Unfortunately, spring is not a good time to seed cool season grasses. Late spring is even worse. Depending on how thin and how big the thin spots are and how much of the grass is KBG, it may fill in on its own. If not, you'll want to overseed. I was going to ask if the company offered any kind of guarantee, but it sounds like they took off on you anyway, so it's probably moot. I'm afraid you might be too late for a fall seeding in your area. Do you know the date of the average first frost where you are? Wisconsin is a pretty big state, and there is probably a huge difference from one part to another. If you're in southern Wisconsin you might have time for an overseeding, but you want about 6 weeks before frost to do it. If you have time to seed now, you want to cut the grass as short as you can, and either core aerate or slit seed. You want to keep the surface moist until the seeds germinate, so if you're not getting any rain, you'll need to water a couple of times a day. Once the seed germinates, slowly increase the amount of water you apply each time you water and decrease the frequency. The ultimate goal is to apply an inch a week all on the same day. If it rains, you need to adjust the amount you water to take the rain into account. If it's too late for a fall seeding, your next best option is a dormant seeding. For that, you wait until it's too cold for the seed to germinate and overseed. The freeze/thaw cycles and the melting snow will bring the seed into good contact with the soil. When it warms up enough, the seed will germinate. You won't get as much germination as with a fall seeding because you'll lose some seed to birds and insects, some may germinate then die in a freeze, some may wash away, etc. You'll probably still fare better than trying to seed in the spring and keep it alive through the heat of the summer. If you're far enough north and the summers are mild, spring seeding may not be as bad, but from the description of what happened this year, I think you're better off not trying a spring seeding.

Dear SusanB Thank you very much for your inquiry. I do not want to confuse this establishment issue and perhaps I was not very clear. The straw mulch you will here people refer to is used when you establish grass from seed, not sprigs or sod. I use the word straw because I do not want anyone to use alfalfa hay as their mulch source. I hope this helps clear up any confusion. Again, thanks for the question and let me know if you have more. Respectfully Trey Rogers The Yard Doctor

There are so many variables - soil type, atmospheric humidity, temperature and some others - that it is very hard, probably impossible, to come up with rules for watering. IMHO, 2 gallons or so per week delivered by soaker hose is not likely to be nearly enough unless there has been a great deal of rain. The browning needles are likely an indication of too little water. It isn't tremendously accurate, but reaching down to the root ball with your fingers and testing for dryness is better than relying on some sort of formula. If the root ball feels dry to the touch, water it with a hose. 45 minutes as the tree guy said seems pretty reasonable and I doubt very much if he was talking about 45 minutes worth of soaker hose. Another thing that is very helpful for summer planted trees is to spray them with a fine mist such as that produced by a Fog-It type nozzle. This lowers the temperature, increases humidity and slows transpiration of moisture even if none is directly absorbed. This can be done several times a day. For large trees at this time of year and assuming decent soil drainage, under watering is usually a greater danger than over watering.

Since you're using these mysterious "centimeter" measurement thingies, you're not in the States. So you might actually have clay, or could have very compacted sand or silt. All three react surprisingly similarly. Spraying with any clear shampoo or baby shampoo (in the States, I recommend White Rain, Suave, or generic baby shampoo as they're all very cheap, but I'm not sure what brands are available anywhere else) at about 50 to 75 grams per hundred square meters will, over time, sometimes help loosen the soil. You can repeat that monthly. Exact amounts aren't critically important and moderate overapplication won't do any harm. If the tight soil problem is chemical, the shampoo will help, but correcting the soil will help more. A good soil test would help determine what resources require rebalancing. Unfortunately, I'm unfamiliar with the quality of any soil testing labs outside the United States. 3 mm pebbles can be ignored, they won't get in the way and the grass or plants will simply send their roots around them. 30 mm is kind of large. If copious in the soil, I'd try to clear them down to at least 10 cm depth if you can without killing yourself. You don't need to get every single one, just most. With an enormous amount of rocks, it might pay you in terms of time and energy and stress to have the property power raked and then box bladed. Properly done, power raking will remove the rocks for you, and box blading will even everything out. I'm generally not a fan of excessive soil disturbance because it damages (or destroys temporarily) the soil biology and ruins the natural drainage channels. However, heavy rock infestation is an exception to that rule and in this case I have no objections. Done once, the soil will recover (full recovery can take three years, but most will complete in a year, tops), and that's that.