I’ve read that a good way to make the phosphorus part of fertilizer available for your lawn is by using mycorrhizal fungi. I don’t want to use phosphate fertilizer anymore because our stormwater retention pond down the end of the street is getting algae blooms and it seems likely it’s at least partly due to phosphorus fertilizer.
What do you think about this? Do you know where I can get these fungi and how I should apply them?
This is a very good question Leslie.
Mycorrhizal fungi form a symbiotic (mutually beneficial) relationship with certain plant roots. They will help plants absorb phosphorus as well as potassium, calcium, copper, and iron more efficiently.
Yes, you can buy them – however – these microorganisms are naturally occurring and will already exist in your lawn. A new lawn planted on poor soil in an urban setting might benefit from an application of mycorrhizal fungi.
Instead of adding mycorrhizal fungi, improve soil conditions – and microbial populations – by compost topdressing, core aerating and recycling grass clippings as well as avoiding the use of fungicides and limiting herbicide use.
Established lawns rarely need additional inputs of phosphorus – it’s usually there in sufficient amounts. You are protecting our waters by avoiding the use of phosphorus fertilizers on your lawn.
Clean up yard waste! Grass clippings or leaves left on driveways, sidewalks or on the road will eventually wash into stormwater drainage systems ending up in our lakes and rivers. Organic yard waste is a big source of phosphorus pollution – an even bigger source of nutrient pollution than lawn fertilizers.