Moss Control for Lawns
The best way to effectively
and permanently control moss in the lawn and garden is to correct
the conditions that are favoring moss growth. Moss grows
better than most types of grass in areas with heavy shade, poor
drainage, and compact soils (Douglas, 2000).
- Mosses are often found in cool,
shaded areas of the lawn where they are more competitive than
grasses. The following physical control methods can help prevent
and control moss growth in shady areas.
- Trim shrub and tree limbs that
create shady areas on the lawn.
- Complete removal of shrubs or trees
may be needed in areas that receive less than 3-4 hours of direct
sunlight or 6-8 hours of filtered sunlight. This is the amount
of sunlight that is required for most grasses to grow well (Douglas, 2000).
- Mow at the top of the recommended
mowing height for each grass species. In general, no more than
1/3 of the top growth should be removed when mowing. This will
encourage deep rooting and maximum leaf surface area, which will
allow the grass to absorb more sunlight (Scott
and McCarty, 2000).
- A shade-tolerant grass, such as
St. Augustine grass or fescue, can be planted in partially shaded
areas (Everest, 2000).
- Instead of grass, shade tolerant
ground covers can be planted in shady areas in the lawn. Two examples
include pachysandra and myrtle (Vinca minor)
(Douglas, 2000; Scott and McCarty, 2000).
Do not use invasive species, such as English ivy.
Excessively wet soils can promote moss growth because mosses grow
better than grass in wet, poorly drained soils. Some physical
control methods that target excessive moisture include:
- Watering the lawn only when it
is needed. Regularly scheduled watering and automatic watering
systems will often over-water the lawn, especially in shaded
areas (Scott and McCarty, 2000).
- Adding sand or soil to localized
low-lying areas. This will increase the elevation. This will
allow more sunlight and wind to dry the area out (Everest,
- Contouring or trenching wet area,
which will allow excess water to be drained.
- Installing french drains or subsurface
drainage tiles in large areas of water build-up (Scott
and McCarty, 2000).
- Removing thatch (dead organic matter)
from the lawn, which will increase grass vigor and decrease water
retention on the surface. Thatch can be removed by hand raking
or with a vertical mower (Newfoundland & Labrador Agriculture,
- Moss growth in the lawn and garden
can also be encouraged by heavy or compacted soils. Compacted
soils have a decreased amount of air, water and nutrient movement,
thus causing stress to the grass and allowing mosses to move
in. Furthermore, the decrease in water movement can prevent water
drainage in the compacted soils, thus favoring moss growth. Controlling
mosses by increasing the aeration of the soil can be done in
- Core aeration or aerification is
a process that removes cores of soil from the lawn. It can be
done with a manual sod-coring tool or a power-driven core aerator
and should be done every year (Scott and
- Incorporating several inches of
organic matter into the compacted soil will improve the texture
and draining in the soil (Douglas, 2000).
Physically controlling mosses is
often used along with chemical control to increase the chance
of completely eliminating mosses from the lawn and garden. Physical
control methods can also be used as an effective, chemical-free
alternative to chemical control. Most physical control methods
are inexpensive and take only a short amount of time to implement.
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