Cultural Notes – Dendrobium & Sarcochilus
The popularity of Australian Native Orchids has grown dramatically in recent years. New cultivars have provided growers with a broader range of colours and styles that are easy to grow and flower.
Environment. Found growing wild in most areas on the east coast of Australia it is easy to provide suitable conditions in this area. Dendrobiums prefer bright filtered light, 50%- 70% shadecloth is ideal, or a tree or similar screen allowing dappled sunlight is perfect. Sarcochilus are usually found in heavier shade areas, about 90% shade and somewhat higher humidity than Dendrobiums is beneficial.
Temperature. New South Wales coastal temperatures are OK, good air movement is important, especially during very hot or cold periods so natural air flow should not be impeded. Sarcochilus enjoy temperatures up to 30°, over this try to minimise maximum temperatures, by providing more shade or air movement.
Watering. Perfect drainage is very important, many Australian Native Orchids grow on trees and dry off quickly after rain. Water thoroughly then allow plants to dry out completely before rewatering. Water regularly in summer, sparingly in winter. If you receive regular winter rain, a solid roof over plants may be necessary to control watering in cold weather.
Compost must be free draining. OrchidMate Coconut Husk Chips or treated pine bark is ideal. Some growers like to add 10% coarse perlite, gravel or styrene to the mix. Adding graded charcoal is also popular. As a guide, use medium chips in 100mm pots, large chips in 150mm pots & extra large chips in 200mmm pots or bigger. If established in the garden, a gravel bed under the plant will help with drainage, or attach firmly to a tree or rock and tie a pad of coconut fibre or similar over the root mass.
Repotting. Dendrobiums are best done soon after flowering, at the beginning of the growing season. We leave Sarcochilus till March/April after the worst of the hot weather has past. Sarc’s grow all year, but experience most growth in this area during Autumn/Winter. Ensure pots have adequate drainage and are just big enough to contain the root system of the plant to be potted.
Fertilise regularly, especially during the growing season, using a soluable fertiliser for flowering plants, low in nitrogen and high in potassium. Plants will benefit from an occasional dusting with Dolomite.
Pests & Disease. Generally hardy and resilient, Australian Native Dendrobiums and Sarcochilus can sometimes be attacked by scale, aphid or spidermite. Treat with a recommended insecticide such as Rogor or Pest Oil. Fungal infections are rare provided good air movement is maintained during wet weather. Use Mancozeb or lime water for leaf infections & Yates Anti Rot will prevent bulb rot. Dendrobium beetle can be a problem during the warmer months. Beetles are easily caught or spraying with Carbaryl is very effective.
Tinonee Orchid Nursery