Pests affecting dill
I have dill growing, about 4ft tall and I am having trouble with seed heads being nipped. Whatever is doing this acts at night and chews a girdle about 9/10ths the way round the stem leaving the seed head nodding. It never eats the leaves or the seed head. I’ve looked for cutworms in the soil not finding any. We have gone out at night trying to see if this critter is active but so far have not seen activity. I have treated with diatomaceous earth and Bt and neither has been effective. The vegetable plot is protected by and electric fence so I doubt any 4 footed creatures are to blame. Any ideas for me?
I couldn’t find any specific mention of this problem. It sounds like an insect is eating the plant.
It could be something like a carrot weevil laying an egg inside the stem. Dill is in the carrot family and so this could happen, though only parsley, celery and carrot are mentioned in the reference- https://www.canr.msu.edu/ipm/uploads/files/TrainingManuals_Vegetable/Vegetable_Chapter5.pdf
Only certain stains of Bt control carrot weevil- http://www.entomology.wisc.edu/mbcn/veg606.html
Here are insects known to be found on dill-
You could try wrapping the plants in fine mesh, such as nylon tulle( found at fabric stores and used to make bridal veils), or light weight floating row covers, being sure it is snug around the base of the plant, and supported by tall stakes. This may keep whatever insect is coming to the plant away. However, if the insect involved is hatching out on the plant, then the netting won’t help.
If flowers continue to be damaged, take some photos, and cut some samples- cutting well below the damaged area, and send samples to the pest lab for ID.
Instructions and fee schedule are here- https://pestid.msu.edu
I hope you will get some flowers from your dill. Thanks for using our service.