The Grass Doctor

Moss! Moss! Moss! Recently applied moss killer to yard. Some is black/dying...now what?

My husband and I purchased our first home last September and the previous owner must have been a fan of moss (or a lazy bum). We are currently working on the front yard and saving most of the back yard for next spring. Our problem is... the moss! The yard seems to be more moss than grass. It looks nice and green but its moss ridden! I purchased some Scotts Turf Builder W/Moss Control which kills the moss and fertilizes the grass to be hardier so moss doesnt grow back. But what I dont really understand is...What do I do after the moss has started dying? There are some areas where it hasnt, and I plan to try some liquid Moss Out that wont hurt the grass, but in many areas the moss is turning black as it is suppose to. I am trying to be patient but I am not sure what I am to do at this point. Once it turns black am I suppose to dig it out and seed? I have grass seed... Or is the moss suppose to decompose entirely and leave empty spots for me to seed? I applied the Turf Builder a good month or so ago and some of the smaller moss spots started turning blackish. We also have clay acidic soil which is why the moss is thriving so much. I can tell the yard wasnt cared for, probably for years. We live in Western Washington where we get a lot of rain. So even with just mowing and never watering, you can have a green yard. As far as our lumpy and mossy backyard goes, I think were going to get it de-sod and relayer the soil with better draining properties and add a few french drainage systems while its all torn up.

Public Comments

1. Moss killer is temporary at best. You have to alter the environment to rid your yard of it. Limb up the trees to allow more sunlight, improve the drainage of the soil, raise the ph with lime, amend the soil so that the ground favors grass growth instead of moss. As for me, I am encouraging moss to grow on the NW side of my house. I like it. Green, low maintenance, pretty, and very soothing to just relax under the trees with. I just pull the occasional weed from my moss garden, rake the leaves off of it, and let it be. Wiki has some good articles on cultivation and eradication of moss.
2. You live in Western Washington. The weather map says you get 65+ inches of rain per year. With that climate, you will always fight the moss, it will return every winter. Every time the wind blows from the direction of your Olympic and Cascade Forest, millions of moss spores are reseeding your lawn. (Moss is a primitive plant that reseeds by spores, instead of making seeds. It is the missing link of the plant world) There is no way to get rid of it unless you can dry out the weather. The guy before you probably gave up and decided to let the moss grow since it is the natural vegetation for you area. If you spray moss out on the lawn, be careful not to get over spray onto shrubs and plants you want to keep. Moss out will kill many border plants, as well as thick bladed grasses and clovers in your lawn. Once the moss has turned black, you can thatch your lawn and remove the dead moss, then over seed, or you can over seed and in a couple of months the dead moss will have broken down supplying nutrients your lawn needs. It depends on whether you want to get rid of the dead moss immediately or let it lie and look at it until it decomposes.
3. With 65+ inches of rain a year, I think you are going to be fighting a losing battle. The previous owner probably wasn't lazy, they just realized that working against nature was ineffectual at best. I have to ask, did you move there from the Midwest or out east? If so, you need to rethink the lawn thing. You are living in a temperate rain forest. Moss is a given. Lawn grasses are not. Learn what grows in your area naturally. Take some hikes into the woods and look around. There is more beauty in the natural vegetation than in water guzzling, pollution making (do you know how much pollution a lawn mower emits?) lawns. What you are trying to do with your lawn, is the exact opposite of someone trying to grow a lawn in a desert. It doesn't work.
4. So, you and I have to live with some moss, as our weather and locality is perfect for its growth. There are things that we can do to restrict its growth though, so it can become a lesser partner in our lawns and beds. You've mentioned drainage, and anything that helps drainage will decrease its hold on your garden. I also aerate my lawn, especially in spring and fall, which increases the rate at which water will filter down, as well as providing air around your grass roots. You can also infill holes with some sharp sand, to further improve top level drainage. Check that your grass varieties are ideal for your location, as the stronger the lawn, the less potential the moss has to take over. If you have some shady areas, get a species that is better for shade growing - this could either be if you totally re-do the lawn, or for sowing into bare spots. Also, feed your lawn, as this will increase its coverage and strength. In fall time, add a special fall fertilizer that encourages root growth, which really makes for a successful lawn. I remove as much moss as I am able to manually, before I apply moss killer. This isn't the norm, but I spend hours taking it out by hand each year - OK for those with smaller areas of bad moss growth. Otherwise it's better to rake over the dead moss to remove it - as the moss killers only kill what they touch, there is still usually some parts of the moss plant that remain alive, and thus repeat treatment, a few weeks later, is more effective. So, overall, improve the drainage, remove anything that's causing unnecessary shade, and grow grass species and varieties appropriate for your lawn spot. Then feed to keep your lawn as strong as possible. Aerate each year too, and consider adding some extra drainage, to help surface water drain downwards. Hope this helps. Good luck! Rob