Question & Answers
These are the most common questions asked of Pinkston’s Turf Services. If you have a question that is not addressed in this section of our web page, please email your question to greenlawns@pinkstonsturf.com and we will get back to you as soon as possible.

Lawn Care Questions:

Question: My yard has a lot of weeds with purple flowers in it each spring. What needs to be done to rid my yard of these weeds and the other weeds I see in the spring months?

Answer: The weed you are describing is called Henbit. Henbit germinates during the fall months and in early spring. Ideally, the best time to begin treatment for henbit and other broadleaf type weeds is in the fall between October 1st and December 20th. Our Winter Weed Control application is designed to control those weeds while they are young and easy to kill. Once spring arrives, we recommend treating with our Spring Weed Control treatment. This pre & post emerge formulation will control the broadleaf weed like henbit and also control the grassy weeds that begin to germinate in the spring. Once the spring application is applied, it will take up to 30 days for all the weeds to die.


Question: I always get crabgrass in my yard during the summer months. When should a preemergent be applied to my lawn?

Answer: Crabgrass is an annual weed, which means, it germinates in the spring from seed, lives one growing season, reseeds itself and dies in the fall when the temperatures drop. The most effective way to control crabgrass is to apply a preemergent chemical before the weed seed germinates in early spring between February & April. Once the crabgrass seed has germinated in late spring, you must use a postemergent chemical to clean-up the weed and then apply your preemergent to control any other late season germinating grassy weeds.


Question: How do you get rid of poa annua in a fescue area?

Answer: Since poa annua is a second cousin to fescue and rye grasses, it makes it very difficult to impossible to clean up poa annua after it germinates without killing the fescue and rye grass that you want to keep. Poa annua must be controlled with a preemergent in late August or Early September before it germinates. Now here is the tricky part, if you apply a preemergent on the shadegrass area, at the above times, you cannot overseed your lawn with fescue or rye. The preemergent will not allow the seed you want to survive to live. In Tulsa we recommend overseeding the lawn with fescue from mid-September to the end of October to reestablish the density of the turf. So you have to choose which issue is more important to you.


Question: My fescue start dying in May this past year. It looked like it got sick, laid down and die. Some of it made it through the summer, but not all. What is the problem? Soil? Shade? Fungus?

Answer: If you recall, we had a very wet April, May, and June this year. Fescue is very susceptible to several fungi that cause the plant to decline or die. Brown Patch, helminthosporium leaf spot, powdery mildew, rust, and smut fungi are just a few that can affect fescue when the air temperatures are between 60 & 85 degrees with high moisture levels, like we had this year. We recommend treating the lawn preventatively with a fungicide before the problem occurs. Start in April and treat once a month until the weather pattern begins to dry and warm up. We offer this service to all of our customers with shadegrass as an optional treatment schedule.
I doubt that you have a soil problem, but you may want to get a soil test done at the OSU Extension Center at 15th & Yale. Shading could be a major problem for your fescue grass, if you have areas in the lawn that are completely shaded all day. All shade tolerant varieties of grass, like fescue, need approximately 30 % to 60 % sunlight to survive well with adequate irrigation during the summer months. If you have a deeply shaded area, I recommend considering trimming up the trees to allow more sunlight to reach the turf or consider using a ground cover type of plant as an alternative.


Question: I have had nutgrass in my yard for years, is there anything you can do at Pinkston’s to help me with this problem.

Answer: There are two types of nutgrass found in the Tulsa area, Yellow Nutgrass & Purple Nutgrass. 95% of the time yellow nutgrass is the one we see and treat. Yellow nutgrass is the easier of the two to control, however, both can be difficult and multiple applications of selective herbicides are recommended. If you are having a problem each year with nutgrass, I recommend one of our Professional Weed Control Programs that are designed to take care of nutgrass problems and other weeds. If you have an extreme case of nutgrass, we recommend adding to your program the Second Preemerge treatment in May/June (refer to the Treatments). This application will help control up to 85% of the nutgrass through the summer months. Purple Nutgrass is a very difficult weed to control, as a result, multiple applications of a selective herbicide that is specifically designed for purple nutgrass is suggested. Lastly, since nutgrass germinates from seeds in the soil that are developed on the root system of the nutgrass plant and there are thousands of such seeds, yearly applications will be necessary.


Question: My neighbor had lime put on their lawn this fall, does that mean I should lime my yard too?

Answer: To give you an answer requires some investigative work first. A pH test must be done to determine the pH level in the yard. Ideally, the pH in your lawn should be between 6.0 and 7.0 for the yard to perform well. Once the pH information is developed, we can then calculate the amount of lime to use to adjust the soil back towards neutral on the pH scale. We use lime when the pH test reveals an acidicity problem. If the test reveals and alkaline problem, we would use elemental sulfur as a soil amendment to adjust the soil. In most cases in Tulsa, we see an acidicity problem rather than an alkaline problem. If you do not know the measurement of pH in the soil, I do not recommend arbitrarily treating with lime. Take the time to get a pH test first! At Pinkston’s, we do a pH test every fall for our customers (free of charge) when we do our Winter Weed Control treatment.


