I’ll send some pics when I get home, but here’s the gist of it.

I’ve got a few issues this year. As background, I overseeded/aerated last fall, applied compost as topdressing. Everything looked great. Followed the 10-day rule, waited until spring up to fertilize (late May here in the SF Bay Area). Summer comes, and bam…problems.

The first problem is something I’ve seen in years past, although not this bad. I’ve got a few spots where the turf and soil is actually receding from the concrete it’s up against (The pick will illustrate this better). That area is, well, dying, it appears. It’s almost as if the turf was a wet sponge, and is not ‘rug out’. The area does get plenty of water though, as far as I can tell.

The other issue is that the grass, in spots, is flourishing, and in other areas is not. Some areas are exploding with lush green growth, and some don’t grow at all and exhibit rust. I don’t know what is causing this, but I know what is NOT causing it. It’s not uneven fert spreading, and it’s not uneven watering, and it’s not sun vs. shade exposure either. The pic will better illustrate this when I upload it later. I had a soil test done last fall, and it looked fine…no major deficiencies.

My thinking is that because my soil is clay, it needs more than 1 aeration/year. It seems that as soon as the spring rains stop, this problem starts for me…every year. Some years are worse than others, but if part of the grass is growing, and the conditions are the same in other areas of the turf, then why shouldn’t ALL the grass grow like that…or, conversely, why doesn’t all the grass fail to thrive?

Not sure if compaction could be the cause, but I would think that, next year, aerating twice a year could do nothing but help the turf. And I don't think there is anything I can do at the moment except wait for the fall aeration to hopefully get the lush back.

Thanks for any advice,
Matt

Different growing characteristics hint to different grasses, but we need pictures first.

Ok, here's a pic of the crack, the turf pulling away from the pavers

Heat. The pavers are hotter than the soil is because the brick attracts and retains the suns heat.

Then .... look at how short you are mowing!

I can understand the heat theory...but what can I do, at this point and in the future, to prevent it?

On the mowing, it's not from mowing low...it's from not thriving. At one point I did mow to the middle setting, in early spring, to get rid of rush...and some of those areas never grew back. They are lighter shades of green then the rest, as you can see.

Should I fill in that gap with topsoil, maybe mixed with some peralite to help retain moisture? Not sure what else I can do at this point.

Thanks all.

Water these spots by hand as often as needed. As it cools down, reduce the amount and frequency.



Definitely NOT Perlite. That is used to provide drainage. Add top soil and a little peat moss to retain moisture.



Yes it is. It is not thriving because of your practices - mowing low during warm temps is bad practice.

Here .... I mowed yesterday at 3.25" tall. We've had record breaking heat for days at 90 plus degrees this year.
It rained Friday night and today is Tuesday. Four days in 90 degree weather without any irrigation. This is what mowing tall during summer will produce.
(please scroll down below the picture.)



------------

Now I'm too lazy to type out the rest of my thoughts tonight.

I've kept something private for a long time, but this is a perfect opportunity for me to do this instead of typing.
I want you to read the first 3 pages of this here https://sites.google.com/site/garycinchicago/
The first three pages is exactly what we are discussing here right now .... my link is a work in progress. Like I said, I'm lazy and hate to type.




What is "rush" ?
How does mowing taller get rid of this rush?



This has unwanted grassy weed written all over it. Again going back to your practices and bad habits.

got it. Thanks Gary. I'm using a soaker hose on that one area to see if that works.

'rush' should have been 'rust'.

I don't think it's a weed, it's just that I scalped it and it's not growing. I sure hope it's not a weed, because it's basically over half of my lawn. It will pick up in Sept when the cool weather hits.

The lawns do get a lot of foot action (three little boys' worth). I'm thinking that aeration in the spring would help as well.

FWIW the last two years (previous to this one) I always mowed at the highest setting, from the first mow in spring until the last mow in fall...and the same problems, in the same spots, still occurred. That's why I'm thinking that some of the spots may be caused by mowing low, this year, but what about previous years?

