I cherish my beautiful lawn... which has often been ravaged throughout the...
I cherish my beautiful lawn... which has often been ravaged throughout the summer by lawn disease and fungus. Your recommendation that I NOT fertilize in the spring has helped a great deal. A (pricey) fungicide (Heritage-G) has also helped. In September, I aerated the lawn and over-seeded. The new grass has come in nicely and the lawn looks great. Please forgive the long buildup to what is probably a simple question. I wish to fertilize next week but do not want to use a fertilizer that might be too much for the new grass. Roozen's recommends their "Turf-Trust"... which they claim is good for fungus control but not be used with any other fungicide. I anticipate I will use Heritage-G again next June or July to prevent fungus and lawn disease. Problem? A soil test last August showed that with no fertilization in the prior 9-months, my soil was only slightly short in nitrogen. I usually use a slow-release high nitrogen fertilizer (like Vigoro.) Would that harm the new grass? Do any special concerns arise when the lawn to be fertilized involves old grass and new grass (new, but still full length at this time.)
Montgomery County Maryland
Turf Trust is a slow release fertilizer and should be fine for your new lawn. It is "good for fungus control" because it is slow release, not because it contains a fungicide or has fungicidal properties. We don't know why they recommend not using a fungicide--perhaps they mean that it is not necessary. For more detail than that, you'll have to contact the company from their website.
Fertilizing new and old grass is a common situation as lawns are constantly being overseeded. Once new grass is old enough to cut, you can fertilize with a regular lawn fertilizer and your slow-release fertilizer should be especially safe.
Incidentally, soil tests do not test nitrogen because nitrogen is so volatile that the results are not useful. See our website publication on fertilizing lawns: http://mda.maryland.gov/Documents/HowToFertilizeYourLawn.pdf