Nurtured in Norfolk’s gardening expert Martyn Davey answers all your questions and gives his top horticulture hacks.
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I have a problem with my orchid it has started to die even though it is in full flower, the leaves have gone brown one by one and now there is only a dot of green in the centre of the leaves. This orchid was first purchased from a reduced to clear section of a large supermarket and has been part of the family for around 5 years now and has never really stopped flowering. Has it just flowered itself to death or is there something I can do to save it? It has tap water weekly and I rarely remember to feed it although it has been fine until about a month ago.
There is not a lot to go on as to what type of Orchid this is although I suspect it is a Phalaenopsis or moth orchid as these are commonly sold in supermarkets and flower for months at a time making them great value even if you treat them more like a cut flower than a pot plant. Although I fear this advice may be too late for your particular plant please do purchase another and try again as five years is a good amount of time to keep a moth orchid going if you have not fed it or re-potted the plant.
Ensure good light levels in winter, as these are essential to encourage flowering. An east or west facing window would be ideal. Move to a shadier spot in summer and protect from direct sunshine as this will scorch the leaves and can cause them to go brown and die. Occasionally wipe off the dust from the leaves with a damp cloth, as dust will block light from reaching the foliage.
Moth orchids grow best in warm environments and will thrive in a place with central heating. Provide night temperatures in the range of 16-19°C and day temperatures between 19-30°C. Avoid draughts and fluctuating temperatures. Phalaenopsis produces flowers that last about three months (sometimes even longer) at any time of the year. Once the flowers have faded, cut the flowering stalk back to just above the second node (joint) visible beneath the spent flowers. A new flowering side shoot may develop. If a plant is large and healthy but does not produce flowers in a reasonable time, then reduce the temperature by 5°C for four weeks, and a flower spike will usually develop.
Water Phalaenopsis regularly throughout the growing season. Reduce watering slightly during the winter. Always keep the foliage dry, taking care not to splash the leaves when watering. Do not let the roots dry out completely, but avoid letting the plant sit in water. Mist the plant lightly with just plain water in summer tap water can leave lime scale marks on the leaves. Feeding can be done regularly in the growing season, almost every time you water, but plants do need the occasional ‘flushing out’. So, apply proprietary liquid orchid fertiliser with three waterings, but use only plain water (with no fertiliser) every fourth watering to ensure that any potentially harmful accumulations of salts are leached from the compost. Feed sparingly during the winter months.
Phalaenopsis can be re-potted at any time of year, clear pots are useful as an aid to watering as they enable you to see if the compost is still moist below the surface. Phalaenopsis’ roots are also attracted to the light and prefer growing in clear pots.
It is time to re-pot your plant as soon as it has become too large for its pot or when it has been in the same compost for 2 years. In the case of Phalaenopsis re-pot when the roots are active and showing green tips. Always use proprietary orchid compost. Remove the plant from its pot and work at the rootball with your fingers, untangling the roots and removing all of the old compost maintaining your orchid’s roots in good condition is essential to its successful cultivation. Snip off any diseased or dead roots with sterilised scissors or secateurs. These are brown, mushy, shrivelled or hollow in appearance. Shorten the remaining healthy roots that should be white and firm, back to around 12cm.
If the roots comfortably fit into the old pot, then reuse it. When using a larger pot unnecessarily, the compost will stay wet for too long causing roots to rot. Hold the plant at the correct level in the pot and fill in the spaces around the roots with fresh compost, gently firming in as you go and ensuring the compost is pressed down firmly around the perimeter of the pot, so that finally, when the plant is lifted by its stem, the pot and compost is lifted with it and does not fall off. Loose compost will cause the plant to be unstable and damage the new root tips, stopping them from growing. Don’t bury the roots that are growing out into the air, as these will rot if confined in the compost. If the plant needs the support of a cane or two until its roots establish in the pot, insert them now. Finally, give the plant a thorough watering ensuring all the rootball is moistened. Drain the plant thoroughly and do not allow it to sit in water.
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