Growing orchids
Keeping orchids is easy, but very different from growing normal plants, since most are not grown in soil. Production of seedlings is very specialised and not recommended, so normally you buy either young or mature plants. The problem is to keep them in good condition, so they will flower at intervals.
Miltonia Pansy orchid
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1. Buying orchids.Most commercial orchids come from rain forests, but rain forests are of different types. Thus commercial suppliers divide orchids in to 3 types:
a) "Cool" species come from high altitude cloud forests. Many cannot survive even 20 C. You cannot grow these species, even indoors. They include many orchids commonly available in Temperate countries, such as Miltonia. If the supplier does not say whether it is a "cool" species, then Google it. There is a particular problem with the huge genus of Dendrobium, but suppliers normally say if they are selling a "cool" species. b) "Intermediate" species live at a lower altitude and are happy in temperatures maybe up to 30 C. In the summer, you should keep these indoors in a place that is fairly light. In winter, if you wish, you can put them outside in the shade. This might encourage flowering, in some species. |
Phalaenopsis in chipped bark
Quartz pebbles on Dendrobium pots
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c) "Warm" species come from lowland rain forest. Some can live permanently outside in the shade, even during the summer, providing they have enough humidity.
Both Thailand and Malaysia are big growers of orchids and these are mainly "warm" species, but if you are buying in Europe or USA, you need to be careful. The most common (sold in supermarkets, where it is often unlabeled) orchid is Phalaenopsis, which is "intermediate" and grows very successfully indoors. 2. Growing orchids. Most commercial orchids are epiphytes (grow on trees) and their roots need to be humid, but have plenty of air around them. Thus in soil, the roots will rot. growing media thus need to be well-drained, but hold a reservoir of water. A common growing medium is chopped bark, but since this is not easily obtainable for us, an alternative is small pieces of charcoal. I break up charcoal pieces with a chisel. Charcoal is full of tiny spaces that contain both water and air, so the root is humid but not wet. Note: you cannot use charcoal briquettes (for BBQ's)- when wet, these disintegrate; you need real charcoal. Note in photo, that orchids produce many aerial roots that should be a silvery white when healthy, and that orchid roots are thick and so not easily damaged by handling. Orchids normally come in a small basket. Put the basket in a slightly larger pot with charcoal stuffed in between (see photo to left). Charcoal does not last for ever and after maybe 3 years, it will breakdown in to a waterlogged pulp, which will kill the roots. Remove the plant, shake out the old charcoal, cut off dead roots and replace with fresh charcoal. Water immediately. Charcoal and chipped bark have the disadvantage of being very light, so the orchid is top-heavy and easily knocked over. I put pebbles on top of the charcoal to weigh down the pot. Quartz is particularly attractive, although other rocks such as the black chromite at the back of the photo can be much heavier. A few orchids are ground orchids, e.g. Spathoglottis. These can be grown in normal soil. Some orchids are grown entirely suspended in the air, usually in a basket, e.g. Vanda. These are a problem as they need a high humidity (also Vandas tend to get very big). 3. Watering orchids. Orchids need to be kept humid. Outside orchids may be sprayed with a hose in the evening and with a watering can containing a small amount of liquid fertiliser in the morning. Indoor orchids (where evaporation is less) are very susceptible to stem rot, if you get water trapped in the growing leaf. I put the pot under the tap every 2 days, making sure you do not get water on the plant. The plant, especially any aerial roots, is misted with a sprayer containing a small amount of liquid fertiliser 2x a day. 4. Leaf cleaning. Because the leaves are very long lasting (may have a life of years) and are often broad and stiff, they collect dust indoors. Wipe them with a sponge monthly and at intervals, use a leaf gloss. |