I have 3 yr old aspargus and with their large root system, I am wondering how close can I run a tiller next to them. Do their roots go down or do they stay on the surface.
Becker County Minnesota
Thank you for the question. Asparagus roots do go down deep but they also spread out horizontally. We couldn't find research based information listing exactly how close you can get with a tiller to the plants but it seems to make good sense to stay at least a foot away from the bed on both sides. Layering a few inches of mulch over plants should control the majority of weeds right in the bed. Of course, hand weeding is also a must from time to time. Read more about growing asparagus in these 2 University of Minnesota Extension publications: