Oak Hill Gardens

Orchid Growing Information

You too can enjoy the most exciting growing hobby and can grow and flower many orchid varieties in your own home. They are amazingly sturdy plants, and many are suitable for home growing. There are many book titles (i.e. Home Orchid Growing, You Can Grow Orchids, Orchid Culture Under Lights, etc.) which explain how specific varieties can be grown and bloomed indoors. While the number of species orchids in existence in nature is over 25,000, only a few of the genera are ideal for indoor growing without a greenhouse or special growing room. In a hobby greenhouse, sunny or special growing room, possibly with grow lights in the basement, the amount of growing pleasure and satisfaction one can derive is almost unlimited.

Following some individual care requirements will insure success.
Temperature, humidity, light and air are part of this climate.

TEMPERATURES ideal for orchids depend on their origin and type. Warm growing orchids, such as Phalaenopsis, like 64-68 degrees F at night, about 75 degrees in daytime, while with bright sun it may be 80 and above. Intermediate growing orchids prefer 58-62 degrees F at night, 66-70 degrees in daytime and 75 plus on warm and sunny days. Cattleya, many Paphiopedilum varieties, and many species belong to this group. The cool growing orchids, such as Cymbidiums, prefer a night temperature of 45-55, 60-65 in daytime and 70 plus with the sun.

These general guidelines and temperatures may fluctuate depending on outside climate influence. Damage to plants only occurs when temperatures are allowed to go far above or below the suggested levels, or when plants are wet and cold. Many orchid varieties, bromeliads, and tropical plants can be grown successfully in the intermediate temperature range, while they might originate in differing climate regions in nature.

HUMIDITY for orchids is essential. Providing it as much as possible helps create lush growth. This may be done by the use of humidifiers, misting plants in the morning on warm and sunny days, and keeping ground floor and walks moist. Trays with gravel and water create a growing climate around the plants in home conditions. Providing protection from bright sun, lower night temperatures avoiding drafts or rapid air exchange will help retain higher humidity and create a better growing climate. During winter months many orchid plants are dormant, and will tolerate lower humidity better than in spring and summer while they are in active growth.

LIGHT is a very decisive factor in growing and blooming the orchid plant. Generally most orchids need protection from bright sunlight in Illinois from March to October. The plant structure will indicate the need for more shade or less, by foliage being hard and cactus-like on some orchids and tender, large and soft on others. Sunburn usually occurs when plants have been accustomed to short winter days and cloudy weeks. In February or March,. sunny days will bring extremely bright light and heat from the sun at the same time. More shade needs to be provided during spring and early summer months when new growths appear and will develop into bloom producing leaves. Greenhouses or homes which are kept cool during extremely hot weather, may be shaded less than those without cooling systems. More sturdy plants with more blooms will be the result.

AIR is generally available in sufficient quantity and good quality in most growing areas. Its circulation around the plants may be increased by the use of fans in a crowded greenhouse or growing room to dry off foliage after watering, or on dark and rainy days. Also when very high humidity causes a stuffy, stagnant climate, air circulation by fans or air exchange through opening vents will improve the condition. A very high humidity of 90-100% and stuffy conditions will not harm plants, but will create lush growth.

However, when the temperature drops to 62 degrees F or lower simultaneously, fungus spotting on blooms and plants may occur. Air circulation or slight heating will prevent this adverse growing condition. Evaporative cooling of greenhouses during summer months permits maximum use of light, fertilizers and air with resulting larger plants and more blooms. Bringing the factors of temperature, humidity light and air into a suitable balance for his plants is each grower's challenge, and makes outstanding growing and blooming possible.

WATERING, FEEDING, RE-POTTING and INSECT CONTROL are additional important factors to be handled by the grower to insure maximum growing success. Plants should be watered thoroughly when potting medium is completely dry. The frequency may be at 4-7 day intervals depending on pot size, growing medium, light, and humidity. Do not permit plants to remain wet at their root system more than a few days. Roots cannot breathe if completely wet, and will rot if plants stand in water. Clay pots permit a more rapid drying out of the root system after each watering, however, plastic pots are ideal for most young plants, Phalaenopsis, Paphiopedilum and Cymbidiums. These as well as many additional orchid genera do not like to dry out severely at their root system. RAINWATER is best for all your plants since it does not contain harmful minerals. It is especially important for tropical plants of all types. Lake origin water and humidifier water etc. is also better than most well water. Plants should generally be kept more to the moist side during their spring and summer growing season to insure large lush growths.

