Believe it or not, fungus can be good for your plants! Millions of years ago, plants established a symbiotic relationship with soil organisms called mycorrhizal fungi. The fungi serve as a secondary root system, extending themselves far out into the soil to extract water and mineral elements for their host plants. In return, the plant supplies the fungi sugars on which to live.
Plants with thriving mycorrhizal root systems are better able to survive and grow in stressful environments because the mycorrhizae are able to absorb, accumulate and transfer water and mineral elements to plants more effectively than roots without mycorrhizae.
In forest soils, mycorrhizal fungi are abundant. However, most of today's landscape environments have been created as part of construction projects that disturb or remove the topsoil where plant roots and these beneficial fungi live. As a result, the ground has no natural topsoil and is virtually devoid of mycorrhizal fungi, making it much harder for these plants to thrive.
Luckily, there are now several products available to gardeners and lanscapers so that they can bring healthy organisms back to the soil. Look for products that either have mycorrhizae as the main ingredient or as part of a fertilizer. Many horticultural experts recommend using products with mycorrhizae when you transplant existing plants or adding them to garden beds or container plantings.