Q: The flowers on our Phalenopsis orchid are mostly gone and we are left with five flowers and very long stems and roots. Should this be repotted and cut back with new soil? Can it be taken out to a sheltered patio with partial sun and much light?
David Chia
A: Orchids are usually kept in the same pot for two years before repotting. Normally phalenopsis has surface roots. But if there are many roots and theyre wandering down the side of the pot, it should be repotted.
Repotting should be every two years because the old bark begins rotting. The main element in the potting mix is orchid bark. You can buy this in garden centres. A little spaghnum moss is sometimes added to the bark but isnt really necessary.
Orchid bark is used because Phalenopsis orchids need exceptionally good drainage. But they also need daily watering and misting because their roots are used to humid conditions in their native tropical forests where they grow on trees.
Overwatering kills orchids, so be discreet but frequent in watering. The flower stems should be cut down to the base once the flowers have faded. A position outside on your balcony could go wrong.
Phalenopsis likes day temperatures of 20 to 25°C and night temperatures around 15 to 20°C day and night temperatures will often be too cool for your orchid.
I wonder which way your balcony is facing. Partial sun is okay if its the gentle morning sun. But sun from the west or south can be far too hot in summer for such a shade-loving orchid. Your fertilizer should be diluted to one-quarter of the recommended strength. Phalenopsis roots are very sensitive to salts and dont demand heavy nutriments. Its also best to fertilize only once every two waterings.
Anne Marrison is happy to answer garden questions. Send them to [email protected].
