This book provides a unique and clear overview of Orchid genera.
Orchids have come to represent happiness, love, romance and mystery. But growing them need not be a mystery, not even for beginners—as long as they use this guide. It gives in-depth coverage of:
- growing media and mycorrhiza
- potting-up and propagation
- watering and fertilising
- temperature control and ventilation
- problem-shooting
This guide gives the home gardener all the knowledge needed for successful orchid growing. Cultivation and care are thoroughly covered with good advice and simple explanations, including descriptions of plant characteristics, flowers and growing habits.
EXTRACT FROM BOOK:
GENERAL GUIDELINES FOR GROWING ORCHIDS
While some orchids require quite specific growing conditions to achieve best results, the following general rules can be applied to many commonly grown orchids:
* Most orchids require a very loose open potting mix. These are commonly made from mainly shredded or milled bark, or tree fern fibre.
* In cool climates never water orchids until the bark on the surface of a pot feels dry. Never let the entire pot dry out!
* When watering with a hose, keep the water jet soft and don't wash bark away from any roots.
* Don't water any orchids with icy cold water. Generally make sure water is at least 15 degrees
Celsius. This may mean filling a watering can with water from your hose, and if its a bit cold, adding some warmer water from a hot tap. Be careful not to add too much hot water!.
* Overwatering is more likely to kill an orchid than underwatering. Keep orchids relatively dry when growth is slow or dormant.
* Generally the thicker the stem of the orchid (often called a pseudobulb) the less often it needs to be watered, unless conditions are very hot and dry.
* Avoid potting up orchids into too large a pot. Pot up a pot bound plant into a pot only one or two pot sizes at a time, no more).
* Keep a look out for pests, in particular, aphis, snails, scale or mealy bug insects, and use control methods as soon as they appear.
* Keep orchids in places where conditions are not likely to be changeable.
- In cool climates, don't place them inside near an open window, where cold draughts of air could be a problem.
- Keep them away from gas heaters or stoves.
- Avoid an inside window sill or bench where they will get direct, hot sunlight. Indirect light is preferred by the majority of orchids.
* Avoid direct sun in the hottest part of the day, and generally provide shade in summer.
* Protect flower buds from direct sun, wind, aphis, snails and slugs.
* Do not overfeed. If in doubt, feed regularly with quarter strength fertilisers.
GROWING MEDIA FOR ORCHIDS
Growing media for orchids is an area of great interest to orchid fanciers and a great deal of experimentation is carried out to try and find the ideal media for different types of orchids. In general growing media for orchids focus on two main groups, these are epiphytic (and lithophytes) and terrestrial (also known as geophytic) orchids. Epiphytic orchids grow on living and fallen trees, and the trunks of tree ferns. Lithophytes naturally grow on rocky outcrops. Terrestrial orchids are those that grow in the ground, although some of these actually grow in leaf litter, rather than in the mineral soil beneath. Some terrestrial orchids will also grow quite readily in soilless mixes.
Epiphytic orchids can be grown on bark, cork or timber slabs. Placing epiphytic orchids directly onto existing trees has been a favourite techniques for many successful growers. It may be worth noting the natural plant to which the orchid attaches itself in the wild, to increase the chance of success (eg is there a preference to Casaurina, Melaleuca, etc). The orchids should be securely tied to the slab, tree, etc., but avoiding damaging the plant, and ensure that the roots are in direct contact with the medium (sometimes called a substrate) they are tied to. The cork, bark or timber pieces can be fixed by such means as simple wire hooks, or durable tying material, to such places as walls, fences, or hanging from trees.
Many epiphytic orchids can also be successfully grown in pots. Both plastic and unglazed terracotta pots are commonly used. The unglazed terracotta pots are especially suited to orchids that require good drainage as they are fairly porous, however, they are also expensive, and can be fairly heavy to lift. Stakes are commonly used, particularly for taller species, to help minimise movement of the plant, which can easily damage the roots.
In general, for epiphytic orchids, mostly inert materials such are used. Many growers commonly use a potting mix that is mostly shredded or milled bark. A good general mix is three parts medium - sized pine bark, one part shredded sphagnum moss and one part perlite.
In Australia national standards have been developed for potting mixes. Properties for orchid mixes are listed under the standards. Many excellent brand names products are available, which comply with these standards. Debco Aust., for example supplies three standard orchid mixes which vary in the degree of coarseness of the pine bark used in each mix.
Lithophytic orchids are usually grown in pots containing a mixture of rocks and bark material. Many lithophytic orchids will adapt to the same cultural techniques used for epiphytic orchids.
The majority of terrestrial orchids can generally be grown in media made up of composted bush debris, peat moss, medium to coarse sand, and small amounts of soil (generally only 15-20% of mix). If the soil you are using is quite sandy then reduce the amount of the sand component. Overall about 50% of the mix should consist of sand. Good aeration is important with the mix being allowed to nearly dry out before watering. Materials such as small gravel, charcoal, and perlite are sometimes added to help improve drainage.
Potting Up Container Grown Orchids
How often you repot will vary considerably depending on the type of orchid you are growing, the conditions they are growing in, and the type of container they are growing in.
* Some orchids, including Cymbidiums and many others, flower best when they are somewhat rootbound. Potting up annually may, in this case, reduce next season's flowering.
* Many plants, however, do their best when they are regularly repotted, as they grow, into larger containers, with fresh potting mix.
* When to repot (season, when pot bound, etc.) is normally carried out after the flowering period.
* How to repot will depend on the species and the material to which roots are attached (bark chips or slabs or soil). The degree of root pruning is beneficial to some species but not all.
* Some orchids have very brittle roots which can be easily damaged if they are potted up...so you must be very careful when potting these.
* Some orchids are easily disturbed by potting. In these cases potting or remounting is discouraged until it becomes really necessary.
In some situations, certain hardy types of orchids can grow rampant, and are such prolific flowering types that they should be divided frequently and the soil or media replenished in order to stop them becoming starved of nutrients and deteriorating.
Mycorrhiza
There is a general consensus that orchids require the presence of various beneficial fungii in order to germinate, live and flower. Orchid seeds are unusual, in that they only contain very small food reserves. When germination occurs this food reserve is rapidly used up, and if the orchid seed has no external source of food, it will soon die.
Recent studies have indicated, that due to the ability to grow seeds in vitro, without fungii, that this may not necessarily be true. It is felt that the presence of these fungii in media are not harmful so there is no need to warrant their destruction. Personal preference may desire the inclusion of these fungii. The easiest way to acquire the fungii for new potted specimens is to remove one or two roots from an actively healthy growing plant and place these roots within the root zone of the new plant, or perhaps to collect water that has passed through a pot containing a healthy, actively growing orchid of the same type, and using it water the new plant/s.