For cool season grasses, the answer is nothing. Encouraging growth when the grass is stressed is counter-productive.

Wait for the cool weather to arrive and apply most of the season's fertilizer needs then. Lots of decent ways to skin that part of the cat. I apply 20 lbs per thousand of organic fertilizer in Sep and Oct then one pound per thousand urea after the first hard freeze. Then, next spring I fertilize, once for most areas, again. Then nothing while its hot.

"wondering what I can apply to keep the lawn green,and healthy without a high N?"

Water.

As rcnaylor said, you don't want to encourage it to grow. Just maintain it.

Most home owner fert. have quick release N. If you have a lawn and garden center near you they might carry a fert. product that has a slow release N. Your other option is to put down lower apps. of N more often. Feeding your lawn with 1 lbs per 1000sqft of N in July is not wise, but 1/4 lbs of N would do the trick. Another option would be to go organic like Milorganite.

If you have irrigation you can fertilize in the summer in MA zone 6, or if mother nature provides it.

In lieu of a soil test, you can apply at half the rate, Lesco 18-24-12 if you must fertilize in the summer.

The key to fertilizing cool season grasses in the summer is at half the rate and keep the turf irrigated if mother nature does not provide.

Where exactly are you located? (zip code will work)

auteck,

Hi,my zip is 02767 half way between Boston and Cape Cod.I do have an irrigation system and will probably use some type of organic fert like alfalfa, corn gluten or SBM. I'm a little nervous about Milorganite not so much due to the content but more so of the aroma.

Do you know of a good source for calcitic lime?

Thanks
Al

Jonathan Green Mir-A-Cal or Mag-I-Cal are excellent Calcitic limes, and are carried by many local garden centers. Some Lowe's are beginning to carry Pennington's Fast-Acting Lime, which is Calcitic.

Don't be turned off by the price - both are 10X more potent per lb, so you need 10X less of it. Many times, it is cheaper than the dolomitic junk that the big box stores carry.

andy10917,

Thanks for the info, I will look for those products.

Al

I would not fertilize in the hot months of summer unless you are totally committed to the rather large expense of keeping the lawn out of dormancy. Any feeding after 6/15 sets your lawn up for a battle between dormancy and active growth. I wrote an Article (below) on the subject of preparing the lawn for summer heat.

Here is a link that might be useful: Preparing Northern Lawns for Summer

Andy,

Great article. But, I don't allow my lawn to go dormant. I spend the time and money to get it looking good in the spring so I might as well keep spending to keep it green all summer. I keep a very close watch on how the grass looks and water deeply before the color starts to take on a bluish hue. I'm thinking that something like CGM will be my best bet for summer fert.

Al

Shhhh!! Lots of us don't let them go dormant - especially in the first couple of years after a renovation.

By the way, if you want more info on the Calcitic/Dolomitic differences, try the below Article.

Here is a link that might be useful: Lime and Your Lawn