That's what happens when you seed in the spring, though there are ways to control it (Tenacity).

From the looks of it, by the time summer is over crabgrass will have taken over most of your lawn if you do nothing. You can spray quinclorac now to salvage what's left and live with the bare patches until September, or leave it alone and re-do the whole thing in the fall.

Make sure pre-emergent gets put down next spring and every spring going forward so you don't have this issue every summer.

Mushrooms just come and go, though it may be an indication of plentiful water.

You hired him in April to seed, so was it his fault for not refusing to do what a paying customer wanted him to do, or was it your fault for not knowing that spring was a poor time to seed new grass? The problem you're seeing would be expected because spring is when the crabgrass seed is sprouting. It would be expected to get worse in the next few weeks as the temps heat up, because spring seeded grass has not had time to develop sturdy, heat resistant, roots. Whose fault is that for knowing or not knowing?

Normal people would not know about spring seeding, because we get bombarded with advertising in the late winter to spring about putting down seed NOW. That advertising comes from people who sell both seed and the chemicals needed to treat the problems that arise from spring seeding. What you're experiencing this year should never happen again, because you're getting educated about it.

Fighting this now will suck resources from your lawn budget in the fall. Crabgrass dies at the first frost, but you don't have time to wait for that. You need to get seed down (again) at the beginning of fall. For you that's about late August when the summer heat breaks and the evening temps start cooling off. That timing gives you plenty of time to establish grass once and to reapply more seed if it doesn't come in as dense as you would like. You won't have to deal with summer annual weeds at that time, and the grass will have all winter to develop deeper and stronger roots.

Now is a good time to practice good maintenance habits. Here are the basics...

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.

Here's more on watering, because that's the most important factor by far...

Watering: Deep and infrequent is the mantra for watering. This is for all turf grass all over the place. Deep means 1 inch all at one time. Put some cat food or tuna cans around the yard, and time how long it takes your sprinkler(s) to fill all the cans. Memorize that time. That will be the time you water from now on. My hose, sprinkler and water pressure takes 8 full hours to fill the cans. Your time will likely be less. I like gentle watering. As for watering frequency, that depends on the daytime air temperature. With temps in the 90s, deep water once per week. With temps in the 80s, deep water once every 2 weeks. With temps in the 70s, deep water once every 3 weeks. With temps below 70, deep water once a month. Note that you have to keep up with quickly changing temps in the spring and fall. This deep and infrequent schedule works in Phoenix and in Vermont, so it should work for you. The reason for deep and infrequent is to grow deeper, more drought resistant roots and to allow the soil to dry completely at the surface for several days before watering again. If it rains, reset your calendar to account for the rainfall.

Ok, I will probably have to live with the crabgrass for the next few months. I think I would prefer to see green rather than bare dirt. It's just disappointing that i will be losing the grass that I paid for, and will have to spend more to correct the situation.

By "re-doing" the lawn, does that mean Come late August/ September, this will all have to be first sprayed, pulled up, then put down new seed - or perhaps sod?

and the mushrooms are completely normal?

By "re-doing" the lawn, does that mean Come late August/ September, this will all have to be first sprayed, pulled up, then put down new seed - or perhaps sod?

Yes, same process you went through in the spring. I would recommend spraying Tenacity with the seed this time and after 60 days putting down full strength prodiamine pre-emergent. I'll bet there's some Poa seed hiding in there as well.

and the mushrooms are completely normal?

Yes. Possibly a sign of over-watering, but could be just the weather too. Follow dchall's advice on watering .