If this is your first visit, be sure to
check out the FAQ by clicking the
link above. You may have to register
before you can post: click the register link above to proceed. To start viewing messages,
select the forum that you want to visit from the selection below.
I really don't know, but there could be something left behind in the soil from something that is no longer there. Years ago, I had our sidewalk busted up, and removed when we changed it's route, and for a while after that you could see a "ghost" of where the old sidewalk ran because the grass was a slightly different color there.
Maybe a piece of equipment at the site sprung a hydraulic leak and that has contaminated the soil. Dig up some of the soil and put it in a jar of water then shake it up and leave over night to see if oil separates from the soil.
I can't believe that it has been around for 3 years but who knows. Hydraulic fluid is thick.
Fairy rings are circles or arcs of dark green grass surrounding areas of light colored or dead grass. During
spring and fall, mushrooms develop in a circle outlining the ring. These mushrooms are signs of the fungus
causing the problem. Unless the fungus is controlled, the ring enlarges each year.
The fungus usually lies several inches below the ground and forms a dense layer of mycelium (white hair-like
threads) that breaks down organic matter at the outer edge of the ring. The dense mycelium traps the movement
of air and prevents the penetration of water. This lack of water, air and nutrients causes the grass to yellow or
brown in the ring where the mycelium is the thickest.
As the fungus grows outward and breaks down organic matter, it releases nitrogen. Rapid, dark green growth
of the ring is a result of the additional nitrogen.
1. Mushrooms do not injure the lawn. Simply rake them up and discard them.
2. Aerate the soil. Either remove cores of soil 1-2 inches in diameter or punch holes with a spading fork
the depth of the tines. Aerate at least 6 inches outside and inside the ring, including the ring itself.
Punch as many holes as possible.
3. Apply a wetting agent (surfactant) over the entire ring. Wetting agents allow water to penetrate soil
more easily and deeply.
4. Drench the soil with water from a hose. Sprinklers do not apply enough water at one time. Let water
run out of the hose until there is standing water.
Repeat steps 2, 3 and 4 every three days. Do not skip a step! You should begin seeing improvement in two weeks. Continue the process for at least one month.
You can also remove the sod, mix soil in affected areas in the upper 6 to 8 inches of soil with a rototiller, and reseed or put new sod in the area.
Keep your lawn in healthy condition. Fertilize at least three times during the growing season. Mow at proper height. Water deeply and infrequently.