Moss in flower garden

Asked June 16, 2015, 12:13 PM EDT

I have a garden with both annual and perennial plants at my cottage near Lake City, Michigan. Moss is present throughout the area. Had soil tested by MSU #C4E9L8. Also, the plants such as myrtle, while looking healthy, are not growing and spreading. The area has large oak trees and maples that provide semi shade. Soil drains well. Other than shade, moisture, or acidity of soil, are there other causes? Note moss is widespread on ours and other nearby property. Is moss a significant factor in plant growth? Would putting lime on the area improve plant growth? Attached is a picture of what it looks like.

Missaukee County Michigan

3 Responses

Moss happens for these reasons or a combination of these reasons:
1. Shade... other plants are not growing and there is bare soil.
2. Compacted soil...plants do not grow because it is too difficult to get roots through the soil.
3. Wet soil... the soil is poorly drained and plants do not grow well.
4. Soil that is either too acidic or too alkaline... plants do not grow because they cannot access the nutrients in the soil.

Moss is an opportunist and a "mechanic." When other plants cannot grow, Mother Nature sends the mechanic to cover the soil to prevent erosion.

Generally, this pretty poor soil and the pH is about as low as flowers can handle. But no lime is needed. The soil has very little organic matter content at 2.4%. You would like to have 5% or greater.

The soil needs nitrogen and potassium but no phosphorus. That's part of your test. Your recommendation says:

Nitrogen: 0.1 lb per 100 sq. ft
Phosphorus: 0 lb.
Potassium: 0.5 lb. per 100 sq.ft.
This is if you were adding nutrients that were 100% pure. Nutrients are always in percentages like 0-0-60 which is sixty percent potassium.

The lack of nitrogen and potassium is also affecting the growth of the plants. Follow your recommendations and lightly scattered the recommended fertilizers around the plants. Rake in and add two inches of compost or composted manure over the fertilizer. A better solution would be to remove the existing plants and park them in the shade and put down four inches of compost and your fertilizer, water the soil so it is damp and replant the displaced plants. At the time you are adding the compost and fertilizer, put in 1/2 lb. of lime per 100 sq. ft. of area. In the long run, removing plants and mixing in nutrient, lime and organic matter would work better than trying to work around existing plants.
Next spring, apply around the plants. This recommendation is good for three years but if the first year, the stuff was mixed in, you will see results faster.

Moss is not a detriment to plant growth. It's just telling you that even weeds can't handle the situation.

Once plants have been fertilized by either method, mulch around the plants with straw or wood chips or something else organic. Then, there is no bare soil for moss to grow on. Make sure any plants added to the garden are shade plants.

Thank you for the very detailed and thorough response. You gave me info and tips that would not otherwise know. While I did not think the soil is greatest did now have any idea it was so void of organic matter. Looks darker and not as bad as the light sand soil in area.
Regarding suggestion to take up plants and put down fertilizer and organic matter and then replace the plants. Have concern that at this time of year normally would be hot and dry so not good to transplant. This is at cottage and we are not there to water. So decided to wait till spring and follow your suggestions.

Or wait until the end of August or the beginning of September and there is plenty of time to develop some new roots. Perennials will be fine unless there is one or two with extremely long tap roots. They always sulk and so they would be better in the spring. Good luck!