How do I control weeds in an unplanted garden space?
I have been planting a 50-by-100-foot garden in Coon Rapids, Minnesota, for the past 20 years, and I'm planning not to plant it this season. What is the best treatment for the space to prevent it from being overrun with weeds? Should I use Preen or cover it with newspaper and/or straw? Are there things I can do to improve the soil for planting next year?
Anoka County Minnesota
Bravo to you in thinking ahead about weed control! You are correct in thinking that your garden, while laying fallow, will grow a bumper crop of weeds. Although chemical products, newspaper, and straw can help control weeds, these materials aren't very nice to look at. Newspaper and straw will break down and add compost to the soil, but so would a green manure cover crop. According to Jill McKenzie, Former Extension Specialist at the University of Minnesota, cover crops are plants sown thickly to form a living mulch in gardens. They help reduce soil splash and erosion and keep weeds in check. When cover crops are turned into the soil to provide organic matter and nutrients, they're called "green manures." Green manures include legumes such as vetch, clover, beans, and peas; grasses such as annual ryegrass, oats, rapeseed, winter wheat, and winter rye; and buckwheat. These green manure cover crops can be planted this spring and then tilled under next spring. You can find more information in the article Green Manure Cover Crops in Minnesota. Not only is a cover crop nice to look at, it also benefits bees and other insects. Another source of information on cover crops is the Midwest Cover Crops Counsel website. Using the website's Cover Crop Selector tool, an option on the left side of the site's home page, you can enter your location information, soil drainage information, information about whether your site floods, and attributes you seek from the cover crop (weed control, erosion prevention, etc.). After you enter the information, a table showing plant options that most closely fit your needs and goals displays. Select your cover crop choice, and click "submit." A report is generated that describes the pros and cons of the selected cover crop as well as information about seeding rates, depth of seeding, and much more.