Growing Native Dendrobiums in Melbourne – well let me start with this, Melbourne is not Sydney or Queensland! May seem an obvious and somewhat irrelevant comment but the thing is most articles written about growing native dendrobiums are written in Sydney (or greater NSW) the reason being more people grow them in Sydney than Melbourne as the climate is milder and most dendrobiums will grow superbly in their back yard either under a tree or in a shadehouse.
If you read many articles about growing native dendrobiums or native orchids generally they will talk about growing in shade houses or bush houses – this type of culture is not appropriate in Melbourne (in my opinion anyway)- lets looks at why
Temperature – if you look at the temperature of Melbourne vs say Sydney and Brisbane there is a huge difference in Spring and Autumn, critical periods for the growth of Dendrobiums, Melbourne temperatures are colder but also more volatile than further north. As growers in Melbourne we need to lift the average temperatures during Spring and Autumn as well as trying to smooth the temperatures. (ie lift the temp of the coldest days)
Humidity – Melbourne is much drier year around than further north, we need to constantly lift the humidity of our growing environment to match Sydney, Brisbane and the areas native dendrobiums grow.
The other reason I would never grow my native orchids in a shadehouse is water – I want to control when my orchids are wet and when they are dry, especially in the middle of winter and spring when miserable cold days are also often wet in Melbourne – not a good mix for health happy orchids growing at their prime….
Beyond this some basics we follow; (this should be similar in most areas)
- We re pot every 2 – 3 years with 2 years being most common, our mix deteriorates after that. Native Dendrobiums seem to enjoy a re-pot so no big set back.
- We use a slow release fertiliser as well as foliar applications when the orchids are in active growth, the foliar feeding seems particularly important for young plants.
- Light levels are important and vary from plant to plant and cross to cross, if your plants pseudo bulbs and/or leaves are growing our horizontally and/or are very dark green your plant is not getting enough light, plant growth should be fairly upright with leaves a “mid green” sorry not a super explanation – you will get a feel for it over time. We grow under 30% shade in winter in Melbourne as the days are short and gloomy, adding a peice of 70% shadecloth once we notice the plants starting to yellow slightly (around end October / start November – varies year to year depending on the weather) – we take it off once the miserable weather sets in in May.
We pretty much water in the same way year round – that is we water when the plants are totally dry or close too while also trying to avoid watering on the coldest days even if this means they sit dry and extra day. At the height of summer we will water in the afternoon and at all other times in the morning. (ie in summer this will generally be every 2-3 days or even every day in Feb, while in the depth of winter it might be 10 days between water)
Certainly hope that helps – if you have any questions or want to tell us about your conditions then please comment below.