View Full Version : Fertilize this lawn now or wait till Fall?

02-20-2006, 11:10 PM
I have this customer with some type of cool season grass (at least it stays mostly green in winter so I assume it is) and I've read that they can be fertilized (fescue that is) in February. Also in Sep and Nov. Well he wants to put out seed in the fall so was wondering if fertlizer application would be recommended now or then or both maybe. If my pics posted, you can see he may need some seed in spring too if it's worth it. I just did a soil test and have results stating a 15-0-14 or EQUIV per 1000 sq. ft type fertilizer is recommended. He's hoping the lawn will thicken up some this spring on it's own in his backyard where it's sparse and shaded moreso. I could use some work right now but didn't want to recommend a fertilizer application unless it will benefit the yard for the spring. Thanks for the help/advice in advance.


02-20-2006, 11:14 PM
This guy looks like he has some problems other than needing a fert application.In the 1st pick I see compaction and drainage problems in the second pic could very well be a grub or cinch bug problem.The other guys on here will help diagnose it also.

02-20-2006, 11:49 PM
If he is not going to reseed until fall I would wait to fertilize then. make sure he plans to do it early sept. so the grass has plenty of time to germinate and get rooted in good before the temps drop in the fall. I also would do a higher nitrogen fertilizer application about a month after the seed germinates.

02-21-2006, 12:04 AM
Some very good replies here. Actually down here in NC, you can reseed all the way until mid October. That can flex a little depending on the rainfall amounts during that time period.

I'd go ahead and apply the fertilizer for now. Make the best with what you have. The fertilizer will be all gone by June anyway. With all those leaves, I'm curious what your pH levels were. Looks like a good lime application would benefit. Good Luck

02-21-2006, 12:41 AM
bump I would like to hear some other evaluations on this lawn please

02-21-2006, 01:08 AM
Thanks for the suggestions. Lawnspecialties, here is an attached adobe of his soil test report. Hope it posts. If not, the pH listed on report is 6.9 and Lime listed as "0" or none needed I assume. Does this appear to be some type of fescue grass?

K&L Landscaping
02-21-2006, 08:31 AM
Look's to me like the back yard is screaming to be aerified! I would really try to sell him on the aerification in the back in March and again in Sept. If the ph is 6.9 you do NOT need lime, fescue grows best between 6.3 and 6.6 ph. This guy will have to understand that this will probably take a while for his lawn to come around. The front lawn looks like about any other lawn around here in the winter to me.

02-21-2006, 09:08 AM
I don't see how you could recognize insect damage from those pictures. I definitely see some dormant bermuda mixed with some fescue in the second picture. Yeah, aerate this spring. If you are planning to do any spring seeding as well do it around 3rd week in March; but you'll probably have to do it again in the fall for best results. Go get some 18-0-18 and you'll be set. Are you licensed for pesticides? :weightlifter:

K&L Landscaping
02-21-2006, 09:28 AM
He doesn't have to be licensed in NC to aerify and spread FERT.

02-21-2006, 08:28 PM
K&L is right on the money. With a 6.9, you'll probably be fine on pH for a couple of years. In the pictures, it appears the lawn sinks a little in that area. If that ground is indeed compacted, continuously standing water is not good. Aerate it for now. Come fall, you might even just till it up. Watch out for that tree's roots.

02-21-2006, 09:38 PM
Don't mean to be negative here but if you can't tell the difference between
a cool and warm season you shouldn't fertilize it until you know for sure what you have. What part of the state are you in? You may want to get a professional spray company to give you a quote and a diagnosis to be sure of what your dealing with. You could also call your county agent.;)

02-21-2006, 10:21 PM
Looking at your soil test results, your calcium levels are fine but your magnesium levels are high. The magnesium is what is causeing the compaction. HM% are also quite low. .56% when they should be around 5%. The addition of sulfur will help reduce the magnesium levels while maintaining the calcium levels. this will improve the compaction issues. The addition of organic materials will also help create porousity and improve air and water in the soil as well as microbial activity. I suggest that the fertilizers to use are Ammonium Sulfate and Potasium sulfate to obtain the sulfur. Core areate first and then apply the fertilizer and topdress with a compost material. Overseed if you like. Elemental sulfur can also be used.

Probable causes for this soil condition is overuse of nitrogen fertilizer and heavy applications of lime, probably dolomitic lime since it also contains magnesium. Dolomitic lime is usually the lime of choice for NC soils but the overuse of nitrogen fertilizers and low organic matter has caused the excess nitrogen to convert to nitrate acid which has leached off the soil carrying the calcium with it. The use of gypsum in this case is warrented to supply future needed calcium + sulfur until the other nutrients come into balance.

02-22-2006, 10:24 AM
Also need to add that your K is very low. The report shows 46 lbs/A, and you should be much higher than that. Your next few fertilizer applications should be high in K.

I would fertilize it now with a equal analysis of N and K such as 21-0-21. This application of fertilizer should also contain a preemergent such as Dimension or Barricade. Do this as soon as possible to prevent Spring weeds.

Then about June 1, you can use a 5-10-31 or equivalent to help with Summer heat stress. After that, you can leave it alone until September when the time comes to overseed.

