Orchids in Semi-hydroponics 

 Information supplied by

Col Dawson

of the Childers Orchid Society



How I Grow My Orchids……..

cols ballsJune 2018

The method I use is known as semi-hydroponics. This method features clay balls in a pot with no drain holes in the bottom. There are several holes in the side of the pot about 25 mm up. This set up maintains a small reservoir in the bottom of the pot.

There are several brands of balls on the market including HYDROTON and CANNA AQUA at prices varying from $25 to $55 per 50 litre bag. It is important to thoroughly clean the balls in water and then clean them again. 

When transferring plants from bark mix to balls it is necessary to thoroughly clean roots of all the old medium and trim the roots. Plants should only be repotted when in active growth (new roots with bright green tips usually). Trim all the old roots back to about 25mm to act as stabilisers, they are going to die anyway and you don’t want a toxic mess in your pot. It will be necessary to support the plant well with a wire hoop. Seal any cuts with Steriprune and spray roots with growth hormone. Keep plants in lower light to promote growth and fertilise lightly, if at all.

Any roots growing outside the pot should be left intact and located inside the new pot.

My fertilising program is mainly Peters Excel (Soft Water Special) @ 1/4 strength every watering, Seasol and fish emulsion once a month, molasses occasionally. I don’t use slow release fertilisers. It is necessary to balance the ph of the fertiliser mix (5.8- 6.2). If it doesn’t rain, flush pots with fresh water once a month.

I currently have about 1000 orchids growing with this method and they include cattleyas, oncidiums, dendrobiums, phalaenopsis, encyclias, vandas and paphiopedilums.

When using this method it is very difficult to overwater. Another advantage is the medium doesn’t breakdown. If you are transferring your plant to a larger pot you only have to add more balls. The consistency of the media provides permanent essential air gaps, which don’t exist in traditional media long term.

For further information ……..

  • Col (07) 41598088








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