58 January 20, 2007

I received an e mail this week from Tony in West Newbury. He has had a problem with moss growing in his lawn. He has thinned out the trees, limed the lawn and used moss killers to remove the moss. He doesn’t seem to have much luck at stopping the moss from growing. I figured that moss is probably a problem for many people in this area, so I’ll see if we can solve Tony’s problem and everyone else’s problem who has moss in their lawn.

Moss isn’t really a plant as we know plants. It is a pretty old critter that has been around since the dinosaurs. For moss to grow, it needs acid soil, poor drainage and shady conditions.  I know that Tony has tried all of the things he can to eliminate the moss, but I would guess that the problem is due to poor drainage. Many years ago, I lived in West Newbury. One of the things that you can count on when you live there is that you are either going to have sandy soil or clay soil. This probably has to do with where the Merrimack River flooded the town several million years ago.  Areas further away from the river have sandy soil and those closest to the river have clay soil. This has to do with how the soil particles settled after any floods. The heavier sand particles would settle first and the lighter clay particles will settle last. Those areas with clay soil will have the least amount of natural drainage.  This lack of drainage make for a great place for the moss to grow. Even letting in more sunshine and liming the lawn hasn’t helped because we have had two relatively wet springs in a row. Moss loves to grow in this weather. All in all, I think you will find that more and more people are having problems with moss due to the fact that the soil remains wet. The solution, of course, is to increase the amount of drainage. The most effective way is to take off the top 6 inches of soil and replace the soil with a good quality loam. Not an easy task, but the most effective one never the less. A cheaper but alternative method is to try to break up the clay soil. This can be done by tilling sand into the clay soil. You can also break up clay soil by applying gypsum to the soil. The gypsum breaks up the particles of clay. This allows the water to drain through the particles of clay. With repeat applications, over the years, the soil will begin to drain better. By attacking all of the conditions that moss needs to grow, you can successfully get moss under control. I am not saying that this will be easy. I am saying that it can be done.

One of the things that does add to the problem with moss is our constant supply of acid rain. The rain actually makes the soil more acidic. To overcome this, you need to apply at least 1 bag of lime per 1,000 sq. ft of lawn area. This rate just offsets the effects of acid rain. It does not help to offset the acidity that is already existing in the soil. It could be entirely possible that you may need to apply 2 or 3 bags of lime per 1,000 sq. ft. to correct the condition. This can best be determined by a Ph soil test. You can buy these test kits in most garden stores.

The ultimate control of moss is best achieved by attacking it on all fronts. As I said, this is not an easy job. However, if you want to get rid of existing moss, you have to plan your “attack” and follow through for a few years to get the moss under control.

Well. that’s all for this week. I’ll talk to you again next week.