Michael Hare from The Australian Rhododendron Society, Victorian Branch. Michael spoke about rhododendrons, Azaleas and vireyas, presenting a power point presentation of many species, including some growing in his own garden.
Rhododendrons: There are at least 1000 varieties of Asiatic. Native of South East Asia, Japan and Nth America and China. They vary from small plants to large 20 metre shrubs. First introduced into Europe in 1600s, where hybridisation followed rapidly and continues today. Present Australian hybridisation emphasis is on early and prolific flowering, with pest tolerance. This was required because Europe bred plants flower in cooler months, when plants first came to Australia they flowered in summer and died early.
Azaleas: Native to South East Asia, China, Japan and Nth America. The four main species of azalea are: satsuki, gumpo, indica and kuome. They are very easy to propagate and grow. Deciduous azaleas are predominately in the yellow/orange range of colours.
Vireyas: Native to the islands north of Australia. There about 150 varieties in Papua New Guinea. First introduced in the late 1800s and will grow well in temperate conditions. Some vireyas will flower twice a year.
Propagation: Best grown from cuttings, firm wood not hard wood, taken shortly after flowering. Requires moist soil, protection from hot sun and winds, and good drainage. Some sun in winter.
Soil: Well drained acid/neutral (not alkaline) soil. Plenty of decomposed organic matter. Many plants can be grown in pots.
Fertiliser: Regular light dressing of controlled release fertiliser (osmocote) for best flowers. Do not over fertilise.
Water: Should be kept moist, not wet. They will tolerate dry conditions more readily than wet.
Pruning: Light pruning after flowering.
Pests:
- Lace bug. Sap sucking insect. Can kill a plant use an insecticide.
- Thrip. Use insecticide, there may be some resistance, if so use a different insecticide and reapply.
Diseases:
- Root rot, fungus phytophthora is due to plant with wet feet.
- Rust, A fungus which show yellowish blisters. Treat with fungicide.
- Petal Blight. A ground dwelling fungus which causes flowers to droop and turn brown. It is difficult to eradicate, best treatment is to remove and carefully dispose of.
- Powdery Mildew: This appears as a white/black powder on leaves and should be treated with a fungicide.
Where to buy them: The ARS society. Sometimes at Bunnings. Parks Vic. At the nursery in NRG Olinda. Friends of the RBG Melb. Sales in Autumn & Spring. Wishingwell, Silvan. Teslars.
Michael answered questions from members, then raffled a potted rhododendron he had donated.
