I'm not an expert but the burnt out area looks like grub damage and the green patches (and what you pulled up) looks like quackgrass. I only know because I have the exact same problem in my lawn. The grubs have already gone dormant so no need to kill them now. If I'm correct, you can use Grub-X in the late spring to prevent them next year. Unfortunately, there's no specific quackgrass killer (ala crabgrass, chickweed, etc.) so you'll have to use Roundup on that. That stuff grows fast and can overtake your entire lawn.

Thanks. This is Eastern PA/NJ border. To be honest I'm not sure what kind of grass that is/was, but I reseeded this fall with Pennington Sun and Shade that has a high% of tall fescue. Watering is with a hose I drag out there.....sometimes. I try to use mostly organic, so milorganite mostly, I used a Scotts organics at some point this year and i have a ton of these little flies around which I'm not thrilled about. I'm not wedded to organic. Last application was early Sept when I seeded. Grass looks pretty good right now. Am thinking about a Scotts winterizer in the coming days. Note this will be the first year I'm winterizing - I used to put high N fertilizer down in early spring but now understand this is a bad move.

I try to leave it a little long when i mow - 3"? Maybe. Towards the high side on the mower height setting.

Shade is an interesting story. Norway Maple out front so the grass tends to go through periods of heavy shade morning and afternoon, plus full sun during the height of the day. The triangle of okay grass that points to the back of my car is in just as much (maybe more) shade than the bad patch.

I thought grubs too, but a neighbor suggested a fungus might be the cause, but I'm tempted to treat for both. I actually did try some fungicide this year but I think it was well after most of the damage was done.

Thank you!

If you had crows circling your yard earlier in the fall (or moles or skunks) it's definitely grubs. Before I knew I had grubs I had crows constantly flying around, little did I know that they somehow know they're under the grass and will dig up the lawn to eat them.

White flies can do serious damage to a yard & often misdiagnosed. If tiny flies come up with each footstep, you probably just need to do some spraying. They aren't difficult to control.

Maybe white flies are different up there, but I've had white flies in my yard for 25 years. I notice them when I mow in the late afternoon and the sun is just right.

I'm going to attach the basics of lawn care for you to peruse.

Basics of Lawn Care

After reading numerous books and magazines on lawn care, caring for lawns at seven houses in my life, and reading numerous forums where real people write in to discuss their successes and failures, I have decided to side with the real people and dispense with the book and magazine authors. I don't know what star their planet rotates around but it's not mine. With that in mind, here is the collected wisdom of the Internet savvy homeowners and lawn care professionals summarized in a few words. If you follow the advice here you will have conquered at least 50% of all lawn problems. Once you have these three elements mastered, then you can worry about weeds (if you have any), dog spots, and striping your lawn. But if you are not doing these three things, they will be the first three things suggested for you to correct.

1. Watering
Water deeply and infrequently. Deeply means at least an inch in every zone, all at once. Infrequently means monthly during the cool months and no more than weekly during the hottest part of summer. Do not spread this out and water for 10 minutes every day. If your grass looks dry before the month/week is up, water longer next time. If that does not work, then you might have to water more than once per week during the summer's hottest period. Deep watering grows deep, drought resistant roots. Infrequent watering allows the top layer of soil to dry completely which kills off many shallow rooted weeds.

You will have to learn to judge when to water your own lawn. If you live in El Paso your watering will be different than if you live in Vermont. Adjust your watering to your type of grass, temperature, humidity, wind, and soil type. It is worth noting that this technique is used successfully by professionals in Phoenix, so...just sayin.' The other factors make a difference. If you normally water 1 inch per week and you get 1/2 inch of rain, then adjust and water only 1/2 inch that week.

2. Mowing
Every week mulch mow at the highest setting on your mower. Most grasses are the most dense when mowed tall. However, bermuda, centipede, and bent grasses will become the most dense when they are mowed at the lowest setting on your mower. In fact there are special mowers that can mow these grasses down to 1/16 inch. Dense grass shades out weeds, keeps the soil cooler, and uses less water than thin grass. Tall grass can feed the deep roots you developed in #1 above. Tall grass does not grow faster than short grass nor does it look shaggy sooner. Once all your grass is at the same height, tall grass just looks plush.

3. Fertilizing
Fertilize regularly. I fertilize 5 times per year using organic fertilizer. Which fertilizer you use is much less important than numbers 1 and 2 above. Follow the directions on the bag and do not overdo it (unless you use organics in which case you may overdo it without fear of hurting anything).

At this point you do not have to worry about weed and feed products - remember at this point you are just trying to grow grass, not perfect it. Besides once you are doing these three things correctly, your weed problems should go away without herbicide.