Q: Scattered white mushrooms have appeared in our lawn recently. They seem to be in areas of both sparse grass and lush grass. How can I control them?
In short, you can’t get rid of them (fungicide won’t be effective) and likely don’t need to. The mushrooms are probably one of the many kinds of harmless fungi that live in organic matter within or underneath the lawn. There are three basic categories for mushroom-producing fungi that appear in a lawn, all of which are beneficial: wood decay, mycorrhizal and saprobic.
Wood decay fungi break down old, buried wood in hidden stumps or root fragments left after a tree has been removed. Their mushrooms can continue to appear months or years after the tree was cut down, as long as that food source remains. Since they consume those obstacles to root growth and drainage, and release nutrients into the soil that turf roots can use, they are helpful recyclers.
Mycorrhizal fungi grow alongside or within plant roots, forming a partnership that benefits both organisms. The majority of land plants rely on mycorrhizal relationships to stay healthy and be more resilient to stress.
Saprobic fungi break down organic matter, such as withered grass blades or dead roots. As with wood decay fungi, they recycle nutrients back into the soil as a natural fertilizer.
No management is needed for any of these fungi, since they do not infect the turf or cause disease. The common fungal diseases of lawns – brown patch, rust, red thread, leaf spots, etc. – do not produce visible mushrooms. Mushrooms may appear in areas of sparse or dead turf, especially after rain or irrigation, but rarely are they the cause of browning or dieback.
Fairy rings are the only mushroom-producing fungi that may appear in a lawn as the cause of lawn decline. Named for their seemingly sudden and coordinated appearance of rings or arcs of mushrooms, some types of fairy ring fungi can interfere with the soil’s absorption of water. In dry conditions, turf in the affected zone can desiccate and turn brown.
You can remove the mushrooms manually if you’re concerned a pet or person will try to eat them. (Never assume lawn mushrooms are edible.) Remember, mushrooms for a fungus are a bit like the flowers or fruit of the plant world: they are reproductive structures, and the “body” of the fungus remains inside whatever it’s growing in. Just like picking a flower or harvesting apples won’t eradicate the plant, removing mushrooms won’t eliminate the fungus.
Q: Are there vegetables that can be planted this late in the season?
Yes, some leafy greens will sprout now, pause growth during winter, and resume maturing in spring. Time is running out, though: lettuce, spinach, arugula, and kale can be direct-sown into the ground through mid-October. Cover these late plantings with a cold frame, temporary greenhouse, or row cover fabric to give them some insulation from chilly nights.
Aside from low temperatures, the other main factor halting growth is insufficient sunlight. As the days shorten, we’ll soon reach a point where there is too little daylight (less than 10 hours by mid-Nov.) to support enough photosynthesis for growth.
Be sure to fertilize the seedbed upon sowing to give the seedlings a boost, keep the soil moist if the weather skews dry, and protect seedlings from pests. The young plants will go dormant and re-grow in the spring when temperatures become mild again and there is enough daylight for photosynthesis.
University of Maryland Extension’s Home and Garden Information Center offers free gardening and pest information at extension.umd.edu/hgic. Click “Ask Extension” to send questions and photos.
