I have had an issue this year with several of my dahlia flowers being abnormal. These are on plants that grew from tubers that I overwintered from plants I grew last year, and have grown these varieties for several years with regular looking flowers on them. This year I used fresh potting medium in my containers, and have been growing in these types of containers successfully for at least a decade.
It's not every flower on each plant, but it does seem to be that majority. Specifically, my collarettes have a double row of petals. 'Appleblossom' is super yellow, with very little of the pink. 'EZ Duzzit' is very red and yellow instead of orange and gold. 'Giraffe' has very little horizontal barring on the backside of the petals, with lots of vertical striping instead. 'Steve Meggos' and 'Vassio Meggos' aren't creating the nice globe shape with the petals folded back to the stem, while 'Louis Meggos' is.
In contrast, I have varieties that are just rockin' it. All my waterlily and formal decorative types, as well as my only single.
Anyone have any suggestions for what could be causing these odd flowers? My guess is some kind of stress, but not sure which (chemical, heat, fungal, etc.), so I don't know how to prevent it in the future. Thanks for the help!
