HOW TO GROW ORCHIDS IN GREENHOUSES
Orchids are perennial plants belonging to the family Orchidaceous and are generally referred to as epiphytes (that is, they grow on other plants only for support as they cause no harm nor derive nutrient from the plant). They are nonwoody and basically manufacture their food by themselves or feed on dead organic matter. They are also considered to be the largest family of flowering plants in existence. There are several varieties of orchids growing well in different locations of the world under different weather conditions. The diversity in their ability to adapt to any growing environment they find themselves is admirable and this makes it easy to create a suitable growing environment for them especially in a greenhouse. Most growers find orchids difficult to grow and rightly so, many varieties of orchids can prove to be truly difficult to grow, and even while some may grow from seed level, keeping them alive is a different issue entirely.
Orchids are actually of two categories and each grows in a different way. The first category includes orchids with a single stem having leaves oppositely arranged along the stem. These orchids are called Monopodial orchids. They have specialized lateral growth patterns, and develop pseudobulbs which store water and nutrient for the plant’s survival. Examples of orchids under this category include dendrobium, cattleya, etc. The other category includes orchids classified based on their habitat. Some orchids exist in the tropical region, some in a warm climate, and some others in the cloud forests. Their habitat determines the required temperature range, light intensity and moisture content for their successful growth. As earlier stated, there are several varieties of orchids and while there is no general rule that exactly works for all the varieties, how each variety looks like will give insight on the growing environment needed. Examples include when the:
- Orchids have few leaves; it means that they probably require much exposure to light
- Orchids have large pseudobulbs; they do not need much watering and should be watered less frequently
- Orchids have no pseudobulbs; they will require frequent watering or better still, grown in a soil with high water retention ability.
For the successful cultivation of orchids in your greenhouse, the first thing is to choose a variety that thrives in the growing environment you can provide in your greenhouse. Purchasing a more matured plant rather than seed starting can also help in successful cultivation.
Conditions for Growing Orchids Successfully
1.Lighting: this cannot be overemphasized as orchids are known to be light-demanding plants. Be ready to supply an artificial lighting system in your greenhouse and the orchids should not be far away from the provided grow lights. The new full spectrum grow-light bulbs are a good choice for the artificial lighting system in your greenhouse.
2.Growing medium: the growing medium used to grow the orchid plants must be able to supply good aeration and also good drainage. Typical examples of medium to use include peat moss, rock wool, perlite, fir bark, coconut fiber or a combination of these mediums. Most of the growers that have successfully grown orchids are known to have used fir bark as a growing medium but doesn’t mean it’s the only suitable growing medium. It all depends on the variety of orchid being grown.
3.Watering: the major reason for the unsuccessful cultivation of orchids is mostly as a result of too much watering. Most orchids can easily survive a lack of water but cannot survive in a flooded medium. waterlogged soil medium limits the rate of air circulation and therefore stunts the growth of the orchid plant. Allow the soil medium to dry before replenishing with water. Orchids may be difficult to grow but with the right growing condition provided, its successful cultivation is very much possible.
4.Humidity and Fertilization: most greenhouse gardens growing orchids uses a humidifier to ensure the right humidity level required by the orchid plant in the greenhouse. The nutrient in the growing medium is usually not sufficient to keep the plant alive and therefore, there is a need for fertilizer application once the plants are already actively growing. A common fertilizer application among orchid growers is the 30 – 10 – 10 fertilizer.
5.Container: in a situation whereby the orchid plant requires being repotted into another container after the root system has been fully established, it is advisable to use small plastic containers first for easy detachment and good drainage. Not all orchid plants will require being transferred though and it is important not to transfer the plant unless it is required and necessary. Avoid interrupting the growth of the orchid plant by unnecessarily repotting, this may render the plant dormant for a long period before the plant starts to grow again. Repotting the plant becomes necessary when the plant’s root system starts to outgrow the container, or when the growing medium is failing and there is consistent poor aeration.
4.Seed starting: as we have established earlier, that growing orchids from seed can be somewhat difficult, it does not mean that it is impossible. To successfully grow orchids from seed, it is extremely important that the growing condition provided is germless and the seed is propagated in a jelly-like gelatinous substance containing growth hormones coupled with the needed nutrients. You should keep in mind that orchid seeds generally take time before they germinate, so ensure to have enough patience to tend to them while they quietly grow. It usually takes about 5 to 8 years before an orchid plant propagated from seed blossoms and sometimes earlier than 5 years.
If you are ready to grow your greenhouse orchid garden, below are useful additional information you might want to keep in mind:
- Orchids are known to produce more hybrids than other plants
- Your orchid plant can bloom within a year or less if not cultivated from seed
- Orchids generally do not appreciate the unnecessary change of the growing medium. Practice repotting only when it is necessary.
- These varieties of orchids are great choices if it is your first try out with growing orchid plants:
- Paphiopedilum – requires a temperature range between 55 – 80ºF and relative humidity of about 50 – 60%.
- Cattleya – requires high light intensity, also temperature range should be between 60 – 90ºF and maximum relative humidity of about 80%
- Phalaenopsis – grow in a temperature range between 60 – 80ºF and works best with fir bark as the growing medium. Relative humidity should be between 40 – 70%.