These notes are intended to give an indication of the various orchid genera, species and related hybrids that can be grown in the Manly Warringah area of Sydney, (North Shore) Australia, with only 50% shadecloth for protection. Bring the plants inside when in flower to prevent spotting.
During the last 15 years my wife and I, since we have been infected with the orchid bug, have grown various orchid species and hybrids. We feel confident that if you look at the conditions you have in your area and pot your orchids with media that will suit those conditions then you should have no problems growing the orchids listed below:
There are others, however, as well as hybrids and intergenerics of the above. I have included only the ones we have grown well in our conditions. If you stick to some basics you can grow most if not all of the above into glorious flowering specimens.
You require three elements to grow your orchids well
1. Light or shade, which is the lack of light. Depending on the plants you are going to grow 50 % shade cloth is all you will require except for the following. Cymbidiums and their hybrids, Sophronitella violacea, Bifrenaria harrisoniae require more light from no shadecloth to maximum of 30%. On the other end of the scale most of our Stanhopeas, Sarcochilus falcatus, fitzgeraldii, hartmannii, olivaceous, require 70% or more. Look at your plants regularly what are the leaves telling you. Dark green is too much shade, while light green to yellow or 'bronzing' is too high on light. Sufficient light is important for healthy growth and flower production.
2. Air, and air movement is important to your plants, if you have a good supply of air surrounding them you will have a buoyant atmosphere. A good supply of air will also help to keep your plants disease free by blowing away any fungal spores. This also means don't crowd your plants together, give them plenty of room.
3. Water, preferable rainwater, to feed to your plants which should be pH neutral or at least 5.5 to 7.0. Do not let anyone tell you to water weekly or on a regular basis. You should water when the plant tells you it requires it. In summer you will have to water more often than in winter.
You should be able to look at your plants and see what they require. They will tell you what they want in the way of light and water. Do you remember the last time you washed your clothes and hang them on the line? They were soaking wet, yes? If the sun shone and the wind blew they dried in next to no time, right? If the sun shone but you had no wind or the wind blew and you had no sun then it took longer to dry? Well the same is true of your potting mix. If you have a good supply of free air and light then the mix will dry out more frequently. If either the light or air is missing then you will have to adjust your mix, or water to account for this.
A good way to check on how your pots dry out is to soak a pot for up to 10 minutes in a bucket of water, I suggest that this is only done in summer, and take the pot out and drain it. Now pick it up in your hand a weigh it with your mind. Next time you pick that pot up you should know weither it needs water or not.
Your plants can be grown in plastic pots, timber baskets or tied on rafts of timber, cork or tree-fern fiber. The media to hold the orchids in pots can be bark or sphagnum moss. The media is there to hold the plant until it can anchor itself with its roots. The roots need to breathe and take nutrients to the plant. They can be moist but must not become soaked and waterlogged. So have a mix that will allow the roots to absorb water and nutrients but not become stale and excessively wet. Do not over-pot as this will tend to retain more moisture. Allow for a maximum of two years growth and then repot into a larger pot if you intend to grow the plant into a specimen or break up into smaller pots.
Orchids can get by with minimal food. However, I have found they will respond to a regular feeding program by producing a stronger inflorescence, and flowers with better texture and substance. Adhere to the old saying 'weakly weekly'. Use ¼ to ½ strength of the recommended strength of your fertiliser, and flush with water after every 3 or 4 times.
Information is available. Visit your local society and ask questions. Get hold of books and read about the places the plants come from. Thats another reason to belong to a Society, free books on orchids. All growers are only too happy to talk on their favorite subject, (sometimes it's impossible to shut them up). If possible see how they grow their plants, but remember while you are looking at the plants, also look at the microclimate in the area they are growing. Where is the sun, wind and rain coming from? Do they have shade from trees or houses. Is it summer or winter.
For more information, surf the web.
Our block of land faces due north. The shadows vary dramatically from 30º at 12 noon in winter to almost directly overhead at noon in summer. The temperature ranges from 5º C in winter to 35º C in summer with occasional days down to zero and up to 49º C at other times.