dead grass under Spruce tree - Ask Extension
I am wondering why the grass is dead under this spruce tree? I read on google that its because the needles of a conifer tree are naturally acidic, an...
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dead grass under Spruce tree #878757
Asked July 25, 2024, 2:48 PM EDT
I am wondering why the grass is dead under this spruce tree? I read on google that its because the needles of a conifer tree are naturally acidic, and as the tree sheds each year, the needles fall to the ground and cause the soil around the tree to become more acidic. Is this the case here? Is there a way to help the grass bloom here? Would testing the soil, with a soil test kit, help the grass to grow here?
Dickinson County Michigan
Expert Response
Hello Jessica,
Needles from evergreens take many, many years to acidify soil and are not likely to be at issue this far from the tree. Grass is very tolerant of different pH soils.
More likely is the irrigation in the area— the tree could be blocking the sprinkler( and this isn’t good for the tree either if the sprinklers are wetting the needles- that can lead to fungus on the needles).
To see if your irrigation is evenly applied do the “catch can test” as discussed here. Be sure to place several cans or cups, all the exact same size, in the green lawn area as well as in the brown lawn area.
https://extension.colostate.edu/docs/pubs/garden/irr-audit-tutorial.pdf
If you do an irrigation audit and find the area is getting the same amount of water, and the same amount of sun, then check if the area is sloped at all. Lawn on a slope drains faster than lawn growing on level soils, and the slope needs more frequent, slower watering.
Also check how hard the soil seems packed down in the brown areas as compared to how the soil is in the green areas. Compacted soil will not allow water to absorb into the root zone easily.
Lastly, does the browning grass seem to be a different kind than what is growing elsewhere- thicker, wider or thinner leaves, coarser or finer in texture? Is there more thatch at the base of the grass plants in that area?
If all is still a mystery, please attach a couple close up pictures - one where the green and brown grass meets, and one of the brown grass, taken from about 12-15 inches away so we might be able to see some details.
Also, let us know your finding on the catch can test, and the other things you checked as described here.
Needles from evergreens take many, many years to acidify soil and are not likely to be at issue this far from the tree. Grass is very tolerant of different pH soils.
More likely is the irrigation in the area— the tree could be blocking the sprinkler( and this isn’t good for the tree either if the sprinklers are wetting the needles- that can lead to fungus on the needles).
To see if your irrigation is evenly applied do the “catch can test” as discussed here. Be sure to place several cans or cups, all the exact same size, in the green lawn area as well as in the brown lawn area.
https://extension.colostate.edu/docs/pubs/garden/irr-audit-tutorial.pdf
If you do an irrigation audit and find the area is getting the same amount of water, and the same amount of sun, then check if the area is sloped at all. Lawn on a slope drains faster than lawn growing on level soils, and the slope needs more frequent, slower watering.
Also check how hard the soil seems packed down in the brown areas as compared to how the soil is in the green areas. Compacted soil will not allow water to absorb into the root zone easily.
Lastly, does the browning grass seem to be a different kind than what is growing elsewhere- thicker, wider or thinner leaves, coarser or finer in texture? Is there more thatch at the base of the grass plants in that area?
If all is still a mystery, please attach a couple close up pictures - one where the green and brown grass meets, and one of the brown grass, taken from about 12-15 inches away so we might be able to see some details.
Also, let us know your finding on the catch can test, and the other things you checked as described here.
