Maple seeds (called "samaras") are best harvested when the papery wing part of the seed turns brown, but the thick fleshy part of the seed is still slightly green and not dried out. They need to be stratified, which means they must endure a period of cold. What I do is harvest the seed, break the pair of seeds in two, and then plant them in a shallow 4" garden pot - cheap plastic will do. Do not plant them deeply. You may want to cover the pot with some wire screening to keep out the squrrels and chipnumks if you have a problem with those in your area. Plant as many pots as you want and then find an area for them to spend the winter. They need to be exposed to the cold and rain. In the spring you should have new maple seedlings come up. If you don't see seedlings, don't give up. Sometimes it takes 2 years for them to sprout. Then just transplant the baby trees to whatever part of your garden you wish. Easy! P.S. They can grow for a whole year in that 4" pot if necessary.

From the info provided, it's really not possible to determine exactly what the problem(s) may be and therefore what you need to do to correct them, but here's a few things to consider: 1) Clay soil has an unfortunate reputation. Yes, it is difficult to work with, can be rock hard when it dries out and may provide iffy drainage. But it also tends to be nutrient rich and also binds applied nutrients (fertilizers). Drainage is probably the most important consideration and hopefully the nurserypeople planting the trees accounted for that - a very wide but quite shallow planting hole and with the top of the rootball slightly above the existing soil surface. Any backfill or mulch should have been used to gradually mound up to the top of the rootball. 2) Timing of the planting. Planting trees in the middle of summer when temps are at their highest is just going to be very stressful and bound to create transplant shock. That's likely what the initial wilting reflected. 3) Adequate watering. I've not used the gator bags myself so don't have any firsthand experience on how well they work. But newly planted trees need a LOT of water and good sized trees planted in high heat in the middle of summer need more than you might imagine - at least 5 gallons per inch of trunk diameter per week. And this should be after the initial planting, wherein both the rootball AND the planting hole have been thoroughly soaked. This practice should continue throughout both the first and second growing seasons in the ground. I suspect the trees are under drought stress......just not getting enough water. The symptoms you describe certainly fit this diagnosis. Either the original rootball has been allowed to dry out or was not properly hydrated before planting or the trees are not getting enough supplemental irrigation this season. Dig down into the rootball and check - the soil should be just moist to the touch and that moist area should extend all the way down to the base of the rootball, a good 12-18". The deeper the soil moisture extends, the more likely and easier the tree roots will follow and a good, deep root system results in greater drought tolerance after establishment. Mulching properly will also help to conserve soil moisture. 4) Finally, when a plant is under stress, you never want to fertilize it. The roots are unable to metabolize it adequately and it just increases the stress. Trees generally require minimal fertilization anyway - only if the soil tests deficient in particular nutrients or if the appearance of the tree itself indicates a specific nutrient lack, i.e. chlorosis. MiracleGro would not be my first choice.....a slow release granular fert applied throughout the dripline would be better but test your soil first before applying any fertilizer. Fertilizing when not needed is often worse than not fertilizing at all. FWIW, 1.5-2.5 inch caliper trees can hardly be called seedlings :-) Water appropriately for their size and your climate!!

I love your sweep of lawn bordered by the perennial bed and the pin oak is just beautiful! As others pointed out, it won't remain in scale with your home and yard ultimately, though- it seems like every tree grows to about twice its normal size here. And another large tree or two will have your home buried in gloom in time. I am no expert so others may nix this idea, but why not plant a nice dark green hedge along the boundary, arborvitaes maybe? And then in front of that, one or two japanese maples with good color that will show up against the green hedge? Many of them get beautiful fall color (I was originally from new England, myself, and I miss the beautiful autumn, too!) and then the bare branch pattern would be pretty in front of a hedge in winter as well. That would give you privacy and still let some sun shine in (when it is out, lol). You could fill out beneath them with shrubs and perennials.

Other than knowing that sugar maples are salt-sensitive, I don't have any advice for you. Our climates are just too different and sugar maples are not a common species in my area. As this forum tends to gather the most activity on topics relating to Asian maples, you may find better feedback for your question on a more regional forum, where these trees are more commonplace - New England Gardening?