Grass near the pines

[lawman]

I have some 25 foot pines that border my yard. They are mulched with a brick border around them. I am noticing this year that the grass near these trees got yellow. Wondering if I need to add something to the soil next spring to keep the area from yellowing again?

[LwnmwnMan2]

Are the pines causing too much shade now?

Do you have sod or was the yard seeded?

[lawman]

partial sun...sodded.

[CAMAN]

The acidity of the soil is probably getting too high. Best thing to do is take a soil sample and get the PH checked. The U of M will do it for free, otherwise many hardware or garden stores carry them. Most likely you will need to lay down an application of lime.

[Dotch]

Checking the U of M's Soil Testing HSOforum, the U will charge you $15 for the regular series which is probably sufficient in your case. The pH being low or acidic is a possibility. Potassium would be another possibility since the soils in that area of the state tend be lower in potassium and the deficiency can be amplified by lack of moisture, something much of southern MN had at one point or another during this past spring & summer. Adequate watering where the trees could be competing for moisture may also be important if it is/was a potassium deficiency. We've seen potassium deficiency here in the lawns and most of the potassium levels are decent. It was influenced by the dry early spring. This isn't the first time so it can be seasonal. This link to the U of M's Soil Testing Lab will give you the info you'll need.

http://soiltest.cfans.umn.edu/