To repeat what has been said a number of times before, there are Red Maples (Acer rubrum) in varying cultivars and then there are other cultivars of maples whose leaves turn red in the fall. There are also maples, mostly Japanese maples but other species as well, whose leaves come in red or reddish, some of whose leaves stay red and some turn green. The TRUE Red Maple is the A. rubrum, so called, as far as I know, because the flowers, which are very early before the leaves, are very red, as are the early stages of the samaras. Any other tree, if of another variety of maple (Norway, silver, etc.) MAY have the word red somewhere in its name, or have red leaves all summer or in the fall, but it will NOT BE a Red Maple, although it may be a red-colored maple, for example, the above mentioned Crimson King Norway Maple. Sorry for the lecture, but it's a pet peeve, and so you got the rant....

I don't know about compatibility but it shouldn't be hard to find sugar maple seedlings. Look for forestry seedlings from state government run forestry departments. Now is the season to get them. Unfortunately, now is not the time to graft them. Wait until they are dormant again. During spring the rootstock will be growing actively and sap could flood and kill the graft union. summer grafting is possible but more difficult, That will give you a season to pot up and grow your new seedlings a little. And try as many seeds as you can get. They will not be clones, but still come from this seemingly sentimental specimen. If you grow enough you will find one you like, maybe better than the parent.

It looks like some varieties of red maple might work well. There appear to be varieties that are perfectly happy in florida, which have no chill requirements to break dormancy. Sugar maples, however probably wouldn't do particularly well. One article I found states that they require 2500 continuous hours of chill (below 41f) to break dormancy. Without that chill, they'd probably do well enough for a couple years, but eventually would either go dormant and not come out of it, or they'd just die from the stress of not being able to rest. Here is a link that might be useful: Top of page 3 references the lack of chill requirement for floridian acer rubrum

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!!