Excessive Yard Moss and Fungi

Causes on the Ground

• Most fungi are helpful microorganisms, because they slowly consume organic material within the soil to make the nutrients available for root uptake. Even moss is a nonparasitic plant, although it can eventually choke out other plants if the area remains wet and shady, along with limited air flow. Lawns are particularly vulnerable to space competition if moss proliferates across the soil -- the desired grass suffocates at both the root and foliage levels as thick moss moves in. Compacted soils create perfect habitats for excessive moss and fungi growth, because water cannot percolate down into the ground, and puddles remain stagnant on the surface.

Tree and Shrub Causes

• If you have a particularly wet winter, your trees and shrubs may accumulate some moss populations on their limbs or trunks. Although moss should naturally die back as drier weather sets in, trees and shrubs with heavy foliage and poor air circulation actually encourage more moss growth. Struggling plants, such as trees that are nutrient-deficient, do not have the vigorous growth necessary to disturb moss populations on the trunk or limbs. As a result, slow-growing plants become covered with moss, especially if moist and shady conditions prevail.

Sunlight and Moisture

• The simplest strategy to fight excessive moss and fungi is increasing air flow around the plants and altering the irrigation patterns. Do not set an irrigation timer and ignore it during your rainy season. Widen the watering session periods, or manually activate the system when the yard truly needs water. Prune your surrounding shrubs and trees to allow a natural breeze through the branches. Proper irrigation and good air flow help the yard use natural evaporation to reduce wet areas for less fungi and moss growth.

Preventive Yard Maintenance

• Reduce puddles across your yard by incorporating organic matter into the soil. For turf grasses, aerate the area using a hollow tine machine, with which you pull soil cores from the ground to improve drainage and texture. If you have a thick thatch layer of decaying stems and foliage, dethatch your lawn to increase water penetration into the ground below. If you have any old tree stumps nearby, fight fungi populations by removing these food sources. Although you need beneficial fungi in your soil, harmful fungi can easily infiltrate a stressed yard; apply fungicides as necessary, based on the fungal type.