Last year we planted some dill in a corner of the garden. It did OK, nothing spectacular and we largely ignored it, even after it had gone to seed... which then dropped. So we now have more dill coming up in the same spot. But while some of the plants look fine, others are coming up coloured: pink, white, yellow, and a dark, muddy green. I'm wondering if they're coming up with no chlorophyll, but I don't know if they could have reached even the small size they are now without it. Any ideas?
I have no ideas about colored dill plants, but are you sure those are dill? The leaves look a bit coarser than the dill I'm used to. Also, my dill has not sprouted yet, much less grown to the size in your photos. It never survives the winters, but I get plenty of volunteers from seeds.
I am doubtful that it is radiation-induced, but have a read through this paper: http://www.phytojournal.com/archives/2018/vol7issue1/PartF/6-6-376-622.pdf Do note that the authors also make reference to a paper that studied chemical induction of chlorophyll mutations in seeds / seedlings. I also found one reference to bleaching mutations being caused by hybridizing.
Hmm... Interesting that you mention hybridization. In this particular area we sowed fernleaf dill, but we also have a lot of fennel (Florence and non-bulbing) growing around the property. I have long heard that fennel and dill will cross-pollinate, although I've been skeptical of such an inter-generic hybridization. Now, however, I begin to wonder...
My guess would be bronze fennel. They are pinkish or pale often enough when young. Yellow is a bit weird. I have seen chlorotic shoots on a number of different plants though, so I would really like to know what causes that. Have you tasted it yet? :)
