Okay, way, Way, WAY, WAAAAAAAYYYYY too much information. Please try to stay on topic. If all your tenant agreement says is "maintain and irrigate," you're screwed. Your definition of maintain and irrigate is apparently different from theirs. It's your opinion against theirs. Your word has nothing to do with it. It's all opinion because you used loose language. If you want to ensure you get 100% crabgrass coverage by July, follow your current plan. If you want to get rid of crabgrass do this... 1. Water deeply and infrequently. You're almost there with the 5-day flood plan. Can you stretch that to 14 days this time of year and gradually work it up to 7 days when the temps get into the 90s? 2. Mulch mow at the mower's highest setting. 3. Fertilize once in the late spring and twice in the fall. 4. WAIT UNTIL FALL to reseed. Crabgrass seed only germinates in the spring and only when it lands on moist soil which remains moist for several days. If you withhold water and allow the soil surface to dry out completely, then you have a shot a not having any crabgrass. But you need a dense turf. Fescue has that problem of becoming less dense over time unless you continually reseed in the fall. So it was not your tenant's fault that you have crabgrass in his lawn.

Man I feel your pain, and you have a very tough battle to fight. To gain control is 3-fold. 1. Is Pre-Emergence which is too late for you. Only reason I bring it up is Halt's is not very good product and pretty much useless to prevent Dallis Grass. 2. For Post Emergence is a two fold at attack. The most effective is digging them up especially when they first emerge. Second line of attack if digging is not practical is using a selective herbicide. Th Employment Prevention Agency took away the best tool we had, MSMA. However Revolver works pretty good but will take a few applications. . 3. Is just plain ole good lawn care to keep the turf tight to prevent the seeds from germinating. What makes Dallis Grass so tough is it is a lot like common Bermuda. It propagates via both seeds and stolons (underground roots/runners?. They produce large quantity of seeds very quickly So fact the seeds can develop in between mowings. This is why mowing frequently is so important. Then there are those nasty Stolons underground you cannot Chances are good all those clumps you have are connected together from the same Mother Plant. This is why it is so important to dig them out as soon as they emerge before they send out Stolons to pop up a new plant a few inches away. So start digging and spraying. It is going to be a full growing season long battle.

i tried baking soda with a little bit of cumin and cinnamon. after 24 hours the leaves turned black. not sure about the rhizomes which is the main part of dallis grass. the st augustine seems to be ok. i'll try it out a few more times and post my results.

First, thanks to Alex, Jake and Andy who responded to my question. Nice to get a good response from the members here in Gardenwood. Dchall, I lived in the Town of Tonawanda since 1969. Moved out to the Town of Boston (Southtowns) 4 years ago. And, I've been out to Plano a couple of times to visit my sister. So, I went from 1/4 acre in Tonawanda to 2 acres of grass in North Boston. I am retired and enjoy my total of 5 acres. I have neglected the grass while working on numerous other projects. I did plant quite a bit of grass this year near the area I am having the biggest problem in, and I will be planting more grass in an adjacent area as soon as the heat subsides. I do understand that using a pre-emergent will preclude me from growing grass until late next year. Trying to kill as much of the crabgrass as possible and overseeding the worst area is not out of the question. I do have a couple of herbicides, messotrione and calcium acid methanearsonate. I am going out today to rake up, cut and bag some of the crabgrass. Yes, I know it is a band aid approach, but I want to see if it gets dark soon.