In the 1950s, clover went from being a vital component of a healthy lawn to being a noxious and disliked weed. Clover's decline can be traced back to the commercial release of the herbicide 2,4-D in 1945.
Soon after its release, chemical companies launched an intensive advertising campaign to convince the public that a weed-free lawn was a must for any responsible homeowner – which, incidentally, is easily achieved with regular sprays of 2,4-D.
Today, lawns are the largest irrigated crop in the United States, covering three times the area of corn. Lawns use one-third of residential water consumption, an estimated 9 billion gallons of water per day. To keep them ideally weed-free, homeowners need to apply 10 times more chemicals per acre than farmers do to grow food.
It's time to consider alternatives to reduce the cost and environmental impact of lawns. One small but important alternative is reintroducing clover. Clover reduces the need for fertilizers, herbicides and irrigation water, and provides a valuable food source for native bees.
Clover is a nitrogen-fixing plant, meaning it can use atmospheric nitrogen for itself and its neighbors, and its deep roots allow it to remain green with significantly reduced irrigation.
These flowers provide high quality pollen and nectar that are essential for the survival of native honeybees. If anyone in your family has severe allergies to honeybees, it is wise not to plant clover in your yard.
Clover has some drawbacks: It's not as hardy as grass and can't stand up to foot traffic. Depending on how you care for it, it can look patchy and untidy. It goes dormant after the first frost, limiting its effectiveness as a ground cover.
The goal: hybrid lawn!
It became my gardening goal to move to a hybrid lawn that would take advantage of the benefits of grass and clover and avoid all of their limitations. How hard could that be?
Turfgrass looks best from spring through the warmer months of early summer. Clover looks best from early summer until the first frost. To achieve my goal, I need to allow the grass to grow in the spring and the clover to dominate in the summer.
Where do we start?
My first step is to replant with clover. I've started experimenting with overseeding, which doesn't require removing the existing grass. Just mow the lawn on the lowest setting on the mower, remove the weeds, sow clover seed, lightly rake, and keep moist until the seeds germinate.
I soon discovered that frost sowing was a better and easier way to sow clover. Clover germinates when the soil temperature is very cold (38°F to 42°F). Sow the seeds when there is no snow and the grass is frozen. The repeated freezing and thawing ensures that the seeds are ready to germinate when the soil warms up.
I sowed White Dutch Clover because of its drought tolerance, long life span, and short growth habit. Recently, a variety has been introduced that has a slower growth habit, fewer flowers, is more drought tolerant, and has improved tolerance to mowing. This variety is patented and is sold under several product names, including microclover and miniclover.
So, how are you?
After seeding most of the lawn, I've been experimenting with fertilizers, mower heights, mowing frequency, irrigation, and I'm looking forward to experimenting with a new variety of white clover.
My experiments have confirmed that clover is indeed a short-lived perennial that requires annual sowing to minimize spotting – fortunately, frost-induced sowing makes this an easy task.
It wasn't a surprise to me that I needed to apply nitrogen in the spring to “green up” the lawn. Where I applied about half the recommended amount, it was enough to wake up the grass, but low enough not to harm the clover. No additional applications were needed.
When clover begins to cover your lawn, raise your lawn mower to its highest setting, about 4 inches. This height will prevent damage to many of the clover flowers. Raising the mower will also allow you to mow less frequently.
The height of the mower will have a big impact on the appearance of the clover. Clover has a plant characteristic called resilience that allows it to grow to almost an acceptable height. If you mow clover to a height of 3 inches, it will stop growing at about 4 inches. The more you mow the clover, the smaller the leaf size will be, and conversely, the less you mow the larger the leaf size will be.
After more than a year of experimentation, my goal of a hybrid lawn is still not achieved. Introducing clover by overseeding has proven easy, but achieving and maintaining a lush, tidy appearance is a significant and unnecessary challenge.
Although we haven't yet achieved our goal of a lush, eco-friendly hybrid lawn, we are encouraged by the possibilities. We are beginning to see what's possible. Experimenting with hybrid lawns has proven to be more fun and rewarding than maintaining a monoculture lawn.
• If you have any gardening questions, contact the Master Gardener Clinic at 509-574-1604 or email gardener@co.yakima.wa.us.
