Hello UBC : I work for the Resort Municipality of Whistler gardening crew. I have a question regarding controling weeds in the landscape. We are a pesticide free Municipality and have been so for years and we do mulch certain areas every year. Our budget doesn't allow us to mulch all of our areas where we have shrubs planted. Therefore we have to weed manually and it seems every year the weeds seem to get worse in these same areas even though we try to keep on top of them. When we weed we mainly use pitch forks and cultivators and cultivate the beds after they have been weeded. Someone on the crew had a theory that maybe we shouldn't be cultivating after the weeds have been pulled that it may in fact be bringing viable seeds that have been sitting in the soil up to the surface where they can then germinate. Has anyone done any research on this? Should we be cultivating or leaving it undisturbed ? I realize that cultivating breaks up smaller weed seeds that have already started germinating? Any suggestions would be greatly appreciated, thanks.
Personally, I'd be leaving it undisturbed. By cultivating you're not only raising possible viable seeds to the surface, you're also chopping up any little bits of root that might have been missed in the weeding process. For nasty things like Bindweed, Dandilion, Dock, and Thistles, one little root shred is all it takes for the whole thing to regenerate. I've found that foliar and soil-surface spraying with white vinegar will discourage weeds from regrowing; so long as you keep a mild distance (say 30 or 40 cm) from your shrubberies it shouldn't have any ill effect on them....
Hi Jan, I think it is true that cultivating the soil can germinate up old seeds in the soil. It depends on the situation--what weeds are growing and what is in the beds. Sometimes it is helpful and other times you get more germination. I think mulch would serve you better however. Is there no source of wood chips in your area? Or maybe the municipality could buy a chipper and process materials from municipal clean up and maybe materials from residents? It just seems like there would be free materials (or nearly free) in your area. Maybe someone else on the forums from the Whistler area has more ideas on this. Good luck,
