After a week off for the British Grand Prix, I am delighted to see the first of the dahlias coming into flower, both in my own garden and the ones we are growing for our Dahlia festival at Pashley Manor. This week’s email is written by my son Christopher, I hope you enjoy it.
While they are easy to grow, there are one or two things to remember, and some common pests and diseases to watch out for.
Debudding For taller dahlias, some light pruning is needed. Around now, as groups of three buds start to develop, the two outer ones should be “pinched” off. While it may seem counter-intuitive, doing this for the next few weeks will cause a much more pleasing display over the coming months. It prevents the flowers being covered by too much foliage.
Feed Dahlias can be fed with a liquid nitrogen fertilizer but do this sparingly. Over fertilizing can cause the plant to become too leafy.
Slugs Dahlias, like many other summer plants, can be susceptible to slugs. Fortunately, this is a relatively easy problem to deal with. I have found organic slug pellets and nematodes to work best.
Mosaic virus This usually presents itself as yellow veining on the leaves. The affected plant(s) should be removed and destroyed to stop the virus spreading.
Grey mildew or smut Common later in the season, powdery grey-white mildew on the leaves, or small yellow spots. Both can be remedied early on by applying a general purpose fungicide.
Leafy Gall Although rather uncommon and caused by bacteria, gall appears as uneven swelling on the stems, which eventually wither and die. Again the solution to this is to remove the affected plant to stop itt spreading.
Bloms Dahlias can be seen at Pahsley Manor from the 7-17th of September.
Enjoy your garden,
Chris Blom (the younger)