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.

Should have kept that tree. Cool season grass like fescue prefers does well in afternoon shade during the summer. Zoysia is a warm season grass and it grows most actively when it is hot. When it is cold is is dormant. The time to plant fescue seed is in the fall. Not now. The time to plant zoysia seed is never since you need a perfectly prepared pure soil and full sun seed bed to have success with zoysia seed. The zoysia if encouraged will more than likely eventually choke out the tal fescue and you will have all zoysia later down the road.

Biggest advantage is preventing thatch buildup. There is only one real long term solution for heavy clay soils, well two if you consider replacing it. Adding lots of coarse sand is the only long term solution. Adding compost helps in the short term, but it takes as much compost as sand to do the job. However compost always decomposes and leave you right where you started. There are other advantages to top dressing like leveling, adding nutrients, but thattch is the biggie.

When I remove grass, I don't do so in order to replace it with a different cultivar of grass, I put in another flower/veggie bed/conifer bed instead. My goal is to pretty much get rid of all lawn grass - and all annual grasses (ha, wish me luck with that!) - so that the only grasses in my garden are the lovely ornamental grasses. I've been working towards this goal for about 20 years now. So, I obviously don't know anything about sheep fescue but from what I just read it seems as if it would be a good alternative to Kentucky Bluegrass, etc. in terms of drought tolerance and hardiness. Not sure what you use this area of your yard for, but one thing to take note of is that the leaves are supposed to be rather tough and sharp, so, at least from that description, probably not the turf grass on which you would want to go barefooting! Also, it apparently isn't good for high traffic areas as it doesn't tolerate a lot of foot traffic - recommended for a naturalized area with wildflowers and such scattered through it. Here is some info about fine fescue grasses, including sheep fescue, from the Colorado Extension Service which you might find helpful: Fine Fescue For Lawns. Holly