Hi Weeds take over our garden every year. We live on an old farm garden is next to a field. We have used screen and cardboard(works best) to block weeds. We pull endless quackgrass, etc. out in spring and all summer but it eventually takes over. My husband rototills every spring, not sure if we should be doing this. We bury all of our kitchen compost.We only use organics. Any suggestions would be appreciated.
Oakland County Michigan
Weed management in organic gardens is always a labor Intensive process. There are a few techniques you can use.
For quackgrass, a perennial grass, rototilling is just producing more plants from each cut piece. It is difficult to control without the use of chemicals. Here is an excerpt from MSUturfweeds.net for quackgrass-
“Due to the perennial nature of quackgrass and its well-developed rhizome system it is very difficult to remove by mechanical means. Methods include digging up the offending patches, including several inches of soil and replacing with new topsoil and reseeding. ( when dealing with turf grass areas) However, the rhizomes of quackgrass can grow 6-8 feet deep in the ground and these rhizomes could potentially "push" new plants to the surface. Another option is solarization. This method uses clear plastic fastened securely to the ground over the quackgrass areas. Be sure to cut the plastic slightly larger than the patches. Leave the plastic in place for 5-7 days in the spring or summer when the weather is nice. The plastic will help trap the heat close to the soil surface and hopefully devitalize the plant material. After removing the plastic you may reseed the area(s).”
The complete entry is here-http://www.msuturfweeds.net/details/_/quackgrass_45/
Your use of cardboard is one of the recommended non-chemical ways to smother weeds. Any thick mulch maintained over the paths and around plants will help. For annual weeds like crabgrass an organic pre-emergent option is corn gluten meal, which has some seedling suppression action.
Here are some articles on weed control in the garden( some of these have chemical control included)
Not our climate but some ideas here- https://www.ctahr.hawaii.edu/UHMG/downloads/Organic_weed_HG.pdf
Using no-till methods may be an advantage for you-
I hope some of these ideas will help you. Thank you for using our service.