The intermountain west is probably the exception to the rule that KBG needs a lot of sun. KBG seems to do better in shade here. Somebody told me that it has thinner air allowing more through.

80s and 90s should not be too hot for KBG. It gets into the high 90s and even into the 100s here and lawns stay green with regular watering.

Do you know if the water is getting distributed evenly? Is it possible that the water is pooling in the areas that are turning brown (too much water instead of not enough)? It looks like those areas are lower than the areas that are green.

The atmosphere is definitely thinner here, we spend $400 a year on sunscreen! ;->

There's definitely no pooling of water. If anything, I guess those areas could be getting a little less water, but it's affecting 80% of the lawn, and the only consistent factor is shade vs. no shade. Those areas in full sun struggle, those with partial shade do very well.

I have noticed that the culitivar of this KBG is very thin. When I try to grow it to my highest mowing setting, it just gets tall enough to fall over. The blades won't support themselves.

Is is possible that just core-aerating the lawn and over seeding in the thinner areas might help? Or, should I over seed the whole thing?

Do you mulch mow? If your soil is anything like mine, it's almost devoid of organic matter (mine is better now than it was after years of mulch mowing and using coffee grounds to fertilize).

Core aerating may help, especially if the water isn't penetrating deeply. Clay can hold water a lot longer than sand, but it can be tough to get it to absorb the water.

I was only able to water for about 10-15 minutes before it would run off when I bought my house, but I never have runoff anymore. I water in cycles, letting it soak in for an hour per station before watering again. That lets the water penetrate more deeply and helps the grass develop deep roots.

The KBG should be able to do fine on 1.5 inches of water per week if you can get the water to penetrate deeply (and get the roots to follow by making sure the soil dries to at least 4 inches before watering).

The green grass your neighbor has may be K31 fescue. I don't really like it because it tends to get clumpy, it grows at a different rate than the rest of the lawn and I don't like the wider blades. But it does have the ability to develop deep roots and stay green a lot longer (but if it does go brown, it doesn't come back very readily).

Sounds like the first step (s) next spring would then be to core aerate and over seed with the same stuff I have now, then right?

If you're going to overseed, spring is not the time to do it when you have that much go dormant in the heat. Depending on when you have your first frost, it may already be too late to do a fall seeding. You want to leave 6 weeks between seeding and the average first frost and I think that's already here for me (and it's still too hot to seed).

The problem with spring seeding is that the grass doesn't really have a chance to establish before the summer heat kicks in. The problem with fall seeding here is that fall is too short. It seems to go from too hot to snow in a hurry.

I've had my best results from dormant seeding. I wait until it's too cold for the seed to germinate and put the seed down (if possible, just before a good snowstorm hits). The snow melt and the freeze/thaw cycles will get the seed to the soil and it will germinate as soon as the soil warms up enough. There should be enough moisture from the snow melt that you won't have to water.

However, I don't really think your lawn looks like it needs to be overseeded. I think you just need to get the grass to root more deeply.

I don't usually core aerate, but I've been working on getting the organic content of my soil higher so that it will absorb water better (and the worms then take care of the aeration). If your organic content is really low, you may want to core aerate this fall (and maybe again in the spring if it's really bad).

If you want to introduce some grasses into the lawn that will have a similar green period to the KBG but will need a lot less water, you can try adding some native grasses like streambank and western wheatgrass or some introduced grasses like crested wheatgrass. These are all cool season grasses that spread somewhat (but won't out compete the KBG where the KBG does well). They're not as dark green as KBG, but they don't need nearly as much water to stay green.

Great ideas on the pre-winter seeding. I might give that a try, along with core aerating this fall, and see how the grass does in the spring and see if it thickens up at all with the additional room in the soil.

Currently, my water schedule is 3x per week at 2 hours per zone (14 zones.)

I wonder if I split that up a bit and did more of a 2x per week and ran it for 3 hours per zone instead, leaving more days between waterings.

Do you think this would stimulate deeper root growth?

I think that would be a better approach. Watering deeply and infrequently is good for a variety of reasons. It helps reduce weeds because they're less likely to germinate. It promotes deeper root growth. It reduces water loss to evaporation in arid climates (because the top inch or two is what is most likely to be lost to evaporation).

One key thing is to make sure that the water is actually soaking in when you water that long. Those areas that dry out could be drying out because the water isn't soaking in. If that's the case, you might want to water for less time in a zone, then give it time to soak in while watering another zone, and water again.

I just noticed that you water 14 zones for 2 hours each. Do you mean that you water for 28 straight hours? If so, you might want to break up the schedule a bit.

It's best to water at night or in the early morning. Note that many watering guides will tell you not to water at night because it will cause fungus. But in the intermountain west, the air is dry enough that we don't need to worry about that. I usually water from about midnight until about 4 AM. I water each zone for 10-20 minutes (different zones cover different amounts of area) and repeat the cycle 3 times so that the water can soak in better. I don't think the 20 minute zones would be able to run for an hour without runoff, but by breaking it into 3 cycles, I can water for an hour with no problem at all.

On the zones...

I alternate nights. I water the grass zones 1-7 on M Fri Sun, and 8-14 on Tu Thur Sat. each one for 2 hours. It starts at 830pm or so, and finishes mid morning. Keep in mind it's still under 50 degrees by that time all summer long here.

As far as I can tell, I don't get any run off in those 2 hours. We have such low humidity, I'm guessing we lose a lot of water in the process through evaporation as well. But, it's worth investigating a little more.

Thanks so muchf or the help and advice, we'll see how it turns out!

Ok. That makes more sense. I think you're doing things right by watering during those times. You're reducing the evaporation about as much as you can. As you suggested, it might be worth considering breaking into three groups, watering zones 1-5 M and Th, 6-10 Tu and Fri and 11-14 Wed and Sat, watering for 3 hours per zone instead of doing 2 hours per zone three nights a week. I'd also try setting some cans out in the areas that are going brown to make sure they're getting as much water as you think.