yes - however if your soil is clayish or severely compacted... then might want to cycle all zones to half inch of water and then start back at the beginning. The idea is to give it time to soak in.

'Hard' areas could use some soil conditioner / soap treatments it sounds like.

DUDE! You are dangerously close to where I grew up (Riverside). I clearly remember your area being mountains where "nobody would ever live there." Amazing where people live now.

When you take pictures of grass, it is best if there is a cloud overhead or when the sun is low on the horizon. Direct sun or flash provides too much contrast.

You're basically on the north facing slope of a break in the coastal range of California. Do you get much direct sunlight in the winter or did they flatten that entire mountain out?

Marathon is a very popular dwarf fescue turf in SoCal. Many people make it work, but many others give up on the high water bills. Most grasses need an inch of water per week when temps are above 90 degrees. Marathon in the heat cannot get by with normal. You're in a great place to be growing Marathon if you want to make it work. Anyplace to the west of you should be find. As soon as you get to Corona, then Marathon starts to get a little more of a hassle due to the heat.

Fescue is a bunch grass. That means each grass plant grows from one seed. If you want more grass density, you have to plant more seed. When the grass plant dies, it does not come back and adjacent plants do not spread to fill in. If you want Marathon to look good every year, you might have to reseed in the fall (early September for your location). When you allow it to thin out, the turf can become weedy, because Mother Nature hates bare soil.

I want to suggest some better adapted grasses for your area. The other two popular grasses in SoCal are bermuda (hybrid Tiff or seeded common) and St Augustine. Both of those are "sod forming" grasses. Sod forming grasses send out either stolons (above ground) or rhizomes (underground) to fill in bare spots. Bermuda is a full sun plant which will thin out in the shadow of a tree, fence, or building. Tif bermuda is available only in sod. This kind of grass is much different than common or seed bermuda. Most people who think of bermuda as a weed are thinking of the seeded varieties. Tif is more like what you see on a golf green or at every sports stadium in SoCal. Generally Tif bermuda should be mowed low twice a week and watered once a week. It should be fertilized once a month through the growing season which is 12 months for you. St Augustine is a coarse bladed turf. The color of St Aug is slightly to the yellow side of a well fed bermuda hybrid. But well fed St Aug is certainly a nice dark green. St Aug is very happy growing in sun or shade. It will be more dense in the sun, but looks fine in 80% shade from tall trees. It should be mowed high every week if it is growing or every 2-3 weeks if you get a summer or winter slow down. You can fertilize it 3x per year (Memorial Day, Labor Day, and Thanksgiving). I use organics and add Washington's Birthday and 4th of July to my schedule. It should be watered weekly in high temps and less often as it cools off.

Neither of those grasses will give you the problems you're seeing with Marathon. In a nutshell, Tif bermuda is a lot of work to keep nice. St Aug is more relaxed but a coarse blade. If you want to restore your Marathon, you'll have to either put down new Marathon sod, which you can do now, or reseed in September. Be sure you get the right Marathon. There I, II, and III. Each one gets progressively slower growing and more dwarfed.

Watering should always be done deeply and infrequently. Deeply means a full inch all at one time. Measure an inch using cat food or tuna cans placed around your yard. Turn on the sprinkler and time how long it takes to fill the cans. That is your target time for every time you water. Infrequently means to allow the soil to dry completely before you water again. Assuming your grass has developed deep roots, the grass should survive for many days after the surface is hard and dry. This is where Marathon in the desert goes bad, because in Temecula and to the east it needs it more than once a week. Marathon must not develop deep roots is all I can think of. But in Anaheim Hills (sea breeze and slightly higher altitude) you should easily get by with weekly watering. When temps drop into the 80s (most of your summer), you should be able to drop back to watering once every 2 weeks. When you water like this it practically eliminates weeds, because weed seeds need continual moisture to germinate. When you don't provide that, the seeds just sit there.

