I try to do gardening without the use of chemicals. I have recently started to grow glads here in CO (it is dry here). Does anyone have knowledge or experience growing glads w/o chemicals or have any sources? Right now the grasshoppers are eating them a lot and soon I will have to store the corms and treat for thrips. :(
Diatomaceous Earth is but a topical agent.
I am pessimistic. You would at least have to peel the corm until it is totally "naked", and then, there is still an indentation at the place that new growth emerges from. Perhaps, an appropriate NEEM oil formula would be a better choice but this is just a suggestion, I have no own experience.
dadofnine... wish I had advice for you. I am new to gladiolas. I planted about 20 corms late February, directly in the ground. I have approx. 2 feet of healthy growth on all of them. I have used no chemicals whatsoever, and the soil in my area is that nasty hard clay. I mixed in some organic potting mix and that's it. So far, fingers crossed no problems whatsoever.
Best of luck with your glads. :)