During the third week of March the wet and wild winter weather has only encouraged what is natural here in the Pacific Northwest – the invasion of the moss monster.
Moss does not kill your trees, shrubs or plants, nor does it kill the lawn. It is simply an opportunist, moving in where nothing else can grow. To tame the furry green monster you must remove the four welcome mats: poor drainage, acid soil, poor fertility and too much shade.
Four steps to taming the moss monster in your lawn:
1. Poor drainage encourages moss: aerate the lawn at least once a year.
The best way is with a core aerator that removes cores or plugs of soil. Pass over the lawn in one direction, then again at right angles to the first pass, then repeat. Ignore the soil plugs that look like goose droppings. They will break down and improve the soil. Soil that is really compacted or has a lot of clay will need more aerating than thin or sandy soils. Thatching is not the same as aerating. Old lawns may need thatching, but all mossy lawns need aerating. Working a core aerator is hard on the back; this is a job I like to leave to the professionals.
2. Acid soil encourages moss: add the great bargain of Super Sweet granulated lime.
Lily Miller is a local company that makes a granulated, fast-acting Super Sweet lime. It is dirt cheap and most effective if you apply right after aerating. I like the granulated form because I can apply it with a drop spreader and there is less lime dust that could drift onto my acid-loving rhodies and azaleas. Once I started apply this stuff every year the buttercups in my moist, shaded lawn disappeared. Buttercups are like moss – they thrive in acid soil and hate lime.
3. Poor fertility encourages moss: Fertilize the lawn at least twice a year.
Fall is the most important time to feed the lawn but a spring feeding is necessary if you have moss. Lawn Rangers (riding the range in a quest for the perfect lawn) may want to fertilize three or even four times a year to encourage thick growth that leaves no room for moss. I use a slow-release lawn food so excess nitrogen won’t be washed into the ground water.
4. Too much shade encourages moss: limb up your trees or go with a groundcover.
Grass needs sun. Choosing a grass seed made for the shade will help, but for those really shaded areas the best option is to throw in the trowel on growing grass and plant an evergreen groundcover instead. This is an especially attractive option if, like me, you deal with moles, voles and field mice making highways and freeways just under the surface of your lawn. I covered up the bumpy, mossy, ugly lawn in my shaded areas with sheets of newspaper, then added six inches of topsoil and planted the area in lamium “beacon silver.” Now I don’t have to mow and the evergreen lamium hides the bumps and valleys of the underground city. Pachysandra, vinca minor and ajuga are other shade-tolerant ground covers.
If you can’t beat ‘em, go in peace with your inner zen.
Encourage the moss, discourage the grass and enjoy a no-mow, moss lawn. Add a few boulders and low-growing shrubs like Nandina and mugho pine for the look of a Japanese garden. After all, moss is beautiful, green and low maintenance so stop fighting Mother Nature and embrace the fuzzy green fur of the moss monster.