Here in Belmont, New South Wales we have a relatively mild climate. We are situated between the lake and the ocean and in the winter the temperature does not vary below 6°C so we do not get frosts.
During a growing year we consider the weather to be of two climates: winter and summer. Considering the year in this way simplifies the way and times we vary the level of light our plants are exposed to.
In the winter months, April through October, the plants are kept under a single layer of shade cloth which ensures they have plenty of light for growth and spike initiation without risk of damage from high temperatures.
However during the summer months we add an addition one to two layers of shade cloth, weather dependent, to prevent damage from high temperature exposure. Another issue the plants can face during this season is dehydration. Sarcochilus orchids don’t have a bulb system and they can rapidly dehydrate during hot whether conditions which leads to the loss of plants, or the additional stress can prevent flowering.
The western side of the shade house is covered in to protect the plants from hot westerly winds which occur in the summer. This enclosure also helps protect from cold winds in winter. The floor of the shade house is mostly covered in weed mat which is watered down to help increase humidity within the shade house.
The benches used to hold the plants are of simple construction: a galvanised pipe frame with a bench top of weldmesh. This allows for easy cleaning and water run off is no issue.
Pots and Potting Mix
We use standard black pots for all our Sarcochilus growing now. Previously, we used squat port pots but found the roots were soon growing out of the bottom. If the plants grow out and attach to the surface on which their pot is sitting, typically a foam or black plastic tray in our case, the only way to remove them is to damage the roots. A situation which is obviously undesirable. Similarly if the plants are growing on our metal benches and their roots grow out, the root tips will die off causing the plants to divert more energy in to producing more roots. Thus, we found putting the plants in taller standard pots it takes the roots longer to grow out the base and they seem to flower quicker.
There are many different mixes used by growers throughout Australia. The mix we use – which works best for us here – consists of Orchiata bark and perlite in a ratio of 5 parts 9-12mm bark, 5 parts 12-18mm bark and 1 part perlite. This is a good open mix which allows water to run through freely but enough water is retained so watering is not required as frequently.
We use mounts made out of gutter guard and mesh port pots for most of our Sarochilus species (falcatus, olivaceous, spathulatus, dilatatus, Plectorrhiza tridentata, etc) with good results. Due to the way we mount the plants it is unnecessary to foliar feed.
There are other mounts which can be used with good results such as cork, tree fern and old fence palings. However, with these you need to foliar feed.
In summer, watering occurs every 2-3 days depending on the heat and winds. To check when a pot needs watering look at the potting mix through the holes in the base of the pot, if it looks damp don’t water. After a while it is possible to tell whether a pot is dry by its weight. Pick up a dry pot, water it and then pick it up again. You can soon tell the difference.
In winter months, we find watering once or twice a fortnight is sufficient.
Watering occurs by hand with a hose around 9am. This ensure the plant leaves are dry for night time. If the plants are not dry and it turns cold plants can get bacterial rot which marks the leaves with black and brown spots. These are usually shown as we under the leaves and if it goes to the center it may kill the plant.
Orchids are minute feeders. Every orchid grower has his own method of feeding as there are a large range of fertilisers suitable for orchids.
Our method is simple. We only feed with Blood & Bone with potash. This is done when we re-pot plants, and again one month before flowering. To do this we sprinkle the Blood & Bone on the top of the mix and water it in straight away. The plants take it when they want to feed.
The Blood & Bone we use is the Yates Professional Blood & Bone as it now has the potash added which gives the plants a complete fertiliser.
Pests and Disease
The main pest we encounter are scale and mealybugs. Regular checks need to be carried out, especially under the leaves. These pests can be cleaned off with a methylated spirits or some of the pest oil products. If the scale is bad there are specific chemicals that can be used but all the chemicals must be used with caution as they are generally poisonous. Getting rid of ants also helps get rid of scale.
Bacterial rot is one of the main diseases. It shows up on the leave as black and brown wet spots. They continue to grow and, if not attended to, can kill the plant. The rot happens mostly in winter when the leaves are damp and the night turns cold. There are chemicals available which can be used to help control the disease.
Disclaimer: The information provided above is of an advisory nature and may not be applicable to all climates. Fitzsimmons Orchids will take no responsibility for the results of your growing practices.