Thanks for your question.  I want to give you as accurate an answer as I can.  For me to do that, I would like you to take a picture of the complete soil report and send to us.  Many thanks for doing this.

Thanks for sending us your soil reports and your patience in awaiting our response.

Both of your two reports are quite similar so let me make a few comments that will pertain to both:

1). You have medium textured soils. This is great lawn soil. Most soils in Washington County have soils with a high sand content. Yours does not. I suspect this is related to relatively high organic contents (5.5% and 4.7%) in both soil samples.

2). The pH values are acceptable for good turf growth. No concern here.

3). Both reports suggest nitrogen amendments of 1 pound nitrogen/1,000 square feet. This can be dealt with via an appropriate fertilizer.

4). Both reports indicate high phosphorus levels. No real concern here. Phosphorus content of soils can fluctuate greatly, sometimes over short periods of time. Although the reports suggest phosphorus additions, you will find few if any lawn fertilizers that contain phosphorus. This is compliant with Minnesota state law. If you are not already doing so, I would suggest that you or your lawn service leave any grass clippings on the yard after mowing. These clippings will quickly decompose and return phosphorus to the turf. This is certainly a more natural way to elevate the phosphorus level than via chemical fertilizers.

5). Potassium levels generally are not major factors for lawns. Still, some potassium amendments should be made via fertilizers.

One report suggests a fertilizer with a ratio of 2-1-2 and the other report suggest a fertilizer with a ratio of 2-1-4. It really does not make good sense to purchase two separate types of fertilizer. Rather it would be easier to get only one type.

As a volunteer Master Gardener of the University of Minnesota, I cannot recommend any specific commercial product. However, I did look at the websites of various big box stores, (e.g., Lowe’s, Menards) and found that a lawn fertilizer with a composition of 32-0-4 is available. I would suggest using this.

As mentioned at the bottom of your reports, “…it is best to apply the amount of nitrogen required and compromise some for phosphate and potash”. This is what you should try and do.

Apply 2.5 pounds of this fertilizer to every 1000 square feet of lawn. You will then be applying 2.5 x 0.32 = 0.8 pounds of nitrogen, and 2.5 x 0.04 = 0.1 pounds of potash per 1,000 square feet of lawn. This will be very close to meeting the recommended amount of nitrogen (1 pounds/1,000 sq. ft) but is below the recommended amount of potash. I’m not overly concerned about this as the potassium levels in the two samples are between “medium” and “high”. Meeting the nitrogen recommendation is the most important. Given all the circumstances, it might be the best and most convenient thing for you to do.

I would suggest that you repeat the soil sampling in early fall (late September). Please send copies of the reports to this same thread of communication. I will not completely close your question at this time. If you do this, we can reassess what types of fall fertilizers, if any, might be applied.

One final point. If you have new grass growing, do not apply fertilizer to them until you have mowed this new grass at least twice.

Thanks again for your patience. We look forward to hearing from you again regarding your lawns. Good luck