Many people think that growing orchids of any type is difficult, and can only be accomplished by a specialist. This is a fallacy as most people can grow orchids if they give them the right climate. Orchids range from the tundra to the equator, living in most habitats. Therefor, some orchids must grow in every type of climate. Most epiphytic orchids are easy to grow, although they are slow. To begin with, take note of the climate where these plants grow in nature. Mostly they grow in rainforests, with the maximum volume of species growing in the cloud forests inside the tropical belt of the world. These plants often receive moisture throughout the year. Other orchids survive in monsoonal areas that are dry for part of the year, but in the summer rainy season they can be wet for weeks at a time. These two divisions of the climate are most important, as many orchid species such as Cattleya, Dendrobium, and some varieties of Odontoglossum need a winter rest period, where they can stay dry for longer periods. Orchids such as Cymbidium grow in cool climates, but species of Phalaenopsis prefer warmer climates, and like it moist throughout the year, as they do not have a rest period.
All new orchid hybrids are registered with the R.H.S., giving details of both parents, date of the first cross, name of the person who first flowered it, and the name given to the hybrid. With this information, the original parents can always be traced.
When a cross is made between two orchid plants, a seed pod is produced with up to one million seeds inside. The many plants grown from this pod have at least a slight variation from each other, although they all carry the same hybrid name. Every time this cross is repeated, they too must carry that same hybrid name. If a very special plant of extra beauty is singled out, this one may be given an extra name to identify that particular clone.
All hybrid orchid names in this book have an x before their species name. Also, this species name will begin with a capital letter. Accordingly, it will distinguish it from the natural species of orchids. A particular clone, which has been registered, has an inverted comma before, and after its clone name.
Although we can hybridise many natural species of orchids together, other species seem incompatible. Though incomplete, below is a list of hybrid generic names that have proved not only compatible, but have become favourite hybrids with many growers. By providing the parent genera, we can see how they have received their colour, shape, and size.
Genera Grouped in Their Aliance
If we want to grow good specimen plants of the Cymbidium orchid, clean out all the dead roots, and leaves when potting up into a larger pot. Any pseudobulbs that are obviously rotting away can also be removed. There comes a time when the plants get too large, and the centre of the root ball cannot be reached without damaging the plant. At this stage breaking the plant apart would be better, and clean each section individually. We can either plant each section back into one container or start new specimen plants again.
Most repotting is done in spring, when the new growth has started, but before the new roots develop. This will give the active roots a clean, and healthy place to get nutrients. Care should be taken at this stage as the new growth is very brittle.
If pot grown, orchids should not have other vigorous plants grown with them, as plants like ferns, clog up the potting medium. This will restrict air movement around the orchid’s root system.
At this stage, a good knowledge of the root types is required. These fall mainly into three types: thick roots that belong to Cattleyas, and Zygopetalums, thin roots as in Odontoglossums, and Miltonias, also aerial roots on such species as Rodriguezias, and some Vandas. Each should be treated differently.
To begin with, let us pot up the thick root types. In their natural habitat these roots cling to their host’s tree bark, often spreading out over a long distance to gather moisture, and nutrients. These roots need a coarse potting mixture that imitates the surface on which they grow in nature. In the past, many different ingredients have been used, such as granite chips, osmunda fibre, hardwood chips, and many others. Today, most growers have come the full circle, and gone back to the bark of various trees, sometimes with washed lumps of charcoal. To fit it into a container, such as a hollowed out log, basket or pot, it must be broken into chunks. Common sense tells us that very small plants going into very small pots or tubes should have a very small grade of chips. Ground chips that pass through a kitchen sieve with 2-millimetre (1/16-inch) holes can be used. Nevertheless, any particles that pass through a flywire sieve, is only dust, and should not be used in the mixture. For pots between 6, and 8-centimetres (21/2, and 3-inches) a grade of 7 to 8 millimetres (1/4-inch) is useful. For larger pots, a correspondingly larger grade should be prepared. The size of the bark chips can then increase with the size of the container. Always remember to sieve out the dust from the bark chips, as this dust will wash to the bottom of the container, and becomes waterlogged. Boiling bark chips to rid them of surface acid, and fungi is also safer. Also, not burying roots that grew on the surface of the old mix is important as they will die.
Next we will tackle the fine root types. Besides clinging to their host’s bark, many roots are aerial. Seemingly, they have no particular direction of growth, making little contact with the host tree. Being aerial, they usually collect falling leaves, and other debris, from which they feed. Grade the size of the potting mixture pieces the same way as we did for the thick root types. Only, this time we can place on the surface some leaves from deciduous trees. When we add leaves always mix in some twigs to keep the compost open, and free draining. Leaf-mould is sometimes used when potting Odontoglossums, and some Dendrobiums. Although many growers do not recommend it, it can be useful to their growth. Soft material like live sphagnum moss is useful for plants like Odontoglossums. However, place the soft material on the top of the chips, this way the roots grow through moist material, and it does not get compressed. Sphagnum moss is a good indicator for the potting mixture. If the wood chips or the water is too alkaline, the sphagnum moss turns yellow. If it turns dark green, it may be too acid. Also, it is a good indicator of dryness as it shows signs of drought long before the plant suffers. Again, do not bury any roots that were not under the old potting mixture.
Now we can work on the orchids with only aerial roots. Such plants as Rodriguezia, that have masses of aerial roots, cannot be placed in potting mixture. Placing them into a wooden slat basket is simpler or in a split hollow log with holes in the base, then hang it up. They can also be tied to a piece of driftwood using fishing line. If nylon fishing line is used, we have to be careful not to tie it too tight or it will cut through the plants tissues. Attention to the roots of these plants is much simpler, and quicker than the other methods, as we have no potting mixture to make. Also, this method can look more natural, and attractive.
Most types of sympodial orchids will grow easily mounted on an epi-log either made of wood or tree fern fibre. Some species are better off grown this way, as their pseudobulbs are spaced wide apart on their rhizomes. Usually, it is as easy as tying them to the epi-log, and placing the plant in the correct amount of light. Nevertheless, some orchids need a little sphagnum moss underneath their body to give them more moisture, and encourage the roots to grow. This method gives them superior drainage, and a more natural look.