You do have an area of Bermuda invading the Fescue, which will be an ongoing problem. Unless that Bermuda is chemically removed, it will eventually take over that area of turf. It is expensive to undertake that effort, so the alternative is to just manage around it as much as possible. There are numerous threads here discussing the use of Turflon, Acclaim, etc.

02-22-2006, 05:51 PM
I am not so sure that that is bermuda invading the law as much as it might be dead crabgrass. Extremly hard to tell from the pictures.

Potasssium level should be 90 to 125 PPM on low organic soils. Thats 180 to 250 lbs per acre in a 6 inch layer of soil. You have 46 lbs so you are short about 200+/- lbs of K, or about .46lbs per 1000 sqft. Dont put it on all at once unless you are incorporating it into the soil. Potassium will raise soil Ph some, but not much. Your magnesium levels are 22% and should be around 10-15%. The addition of Sulfate Potassium for your K will help lower the magnesium %, as will the addition of Ammonium Sulfate. These materials will also lower your Calcium % so additional Calcium, in the form of Gypsum might be necessary. Gypsum also contains Sulfur. Calcium displaces Magnesium on a 1 to 1 ratio but Magnesium has a 1.6 to 1 Ph altering ratio to calcium. Meaning Magnesium will raise the soil Ph more than the calcium. Your Ph of 6.9 is because of the magnesium content of the soil instead of the Calcium content.

02-23-2006, 09:08 AM
I agree its difficult to tell from the picture. From my experience though, crabgrass tends to be more "clumpy" and "brownish" during the winter as opposed to bermuda which tends to be more "patchy" and "whiteish".
I'll see if I can figure out how to post some pics.

02-23-2006, 01:46 PM
Your customer does have problems, picture 1 just shows that the lawn is thin. Ask your customer what their expectations are and relay to them that it will take a couple of years to achieve a desired stand of grass. If they want cool season let them know that the only way to thicken the stand is by overseeding, I would recommend powerseeding for a better stand. If they want a warm season grass, sow it this summer when the temp. is warmer for germination. Apply a good starter fert. like 16-25-12 or similar. Warm season grasses such as bermuda or zoysia will not fair too well in the shade. As for how their lawn looks now, it could be thin because of excess wear during the fall when the grass is dormant and cannot repair itself. I also noticed that this lawn is maybe in the shade because of the trees, this is not much of a problem except that if they have alot of leaves have the homeowner rake and pick them up. Leaf compost is good for the soil but too much can be bad on lawns because of the excess mulch will crowd out the sun and nutrients from reaching the ground and grass roots.(Ever see good grass stands in the woods? But the soil looks terrific!) Good luck

02-23-2006, 03:58 PM
SoMo, I am going to disagree with you about the starter fertilizer if he chooses to overseed. The purpose of the starter fert that you suggested is to provide adequate P for root establishment. His soil already had adequate P, altho it probably isnt available to the plants. The addition of Calcium will free up the P making it available to the soil. The Magnesium is what is bonding to the P making it unavailable to the plant. the Calcium will displace the Magnesium lb for lb.Calcium% should be at the high end of the scale for clay type soils with a minimum of 60% and maximum of 80 percent. His Calcium is at 69%, certainly room for raiseing the calcium levels. Magnesium on the other hand should be at the lower range of % of 10% to 15%. His magnesium levels are at 22% so certainly room to lower the magnesium percentage. Magnesium also has more control over Ph values than Calcium so lowering the Magnesium percentage will also lower the Ph, even tho you are adding Calcium to the soil. Since he is also needing to add K to his soil, the K will help raise the Ph. K raises Ph more than calcium also. Again, I suggest that any fertilizer application be of Sulfate of Potash and Ammonium Sulfate, with the addition of gypsum to raise the Calcium levels and displace the magnesium and maintain the proper Ph. The same applies if he chooses to overseed the area. An application of Calcium applied and watered in three days before seeding will insure that the calcium is available to the new grass. If the calcium is available to the plant, so will be the NPK. The use of Ammonium sulfate and Potassium sulfate as well as the gypsum for his calcium source will also insure that Sulfur is there and available to the plant. The addition of any nutrients will lower the percentage of Calcium in the soil, so the addition of any fertilizers, without adding calcium also, is going to lower his calcium percentage below the 69% that the soil test shows is currently in the soil. Calcium loosens the soil and magnesium tightens it up. raiseing calcium levels and lowering the magnesium levels will reduce the compaction of the soil. The closer the calcium levels are where they should be, the more air and water holding capacity you will have in the soil.

02-23-2006, 10:43 PM
that soil is packed, i would aerate and put down lime in the fall

02-24-2006, 10:08 AM
Folks....look and learn from the soil test report....it tells the whole story. I'm absolutely tickled at how you can say to add lime or other fertilizers when the soil test is CLEAR about the soil condition. The minimum suggestion by the State is the get down 1 lb. N (the 7.0 lbs. of 15-0-14) which is a standard suggestion by NCDA when the P & K levels are in near normal ranges (about 50), even though the P level is through the roof......I see 100's of these test a year here in NC and this is typical. In short...........MUDDSTOPPER has hit the nail on the head.