Recommended nitrogen-only fertilizer for bluegrass - Ask Extension
Hello, I recently had a CSU soil test performed for my backyard. It shows very high levels of P and K, but very low N (soil report is attached). In th...
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Recommended nitrogen-only fertilizer for bluegrass #927784
Asked April 07, 2026, 11:04 PM EDT
Hello, I recently had a CSU soil test performed for my backyard. It shows very high levels of P and K, but very low N (soil report is attached). In the past I've typically used a "balanced" slow release fertilizer. What is your recommendation for a nitrogen-only fertilizer? Is there one that has a low risk for burning the grass? Thanks!
Larimer County Colorado
Expert Response
Hi Brian,
Fortunately, this is a very normal soil test and nothing to be concerned about. Nitrogen is a hard nutrient/element to test for because it's incredibly mobile. The lab tests for nitrate (NO-3) and the levels change so rapidly. The number you receive in the morning would be different than what would detected in the afternoon.
That said, nitrogen is always the nutrient that is lacking and that turf needs most. Because it's so dry, continue using the organic fertilizer that you have used. The organics will always have added P and K since it's derived from organic materials. The only "all nitrogen" fertilizer is urea, which is 46-0-0 and can burn lawns, especially if they aren't watered in.
So use the organic and water it in with 1/2" of water. Some of the organics, like Richlawn, have a little big of quick-release nitrogen attached to the granules. That gives the grass an immediate greening.
Fortunately, this is a very normal soil test and nothing to be concerned about. Nitrogen is a hard nutrient/element to test for because it's incredibly mobile. The lab tests for nitrate (NO-3) and the levels change so rapidly. The number you receive in the morning would be different than what would detected in the afternoon.
That said, nitrogen is always the nutrient that is lacking and that turf needs most. Because it's so dry, continue using the organic fertilizer that you have used. The organics will always have added P and K since it's derived from organic materials. The only "all nitrogen" fertilizer is urea, which is 46-0-0 and can burn lawns, especially if they aren't watered in.
So use the organic and water it in with 1/2" of water. Some of the organics, like Richlawn, have a little big of quick-release nitrogen attached to the granules. That gives the grass an immediate greening.
