Plant Doctor Archive

Spotty dahlias

My problem is that my dahlias have a blotchy look on their foliage. I have a large collection with many beautiful bloomers. Some are very old and special, while others are recent purchases. But mostly I've swapped tubers with friends and family to gain different ones.

I mulch in early growth with grass clippings and at the end of the season, after cutting back, put a layer of either sawdust or barley straw to keep frost away. At odd times they get a "dose" of rotted calfhouse litter.

I'm not allowed to water any of my garden, as we live on a dairy farm and the cows come first.

Recently I was thrilled to have a seedling develop to bloom as a wafer lily form in a rich brick colour. When you have the patience to set seeds and let them grow it's magic!

IT sounds like you have leaf spot on your dahlias. Spray with Fungus Fighter or Greenguard at regular intervals until the problem has cleared up.

Reproduced with permission from the former Weekend Gardener magazine. The views expressed here are not necessarily those of the RNZIH.