Q&A: Ridding a lawn of moss, pruning a newly planted tree
Garden writer Ciscoe Morris answers readers’ questions about getting rid of moss on a lawn and how to prune newly planted trees.
Special to The Seattle Times
Northwest Horticultural Society Presents ‘The Legacy of Elisabeth Miller and Her Garden’: 7:15 p.m. Wednesday (Nov. 13). Presented by Richie Steffen. Center for Urban Horitculture, 3501 N.E. 41st St., Seattle; $5 members/$10 nonmembers (www.northwesthort.org).
Northwest Perennial Alliance Presents ‘Garden Pests: How to Detect and Identify Troublesome Insects in Your Pacific Northwest Garden, and What to do When You Have Them’: 1 p.m. Sunday Nov. 17. Presented by Sharon J. Collman. Doors open at noon for plant and seed sales. Center for Urban Horitculture, 3501 N.E. 41st St., Seattle; free for members/$10 nonmembers (www.northwestperennialalliance.org).
SantaPaws at Molbak’s: 2-5 p.m. Sunday Nov. 17. Molbak’s, 13625 N.E. 175th St., Woodinville; $20 donation benefiting the Seattle Humane Society for a professional, mini photo session with dogs and Santa, and a digital file of the best shot (www.molbaks.com).
In the Garden
Q: If I apply lime to my lawn, will it rid it of moss?
A: Lime doesn’t kill or even harm existing moss. The only effective way to rid your lawn of moss is to rent a power-dethatching machine to remove the moss, then apply a moss-control product. Follow the directions carefully because some moss-control products can be harmful to pets and children. Once the moss has been dealt with, however, applying lime can play a key role in keeping it from coming back. That’s because moss is opportunistic and can’t stand competition. It can only thrive in thinned out grass and can’t compete in a thick, healthy lawn. Hence the best defense against moss is to keep your grass growing vigorously. Lime helps promote strong growth by providing calcium, a nutrient normally deficient in Western Washington soils but necessary for healthy grass growth. The only way to know exactly how much lime you need to apply is to have a soil test done, but you’ll rarely go wrong if you apply 30 pounds of agricultural lime every five years. Be aware that grass won’t grow well in shade, and even adding lime will do little to make grass grow thickly where it doesn’t receive much sunshine. Also don’t forget to allow two weeks before or after fertilizing before liming your lawn. If lime is applied when lawn fertilizer is present, it turns the nitrogen in the fertilizer into a gas. The gas is harmless to humans, and won’t make you laugh or talk funny, but it will render the fertilizer ineffective.
Q: I recently purchased a couple of trees for my parking strip. Should I prune the trees after planting so that they have a nice shape?
A: It’s probably a good idea to do a little formative pruning when you plant a new tree, but don’t overdo it. Don’t make the mistake of cutting back all of the side branches on the tree to give it a round canopy. Heading cuts of this kind encourage major sprout growth, and you’ll spend an incredible amount of time removing unsightly twigs that will grow nonstop from the end of the branches for years to come. The goal when pruning a newly planted tree is to establish a sturdy, attractive branching structure and fix any minor problems that could cause trouble down the road. The first task is to remove the three D’s: dead, diseased or damaged branches. Next remove any branches that are growing into the center of the tree, or any smaller branch that is crossing over a bigger one to keep possible rubbing from creating wounds in the bark. Most importantly, check for co-dominant leaders. This is where two similarly sized branches are growing vertically, straight up from the same joint in the tree. Choose the strongest one and remove the weaker branch by cutting it back to its point of attachment in the tree. If left in place, co-dominant branches develop weak attachment and at some time in the future, one or both of the limbs are susceptible to breaking off in ice or wind storms, ruining the health and appearance of the tree. The last and most important step when pruning a newly planted tree is to obey the law of haircuts and eating hot-fudge sundaes: Know when to stop!
Ciscoe Morris: firstname.lastname@example.org “Gardening With Ciscoe” airs at 10 a.m. Saturdays on KING-TV.
About Ciscoe Morris
Ciscoe Morris' column runs Thursdays. His show "Gardening with Ciscoe" airs at 10 a.m. on Saturdays on King 5.