Thanks Gary for providing that link as well.

Grows like hell in spring, bright juicy green color ... burns out in summer heat, comes back to life in fall?



Do you see seeds in this area in spring?

nope.

Nothing like that. Those areas are not weeds. The areas look very nice in the spring...then they just turn lighter green and don't thrive. Dead spots as well. Patchy. Ground there is really hard...like it's not getting enough water, or it's compacted.

It is getting enough water, though. I used the tuna can test and water infrequently and deeply.

Besides, it couldn't be weeds in that large of an area anyway. Besides the fact that there are zero seed heads, they would have to get thru the apps of Halts in the spring that I've applied each year.

I do get rust in these areas in the spring...every year. Nothing I can do I don't think. This is even before I have watered at all...just nature. So I get a blanket of orange, and some spots never recover from it. These, I think, are the same spots that are now hurting. But I thought rust did not harm the grass?

I apply liquid aerator every three months, topdress with compost every time I core aerate.

What do you think about aerating in the spring as well as the fall, to help with my clay soil?

Thanks Gary!

Matt

As a follow up question...

My soil is clay..at least more clay than loam or sandy. Last couple of falls I've topdressed with finished compost.

Should I do the same this year, or use something else/mixture to help break down the clay?

Thanks!
Matt

Tall fescue .... hmmm, I'm wondering if you aren't seeing some brown patch disease?

could be...not sure that the causes are. I"ll have to look at one of the resources here.

Can you point me in the right direction Gary? Thanks.

It would be great to figure it out and not look at a beautiful lawn in the spring and fall...and a struggling lawn in the summer.

one thing that may help...

Whatever is happening, it happens quick, like within a few days. At the final stage, the existing strands turn basically a straw-like color...crunchy and hard.

It happens each summer, regardless of mowing high, or a little lower. And the grass always recovers each fall after aeration.

I can take some close ups of the 'straw like' patches tomorrow.

Hey Matt ... look at this link http://www.cals.ncsu.edu/plantpath/exte ... Fescue.htm

Look at the pictures on the right, numbers 1, 2, and 3. You can click them to enlarge.
Have you ever noticed those lesions on the grass blades in the early stages before it goes completely brown?

Gary, that's not what I see.

I don't see those types of legions one the blades..it's more of an overall yellowing/straw color, not the defined patterns as in figure 1.

Also, I don't see the circulat patches of struggling blades, more of general areas than a sharp definition.

just noticed one other thing...

I did the tuna can test this morning...turns out I was only applying about .1/2i inch/week, instead of the full 1 inch. That could be the problem right there, because this all starts when the weather starts to get warm.

The front yard though, where that pic is from (not the pick of the pavers) was getting a full 1 inch/week.

EDIT

This is what I see every late spring...these areas then turn progressively lighter, then straw like and thin. The turf there simply stops growing.

http://s224.photobucket.com/albums/dd197/mchad21/?action=view&current=IMG_1635.jpg

and here is a link to my soil test from last fall

http://s224.photobucket.com/albums/dd197/mchad21/?action=view&current=soiltest.jpg

Matt let me sleep on this - I'm all confused right now. Let's see what GWG says about the TTTF.

ha ha...you think YOU'RE confused...!!

Thanks for all the help Gary. I really appreciate it!

EDIT: Another piece of info...my blade could use a good sharpening. A little bit of tearing on the grass blades..not sure if that makes a difference. I do start each season with a sharp blade and try to keep it sharp throughout the year.

I'll try and take some photos of the grass blades to show the state, but mainly they look rust color with no spores...just faded orange.

Just got back from a 10 day vacation, so I'm catching up on house/lawn duties. Let me clean some things up and we'll see if we can't shed some more light on what's going on.

Have you done a soil structure test yet? It would be interesting to see if you really have as much clay as you think. Also, your soil test looks great. A bit high in pH, but nothing to worry about.