Rye Not?

I employed a new weapon in my perennial war with the weeds this year: winter rye. 

In years past, at the close of growing season, I cleared my garden of spent tomato plants and weeds, put my tomato cages in storage and left the plot at the Chinquapin Organic Gardens fallow for the winter. Every spring, I found it in exactly the same state, swallowed by a sea of thick weeds, some as tall as four feet. 

"Whoa!" my kids said every spring on our first trip back to the gardens. 

I'm told the winter rye will eliminate the weeds and, more importantly, the need to spend two to three full days of backbreaking work clearing the plot. Winter rye—known as a type of "green manure"—also should improve the soil in a host of ways, said Amber Kim Dewey, an Illinois master gardener who has been gardening with her family at Chinquapin for six years. 

I met Dewey at the gardens recently to learn about winter rye and get a look at a demonstration plot she covered with the seeds a few days earlier. "Suppressing weeds is really important," Dewey told me. "This place is a little overgrown; you get lots of weeds from your neighbors."

Winter rye grows quickly and survives the winter in our area. Its thick, aggressive root system crowds out other weeds, and because the roots are allelopathic, it produces a chemical that prevents other seeds—weed and vegetable seeds—from germinating. 

If left to grow to maturity, winter rye can be used as a cover crop which means it can be harvested and used for straw to mulch around transplants or along garden paths. 

What I plan to do, though, is till the rye under in mid-March when it's about 8 inches tall. It's called green manure because it adds organic content when it's incorporated into the soil. It also improves the soil structure, creates airspaces for improved root growth and adds nutrients, among other things.

Dewey cautioned me to wait a full two to three weeks after tilling the plot before I sow the garden with seeds. The allelopathic chemicals in the winter rye take that long to diminish, she said. Likewise, if you use the straw harvested from the winter rye in your garden, it can only be used as mulch around transplants or in pathways as the straw continues to release the chemicals. 

So, how do you go about planting winter rye? First, clear your garden of weeds and debris, then loosen the soil with a hoe. It's best to broadcast the seed immediately after preparing the soil, Dewey said. I spread a two-pound bag of seed on my plot (which measures 18 feet by 20 feet), raked the seeds in, then watered. Dewey suggested I water at least every other day until the rye is established. 

The day I met Dewey at the demonstration plot, there were no signs of growth in the garden. A week later, it was covered with a surprising carpet of green rye a few inches tall. It typically takes about 10 days for germination, depending on the temperature, she said. The best time to plant rye is from October to mid-November. 

I have high hopes that come spring, I won't find a garden plot filled with chest-high weeds.