For dry and/or hard areas, wait until you see the results of the can test. I strongly suspect it will be a simple matter of uneven sprinkler coverage. That might require new heads to fix. Also check for water runoff in the hard soil area. If you get that, stop watering immediately. Let the water soak in for 30 minutes and resume. It might take many stop/start cycles to get the inch of water into the soil. But if it runs off, you could apply 3 inches and it won't work. There is a biological reason why soil gets hard, but I'll spare you those details. You can set up the soil to become soft again by spraying it with shampoo. The application rate is 3 ounces per 1,000 square feet followed by an inch of water. It can be any clear shampoo. I like generic baby shampoo. If one treatment does not seem to soften the soil (screwdriver test after you water), then repeat the shampoo in 2 weeks. Repeat as often as you like.

For dead grass areas you'll have to resod now or reseed in Sept.

NEVER ROTOTILL in preparation for grass. That is a vegetable garden practice that somehow has leaked into lawns. It doesn't work for lawns. A few years after rototilling the soil will have settled unevenly leaving a bumpy lawn.

Never cover with a topper or topdressing if that topdressing has soil or sand in it. Why? You'll permanently change your drainage. I have pictures of lawns with an additional 8 to10 inches of topsoil from annual topdressing of 1/4 inch, over 40 years. You won't need anything for new seed anyway. Simply apply the seed to the bare soil and walk on the seed or rent a roller. All you need to do is get good contact between the seed and soil. Then start watering the seed. Watering seed is much different than watering established grass, so you'll have to compromise. You will have to water for the seed and ignore the deep and infrequent rules.

Pro tip: breaks in mountain ranges in California are associated with fault lines, so just be aware.

Again, wow. Far more information that I expected, also much appreciated. So, can I integrate one of the grasses you mentioned about with the Marathon or should I clear it all out first, then start over? Tif you said is harder to keep green? And when I hear (read) St Augustine, I think of thick, viney "spider" type grass. Am I thinking about something different? It feels like your walking on sponges...?
I'll write more later but it's getting late.

Mike

California is in a drought. In your neighborhood microclimate, most grasses are going to need to be watered every other week in the summer. Marathon will likely need water every 3 days to survive. If it gets worse and you are not allowed to water but once a month, the only survivor will be bermuda. So there are some considerations. St Augustine will survive if you can only water every other week. If you let it get up to 12 inches tall, it will likely survive for a month at a time. I keep mine at 12 inches (string trimmer, not mower), and so far this year have not watered it all yet.

Bermuda is not necessarily harder to keep green and dense, it just takes more input in the way of monthly fertilizer. It depends on what you're happy with when you see it.

I have two houses/lawns. Here's a picture of my short-grass St Augustine taken from an altitude of 24 inches.

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That grass is in full shade all day, so it's fairly thin compared to the density in the sun. I'll have to get a close up of that this weekend. St Aug definitely has a different feel under foot compared to bermuda. Sometimes bermuda is spiky under foot. If you're not doing it right it might feel spongy.

dchall...BTW, is there something else to call you or do you prefer your User Name?
I'm learning so much and your time and experience is appreciated. I'm putting out cans tomorrow and will take some pictures in the morning so I can post them. So you can see what I'm dealing with. You're right, I'm spending so much money to water about every three days for the marathon to grass. I would love to only water once a week, or maybe once every two weeks. I can't even imagine that! Looking forward to learning more, as this is my first house with a yard.

I'll share more in just a bit.

Thanks again!

>>dchall...BTW, is there something else to call you or do you prefer your User Name?

He's partial to "Lord and Master."

dchall....
I've enclosed a photo of my FRONT lawn. It's actually doing ok, but there are areas where it's not doing so well. I'll take a picture of that shortly. I don't know how to include more than one photo per message.
Do you recognize the grass shown in the photo? It's taken about 24" away as well. If you DO recognize it, how much he should I be watering and should I let it grow taller than the Marathon in the back yard?

My guess for that picture would be zoysia but there are too many zoysias that I have not seen. You might take a piece to your local nursery and ask. If you don't trust a local nursery, try Roger's Gardens in Corona Del Mar. They used to be good for stuff like that.

All lawn grasses need 1 inch of water applied according to demand for water. Generally...when the temps are in the 90s every day, the lawn needs an inch once a week. Generally...when the daytime high temps fall into the 80s, a lawn will need to be watered once every 2 weeks.

Here's how you do more than one picture...

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