Dahlia leaf problem

Hello,

I'm hoping you can help me. One of my dahlias is having a bad time after growing to a healthy height. I think that it's maybe a sap-draining pest but I've done a lot of google searching and I can't find any similar images.

This is the first time that one of my dahlias has failed to flourish so I'd welcome any advice, especially if I can do anything to rescue it.

Many thanks in advance, Chris

 

Hello Chris and welcome to GC forums
It looks like aphids to me, here's a video on it, the guy in the video is treating houseplants but can do it with outside plants.

Part 2

 

Sounds like a lot of soap to me compared to the amount of water.

 

Many thanks for your quick reply. I'll certainly try this. Would you recommend cutting off the damaged leaves or even pruning back to the unaffected parts of the dahlia?

 

I grow a lot of Dahlias and the damage could well be caused by Earwigs. As far as Earwigs are concerned Dahlias are nectar to them. As I don’t like to spray much, certainly anything harmful to bees etc I do what my old dad did which is to half fill small flowerpots with hay if you have it or dry grass clipping or anything really which is dry and could make a sort of nest. Place the flowerpots upside down on canes in amongst you Dahlias. In the morning, earlier the better tip the flower pot out and be ready with your size nines to squash them as Earwigs will have used the nests over night and attempt to escape at speed. Quite a satisfying process once you get adept at it! Re the damaged foliage. You can either leave it or remove if it is cosmetically bothering you. The areas will continue to grow but be distorted if left.
The plant looks good and healthy so not that serious. You will still have plenty of time to enjoy your Dahlias this season. Despite living in Scotland most years I still have Dahlias flowering when the local person comes to collect for Poppy Day. They always remark how lovely it is to have lots of flowers at the end of October.

 

Thank you all, this is all incredibly helpful. I'll try the soap and earwig capture method at the same time

 

He's done it on his own plants and it works.

Have to do it more than once like in the videos.