As we celebrate the Ides of March, the madness of March, Einstein and my brother’s birthdays (happy birthday, bro!), this main street gardener wanted to answer a couple of questions asked this week regarding the use of fall cover crops on Wellfield’s quilt garden.
Cover crops are a temporary planting of a single or mix of species to inexpensively build soil. They are utilized largely in agricultural production systems, but when carefully applied, can have home landscape utility as well. Cover crops, or green manures, are grasses, grains or members of the pea/bean family typically though not exclusively. Green manures can relieve compaction, add additional organic matter and nutrients, work as a mulch layer with all the benefits of mulch and, most importantly for the soil conserving farmer, hold soil in place against fall and spring erosion.
Homeowners can use cover crops in ornamental and food focused horticulture with some forethought, as the provided links well describe. We utilized cover crops in the Quilt Garden for many of the reasons listed above. It is a great space to demonstrate and introduce people to yet another soil building tool. The crop fills the space with something green in a space left bare for about half of the year.
The mix used includes peas, clover and ryegrass which dies back with winter’s chill, creating an organic mulch layer. The hairy vetch and winter rye survive our cold months to green up and provide some nutrients in the spring.
We take several steps to transition the bed space from cover crop to a display of summer bedding annuals. First, we cover the crop with black plastic for approximately a month to cook the crop. Thirty days or so later, the plastic is removed and any greenery left at the edges is dispatched. Normally, it is recommended to till the cover crop into the soil, however we are taking a different approach. Instead of taking the extra back-breaking step of tilling, we will simply “till” the cover crop in as we plant. Planting a quilt garden requires closer than normal plant spacing, thus a lot of soil is going to be dug and turned with the trowel.
This is our third winter cover cropping, so we are still learning as we go, but turning a hard packed, sandy hill into a beautiful space for others enjoyment is worth it. Look for Wellfield’s “Peace Crane” quilt garden to be planted sometime near Memorial Day, and enjoy it all summer long when you visit the Gardens!
Josh Steffen, Horticulture and Facilities Manager