FEEDING your orchid plants will result in larger plant size, as well as larger and more colorful blooms. It should be done about every two weeks or as plants show need. We use 30-10-10, 10-5-5, 8-8-8, 10-30-20, 10-50-10 and 20-20-20 for most of our feeding according to directions given. Various fertilizer brands may be used with possibly equal results, however, the high nitrogen formula should be used for orchids in fir-bark mixes during summer months. Fish emulsion foods or other organic foods are also excellent for orchids and may be used alternately with an inorganic food during the spring and summer growing season. Dark green foliage indicates food presence in the plant in sufficient quantity, while yellow looking plants should be fertilized more often. Small doses of slow release foods, i.e. "Throw and Grow" 20-4-10 can be used for strong growing plants, or to "green-up" yellow looking foliage.

RE-POTTING of your orchid plant should be done when (a) the potting medium is soft and decayed, (b) rhizomes and plant growths overgrow pot edge and (c) when plants grow too large for the pot size. It is best done when new growths are growing up or in spring and summer. Only special orchid potting medium, like fir-bark mixes, or for some varieties, peat-moss mixes, should be used.

Our special "Oak Hill Orchid Mix," is most economical and superior to fir-bark, tree fern or osmunda fiber for use in the Midwest area. Miltonias, Odontiodas, etc. prefer to be re- potted in fall, while the winter months are ideal to re-pot Paphiopedilum after their blooming. Seedlings from flasks are best planted to community flats or pots from May to August into a fine grade fir-bark, peat moss, Perlite, and Vermiculite mix. Most orchids may remain in their pots 2 years, while many species, Paphiopedilum, Phalaenopsis, and Miltonias prefer to be re-potted annually. We are now using a modified "Fafard B-3" Pro-Mix for Zygopetalum and Phajus with excellent results. Plants in bark mixes should be re-potted very tightly. Plants potted to peat moss or "Pro-Mixes" should be potted very loosely. Fertilizers, wetting agents, and pH adjustments are contained in the Pro-Mixes.

INSECT CONTROL is only recommended and required when an infestation occurs. Common insects which attack orchid plants as well as many house plants are: scale, mealy bug, spider mites, aphids, slugs and snails. The suitable insecticides to control the listed pests may be obtained from us or your local garden center. Most insecticides recommended for roses may be used on orchids without damage to plants. Fungus diseases are less frequent in this area, and available fungicides may be used according to directions. Liquid applications of the suitable pesticides according to directions only when needed are generally more effective than aerosol sprays or granular treatments. We spray on cloudy days, evenings and after plants have been watered to avoid damage to plants.

VARIETIES for cool growing areas and green houses are Cymbidium orchids, some Dendrobium and Paphiopedilum varieties, Masdevallia, Odontoglossum and Miltonia orchids. Grow Cymbidiums outdoors from May to October, feed them weekly, but with low nitrogen food from August to February and less often in winter. They can be grown in bright sunlight if kept moist and misted often on hot days. We shade them with 55% shade cloth. Cattleya, Paphiopedilum and most species orchids can be grown outdoors as well in Illinois, but these should be protected from bright sun, drying wind and extreme temperatures. Plants will develop stronger growths with summertime outdoor growing if the alternative in a less bright room in the home, or a basement growing room. Phalaenopsis and mottled leaf Paphiopedilum orchids are warmer growing, and like to remain indoors here. They are ideal for home growing in areas where African violets or house plants thrive. Blooms last for many weeks, and plants can bloom more than once a year. Vanda and Dendrobium phalaenopsis orchids are especially happy with high humidity and stuffy hot climate while the summer growing season allows for their rapid growth.

HOME GROWING of an orchid plant is rewarded with great pride of accomplishment when blooms develop. Phalaenopsis and mottled leaf Paphiopedilum are the easiest to flower with African violet type of care and climate. Their growing under lights in basement rooms is possible. Plants can be in flower for many months, and may bloom more than once a year. Phalaenopsis will re-bloom on old flower stems when these are cut above a node at 1/2 of the total stem length.

Cattleyas, if grown in homes, should be kept at 60-65 degrees F. at night and should be grown outdoors from June to September.