, all of orchids will look better. A new single edged razor or sterile scissors will work well for cleaning up your plants.

Orchids will take up less room if they are staked upright. New growths should be staked to allow light into the rhizome area of the plant and will also ensure that the flowers will have good placement when they open.

Pests and Diseases
Bugs create a host of problems and can seriously damage a collection if left untreated. Scales, mealybugs, aphids and mites are the most common orchid pests. You will find that bugs are attracted to certain genera. For instance, mealybugs like phalaenopsis and bifoliate cattleyas, while scale prefers cattleyas and cymbidiums. Aphids are attracted to the buds and flowers of dendrobiums and oncidiums, but they do not discriminate between orchid genera. Spider mites will show up when there is a lack of humidity especially on dendrobiums, oncidiums and cymbidiums.

Always keep a close eye out for bug damage. They like to hide under leaves and sheathing and, if left untreated, they will quickly spread through your collection. By removing old sheathing once it becomes loose, it will be easier to recognize the early signs of an insect problem. Scale depletes chlorophyll leaving yellow spots on the foliage. They also love to feast on the tender eyes at the base of the pseudobulbs. Aphids will leave a sticky residue on the foliage below where they are eating. Spider mites can be identified by the silvery scarring they leave under the leaves. The good news is that most orchid pests are easily exterminated. Home and garden sprays will provide a long list of bugs they will kill. We recommend spraying the plant, then manually cleaning it as much as you can with a Q-tip or toothbrush, followed by another treatment of spray. Follow up treatments after five to seven days may be necessary to fully eliminate the problem.

Schultz, Bayer and Ortho all carry a good line of sprays that are available at any garden center, hardware store or home improvement warehouse. For a less toxic approach, we recommend using denatured alcohol, neem oil or insecticidal soap. Remember to always be extra careful of what you spray, especially on the flowers, and always follow the manufacturer's instructions to prevent plant and flower damage. Slugs and snails chew flowers and buds as well as the tender new roots and growths. Bait is readily available and will do a good job of ridding your collection of these pests. Ants can be a problem, especially when moving your orchids back inside in the fall. Orange Guard, a citric acid product, is a good way to eliminate these pests. However, if they are down in the mix, you will need to drench the pot with an insecticide or repot the plant.

Other orchid problems, like rot and fungus, can be treated by first removing the infected area with a sterile tool, then applying a fungicide spray or powdered cinnamon, which is a good natural fungicide. Improved air circulation can help prevent a reoccurrence of this problem. Flowers that have botrytis (small dark spots) should be removed to prevent spores from spreading to others blooms.
Any orchid exhibiting signs of a viral infection should be totally segregated as contact with diseased plant fluids will cause the virus to spread and may contaminate other plants. Any questionable plant should be tested and if it tests positive, it should be destroyed as there is no cure for orchid viruses. This is why it is so important to use sterile tools and equipment when handling your plants. Human contact and chewing insects are also vectors for spreading viruses.
We hope these tips will help you to be successful with your orchids. There are many orchid books, magazines, periodicals and internet sites that can help you to become a better grower. We also recommend that you go to the American Orchid Society for individual culture sheets for all types of orchid genera. You will find growing orchids to be an exciting hobby. However, a word of caution, orchids are extremely addicting! Once you purchase your first plant, you will be 'hooked' for the rest of your life!

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