Debbie Arrington

February 1, 2014

Make ‘lawn lasagna’ to kill turf with less work

Bermuda grass still an issue when it comes to removing lawn in favor of low-water alternatives.


Debbie Arrington digs into gardening news

When it comes to lawn, our emotions run high. Love it or hate it, we usually still keep it – because taking out the turf is too much work.

As we endure the driest winter in Sacramento history, thoughts of turf removal or reduction have many homeowners re-examining their personal love affairs with lawn. Is that grass worth all that water?

But it’s not just the potentially back-breaking work of digging up turf that makes us hesitate to grab the shovel. We’re scared of Bermuda grass.

“Lets get real,” wrote reader Polly Harris. “The one reason many of us here in the Valley don’t switch to a low-water landscape is the work and toil and frustration of getting rid of Bermuda grass. Unless you have a secret cache of napalm available to you, you will never kill the darned stuff.

“Any turf area where you replant will soon be overrun by Bermuda. Bermuda roots can lay dormant in soil for an eternity. You can excavate several feet down but you will never get it all.

“We plan on not watering portions of our lawn this summer,” Harris added, “but I have neither the time nor the energy to excavate vast portions of my front and back lawns to rid them of Bermuda.”

Bermuda grass is so popular in California because it is so hard to kill. It may turn brown without water, but it will survive a drought.

But for those folks who do want to take out the lawn (or parts of it), now is the time to make “lawn lasagna.” Also called sheet mulching, this method will kill most turf grass with comparatively little effort – and no digging. Here’s how:

First, turn off the sprinklers. Mow the grass as short as possible. Then, cover the turf you want to remove with sheets of cardboard. Use a double thickness, overlapping the edges about 6 inches. Strip the cardboard of any tape or staples before putting in place.

Instead of cardboard, you may substitute newsprint (another use for your Bee once you’ve read it); use a layer at least six pages thick. (The Bee uses only nontoxic inks, but avoid the advertising circulars inserted into the newspaper; their inks may contain metals.) Pages from old phone books also work but take a lot longer to tile into place.

Cover the cardboard/newsprint layer with a heavy layer of organic mulch, 4 to 6 inches thick. Wood chips or bark work wonderfully and look good during this process, but you may also use dried leaves, straw, compost or aged manure. Then, water. Give the mulch a good soaking. That helps kick the composting process into gear.

Gradually, the mulch layers will break down into the soil. With no light, the lawn will wither and die. The worms and micro-organisms will finish the job.

When it’s time to replant the new garden in the lawn’s place, punch holes through all the layers into the ground. Don’t pull up the cardboard or dig up the lawn; it all composts in place. By summer, the lawn is gone.

As for Bermuda grass, it may survive “lawn lasagna,” but the sheet mulching process greatly weakens its resilience. Pull out the occasional runner as it rears its ugly head through the cardboard.

Solarization – which involves stretching sheets of plastic over the turf and “cooking” the Bermuda grass with solar heat – is more effective. But you’ll need to wait until summer for solarization to work best; it needs intense sun and high temperatures to kill Bermuda’s deep roots.

If it doesn’t rain by that time, we may all be tearing out lawns.

Getting the blues

Several readers wanted to know more about growing blueberries (a la Farmer Fred Hoffman) instead of lawn. Hoffman took out turf and replaced it with edible landscaping, including several wine half-barrels packed with blueberries.

Hoffman chose to grow his berries in barrels instead of directly in the ground because blueberries need very acid soil (like azaleas) and good drainage. They also appreciate consistent soil moisture. By using large containers, he could manage all those requirements for the blueberries.

Southern highbush blueberries (rather than northern highbush) are the varieties that grow best in Northern California. They need fewer “chill hours” (time below 32 degrees) to set berries and can withstand our summer heat. Most are self-pollinating but do best if planted with other blueberry bushes in different varieties.

From his own experiments, Farmer Fred recommends the following varieties: Sharp Blue, Jubilee, South Moon, Blue Ray, Sunshine Blue and Misty. A UC master gardener trial in Santa Clara rated these varieties as best tasting and producing for NorCal gardeners: Reveille, Misty, Sunshine Blue, Bluecrop, Georgia Gem and O’Neal.

Looking at those two lists, I chose to grow Misty and Sunshine Blue. Misty tends to get leggy with a few 5-foot branches, but Sunshine Blue stays very compact (less than 3 feet tall) and bushy.

In addition to pink flowers and blue fruit, both offer brilliant fall foliage with bright red leaves. Besides the fruit, they look prettier than a Bermuda lawn, too – even in barrels.

Related content




Entertainment Videos