Question
Hi,

I have Kentucky blue grass (in Denver).  most of the lawn is light green, but the new sod that I planted last year is nice and deep green.  I added some 21% nitrogen last week, but it is still lighter than the sod areas.  I'd like them to match.  any suggestions?

Thanks,

Kevin

Answer
Hi Kevin,

Usually a 20+% nitrate feeding should equalize the green-ness of a lawn consistently.  With cold nights in Denver, the process may simply require more than a single week, so wait and see.

Also, with any particular grass-type or specie (such as KYB), there are, these days, any number of patented 'name-protected' hybrid cultivars or 'varieties'.  Although these are of the same species, some have been genetically engineered to perform in certain ways in regards to growth, drought and disease resistance and general appearance.

When you plant one of these new super-hybrids next to old-stock,...sometimes the differences in green-ness (however optimized by chemical applications), texture, height, growth-rate,...etc. will be visible to anyone paying attention. So, if your sod was not an exact match for the established lawn, there may be these genetic differences contributing to what you see.

Using a fertilizer with ionic IRON may also help to green-up areas equally.

You may eventually let the entire lawn become 'Nitrate Starved', so that all areas exhibit a minimum green-ness and then re-feed with high Nitrate to see how things green-up.  This  test might verify any genetic differences or at least tell you something about how consistent and uniformly your lawn can and will green-up.

Otherwise, there may be localized differences in the top-soil or drainage/leaching scenarios contributing to the color differences.

 Especially with hot days (above 85 degrees),....Top-dress any problem areas with a few bags of commercial potting soil and/or compost to see if this can balance things out and be sure every area is getting equal treatment as far as watering and sun-light is concerned.

If problems persist, consider using an alternative grass-type.  Tall Fescue cultivars are generally recommended for your area (and whatever the crew at CSU is using for their excellent campus grounds!)

Good Luck!
__ JHG