Question: Dallisgrass is overtaking my yard. I put a preemerge down on my yard every spring, but it doesn’t seem to work. Why? What can I do to get rid of it? Help!

Answer: Dallisgrass is a perennial weed that comes up from the root system in the spring like bermuda comes back each year from its root system. Since it comes up from a root system, no preemerge will work to control it. Effectively controlling dallisgrass is difficult because its root system is so deep in the soil and it is a very hardy plant! There are two methods in controlling dallisgrass.

1. Two to three applications of MSMA postemergent must be applied 7 to 10 days apart when the temperatures are around 90 degrees or better. If these applications are applied properly, you will get control of this weed for the rest of the growing season. However, you may see some of it come back the next year because MSMA does not do a good job of killing the root system. Note: The bermuda will yellow during these applications, but will not die.
2. When applicable, I prefer to use Roundup on the dallisgrass to kill the plant. Roundup will translocate from the leaves down to the root system and kill the entire plant within 10 to 20 days. In some heavy dallisgrass areas, two applications maybe necessary. The problem with Roundup is that it kills everything green that it touches; including bermuda, fescue and any other plant it comes in contact. As a result, you will have to replace the grass areas with sod that were treated with roundup after the dallisgrass is dead. Roundup does not harm the soil, so resodding is possible. In yards where the dallisgrass is all over the lawn, you will have to consider the damage Roundup will do to the turf before treating and the cost of sodding afterwards. In those cases, treatment #1 is recommended.

Pinkston can do either application method. A lawn analysis is recommended by Pinkston’s before any treatments are done.


Question: My bermuda struggles in the spring with brown circular spots in the same place each year. What is the problem? It always greens up in those areas later in the summer, but the spring time it just looks bad!

Answer: The brown spots in the bermuda are caused by a fungus that develops during the fall months. This fungus attacks at the root level and it kills the roots during the fall & winter months. When spring arrives you will see brown circular spots in the yard as the rest of the yard greens up. These circular spot will increase in size each year. One method of controlling or fixing the problem is to dig up the soil where the spots are and replace the soil and sod. If you do this extract the soil past the perimeter of the dead area. The best method of controlling this pathogen is to treat the lawn with a labeled fungicide in Mid-September to Mid-October. Any application done after those dates will not effectively control Spring Dead Spot. Spring applications of a fungicide are ineffective. We recommend treating the lawn for two or three consecutive years with the fungicide to overcome this difficult disease. Note: Aeration is recommended to relieve compaction and thatch problems which can contribute to the development of Spring Dead Spot.


Question: I am having a continual problem with moles & gophers. How do I get these animals out of my yard?

Answer: Since moles and gophers are completely different animals, our method for controlling them is different also. Moles feed on all types of insects in the soil, but primarily grubworms. So we recommend treating the lawn and flower beds with a quality insecticide to rid the lawn of the insects a mole likes to eat. In most cases after a period of time, moles will move to another area to find food. Gophers, on the other hand, feed on the root systems of grasses, trees, flowers and shrubs. Since you can’t effectively remove those items from the landscape, you must attack the animal directly by using poison grain or peanuts. Sometimes neither treatment for the moles and gophers works affectively. In those cases, we recommend using trapping devices to reduce the population on animals. The benefit of trapping these animals is that you can quantify that they indeed have been removed from the landscape and you have broken the reproductive process of the animal.


Question: Your literature states that an inch or more of water should be applied to the lawn during the summer months. How do I set my sprinkler system to make this happen.

Answer: Every sprinkler system is different due to head selection, water pressure, and a wide variety of other variables. As a result, it is impossible to give you a blanket one setting fits all answer. I recommend setting your sprinkler up on a fifteen minute interval, place a measuring cup out in the middle of the sprinkler pattern and then measure the amount of water in the cup after the fifteen minutes is over. This measurement will determine whether you need to lengthen the time the sprinkler runs. We suggest watering bermuda two to three times a week, while applying _ inch of watch each time. The most ideal time to water is in the morning from 5:00 AM to 10:00 AM.

Question: What is the proper length to mow my lawn?

Answer: Bermuda should be mowed between 1" to 2 _"; Zoysia should be mowed between 1 _" & 3"; Fescue should be mowed between 1 _ " to 3 _". Mowing heights differ based on your frequency of mowing and the mower type. Never remove more than 1/3 of the leaf blade at one mowing. If you mow more length off than that, you will cause the yard to yellow for a few days until it recovers.


Question: The last time I aerated my lawn was five years ago. Should I aerate my yard again this year?

Answer: Aeration is a maintenance procedure that most definitely will benefit your lawn. A healthy lawn most have good soil that is not compacted and it must have oxygen in the soil to allow the root system to thrive. Aeration relieves compaction of the soil and allows oxygen to go to the root system. Another beneficial byproduct of aeration is that it helps to break down thatch naturally. I strongly recommend aeration on a two to three year cycle!