Andrew runs Orchid Alchemy and concentrates on cooler growing species and hybrids, so is well placed to talk about the subject matter. Much of this is probably common sense and straightforward, but we are all a bit naive when growing orchids and a few handy tips can come in useful. There are a few general areas that complement the budget theme. These are reduce costs, insulate, rationalise plants, cull/reduce collection, or grow hardies or near hardy orchids.
In reducing costs comes controlling costs through better management of resources. Thermal density is a useful technique that is much underused. This means using material such as ash based concrete blocks to absorb daytime heat, which then can radiate it out during the cooler nights. A good thermostat is a sound investment to ensure that your heater isn’t creating more heat than required – an extra 1C costs a small fortune. Can you split your greenhouse into different heat zones? Just having a cold part will save cost. Alternatively could you grow the warmer plants in the house somewhere?
If you have a greenhouse, is the location correct? Full sun in winter is the best target with the ridge running east/west. This may prove too warm in summer though, and a large degree of shading will be required. Traditional greenhouse construction of wood and brick is still the best as they are warm compared to aluminium. If the walls are dug below ground level this also helps. Polycarbonate sheeting is a newer material, and has benefits. Inside the greenhouse, doors and vents should be well insulated for especially cold nights. Thermal screening such as woven aluminium is beneficial to use as required. Benches should be constructed of concrete blocks – painted a dark colour to absorb heat. Water tanks will also absorb heat, as well as ensure that it is at room temperature when used. In the home, LED lights and growlights will suffice, as would wardian cases. Avoid south facing windows in summer, and other direct heat sources such as radiators and televisions are best avoided. Growing in the home is more specialised, and drip trays become essential.
Can other structures be used? Tomato houses will suffice in summer for many plants, and maybe a conservatory will suffice in winter. Houses have more stable heat due to their construction methods, whereas greenhouses are more extreme, more quickly.
With hundreds of thousands of species and hybrids to choose from there is great variety to choose from. Most are tropics, but come from cooler altitudes, and this is often overlooked when growing the plants. It may be that overheating is used for a large part of the collection. How cool is cool? Most books say a minimum of 50F as a general consensus, however a lot of them naturally drop to near freezing such as Australian Dendrobiums. They will however need a daytime rise to this figure rather than a constant low temperature. Some cool growing species are in reality frost free, so would manage with a minimum of 5C. This includes many terrestrials, which just need to avoid winter wet such as Habenaria, Stenoglottis, Pleiones, Disas & Calanthe.
True Hardy orchids need no heat, and can provide a range of spring and summer colour. These have become more available in the last few years. Many of these will self seed, and costs can be reduced by swapping with friends for other species or hybrids. Most Dactylorhizas are shades of pink, but alba forms are common, and in Dact. sambucina both red and yellow forms exist. Cypripediums are fully hardy and have a range of colours as well as some being quite tall. Epipactis is a genus that bulks up well, and very available. Epcts. royleana is a good red colour. These need to be kept damp even when dormant as they don’t have tubers. Calapogon is another genus that needs to be kept damp. Spiranthes is a genus of chalk lands rather than the bogs that others commonly thrive in. Many other genuses are hardy, and are too many to mention. Small plants are often cheap to buy, and can come via mail order. Seed grown plants are better than divisions as they will become specimens more quickly as well as aid biodiversity.
In summary, don’t waste heat. Only heat what you need to heat, and make the heated space to fit the plants. If possible, rationalise plants to a single low heat category, and use other places in the home for warmer plants. Grow outdoors with just a bit of extra care on raising beds to aid drainage. Research your plants to get a proper understanding of their requirements so that you don’t waste money. Do all this and you can enjoy growing orchids for just a low outlay. After a few questions on compost for hardy plants, a hearty round of applause was given.