I spent years being disappointed in mid-Summer, when my petunias & vinca minor would suddenly wilt & turn brown & die. Was told, it's verticilium, or fusarium wilt, that does it. It is common in soils where cotton has been grown and in West Texas, you cannot find any land where cotton has not been grown (unless you're on a canyon wall). I was told, the way to get rid of it is to cover the flower bed with a plastic sheet & let the sun bake the wilt out of the soil. This was not an option for me, as I had bulbs & shrubs in the same soil & did not wish to cook them & their roots. So, I decided to only plant vinca minor & petunias in containers. I bought new pots, or washed out older pots with 10% bleach & let 'em dry. Then, I only used store-bought potting & top soils, as well as sand & whatever else I thought would be good for the plants. This method worked great, but then I was limited to having these fine flowers only in pots. Then, I stumbled upon a product called Monterey Aleite and it seems to work, but it recommends it be used only on established plants (or the soil in which established plants grow, that is). It is pretty much impossible to establish your plants in wilt-laden soil. So I have gone ahead & planted some in the ground & let them sit a month & then apply the Aleite stuff. I suppose you could put the stuff on soil prior to planting petunias & vinca (also snapdragons are susceptible to the wilt) and then plant them later. Otherwise, I stick to containers for these and I make sure I do not contaminate the container with my own naturally-occuring soil. I wash my hands thoroughly before handling wilt-susceptible plants and I sterilize my tools, or dedicate some tools to strictly be used in containers to avoid the wilt. Have read that verticilium wilt & fusarium wilt are not airborne, but soil-borne, however in West Texas, if it's in the soil, it gets airborne, let me tell y'all! Anybody had any success fighting this darn wilt? Edited to correct name of product: it's Monterey Aleite, not California Aleite.
I live in West Tennessee surrounded by cotton patches. I use an excellent systemic fungicide called Halt. You can use it on just about everything except fruit trees.
