Moss in Garden Beds


My sunny garden beds have Moss growing in them. Is this bad? Should I get rid of it for reasons other that “looks” and can I compost it? Many thanks.


Thank you for contacting the Toronto Master Gardeners.

The appearance of moss in your garden bed can be an indication of several conditions:

Soil acididty: moss prefers to grow at a pH of 5.0-5.5. When the soil pH drops below about 6, certain nutrients in the soil are no longer available; creating conditions of low fertility that allows moss to invade. Areas that receive heavy rainfall or watering tend to develop acidic conditions favourable to moss growth.

Low Feritity: Soil that is nutrient poor and/or unfertilized encourages moss growth.

Soil compaction: Moss can easily grow in compacted areas where other plants will not survive.

Shade: Moss requires shade to grow. Even a garden bed which receives full sun if densely planted can provide enough shade for moss to grow.

Moisture: Moss loves poor drainage, overwatering all contribute to creating a moisture-rich environment.

The above list might seem daunting however once you have isolated the problem it is relatively easy to fix.

The first step would be to clear the bed of moss. Manual removal is the easiest method. Simple hoe or rake off the upper layer of the bed containing the moss. Light raking will also aerate the upper layer of the soil  and reduce compaction. Aerating compacted soil regularly will discourage moss growth. If you decide to compost the moss be aware that moss decomposes relatievely slowly.

I suggest that you test your soil for pH to see if it has become more acidic over the years. Amending your garden bed yearly with well rotted, organic compost will not only improve your soil structure it will also improve soil fertility, add much needed nutrients to your garden bed and improve the acidity of your soil if that is a factor.

Improving soil drainage  and thinning out overhanging or adjacent shrubs, trees and densely planted beds to increase light penetration and air circulation can prevent moss from reappearing.

The following link provides additional information on mosses and how to treat the problem :