Take samples into your local extension office for diagnosis. Sounds like bud miners, which can be a problem for sugar maples, but impossible to confirm only by description. The extension office will provide recommendations for treatment as well, if that is the problem.

Agreed^. If you can provide more historical context, we may be able to help. Ie, any herbicide treatments, especially those containing dicamaba, or Imprelis-brand herbicide, a known tree killer? Those factors Ken mentioned? Something's amiss here. I don't think I could kill a silver maple if I tried. Well,okay, I could, but it would not be easy. And did the tree show gradual decline, or all of a sudden? BTW, I'm not at all hating on this tree species, but honestly, around here, in the early summer, peeps that don't keep their house gutters clean have veritable nurseries of silver maple seedlings coming up in these gutters, by the thousands. A supremely easy tree to come by and to get to grow. I sure wouldn't spend an $$ on one. And depending on the situation, a thirty or forty foot tree is not at all hard to drop, provided there are no targets in the way. when I moved into the house I continue to reside at, in 1981, we not only had our city's largest silver maple in the backyard, there was also a young one of perhaps 14 inch trunk diameter, planted in our tiny front yard, and leaning back at our little house! This tree did not live much longer after that then it took me to start my power saw. By now, it would have become an enormous liability, and that's coming from me-a guy who tolerates much tree hanging over his and other houses. That one was ridiculous. +om

Good to hear the Larch are making a run anyways. Have the Abies or cryptomeria set resting buds? Or are they just taking their time deciding if they want to grow? Too bad with that silver maple next door. Have you dug down in that first planting site? Did you find maple roots encroaching into that area? You might be surprised to find no roots that far out being it's a clay soil but you'd have to check to find out. Not sure about that other site with the gravel. That shouldn't bother the roots by any means except that gravel areas are generally drier due to the moisture perking faster. It might be hard packed from cars and trucks parking in that area. I really can't say from here. Did it seem hard to dig there?

I only have so much mental energy available for Houzz/GW and in this case, I will address recommended trees, but sometimes I just don't have time...also, recommendation is increasingly fraught with the nature of climate change and ecological uncertainty, like new and emergent pests. My garden is full of the damn lantern flies right now. I have no idea what they could be damaging. More important, really, is that you get a tree that was well grown and plant it correctly. So...one that doesn't have a huge knot in the root system that will cause a failure 5-10 years in the future. And that was freshly dug when you bought it, not sitting in a container for years. If you get a smaller one...that you know how to fix tangling roots. Until Houzz has a better way of me tagging/locating my older posts about this, sorry, I just gotta say, "google it". But here is an axiom I'm happy to stand behind: MOST NURSERY STOCK IN THE US IS POORLY GROWN. As Anna points out, the ROI on investing in a large tree, diminishes the larger you get. But if there is one nursery in the DC area for _large_ trees, I can recommend, it is this one: http://www.raemelton.com/ They know their stuff. Whatever you buy there, they custom dug with the proper equipment. As for starting with smaller trees, I wouldn't know where to begin...plant collectors like me do a lot of mail order, and one of the mail order places I would have recommended, Oikos, just closed. The reason I would have recommended it is they used to sell an Oak called Quercus X procera that is very fast growing, but forms a sturdy, single trunked tree naturally. Other trees I might recommend off the top of my head, for (reasonably fast) shade: thornless honeylocust Ulmus 'Allee/Emer II' (I guess all the new American elms being sold by Raemelton are considered disease resistant, so those as well) seedless ginkgo Lindens bald cypress Cedrus atlantica or hardy cultivars of C. deodara oops - just realized these next 2 might be too messy for you. Are there puff-ball free sycamores? Norway spruce (kind of disappointed Raemelton sells blue spruce, but with the market still inexplicably demanding those dogs, I guess they have no choice) MAYBE planetree - they are potentially huge and you would certainly only plant 1 if that were your choice Just noticed sam hawking a native plant sale this weekend in Alexandria on another forum. I'm all for natives if they fit the bill. Someone there might have small bald cypress trees, for example. https://www.houzz.com/discussions/6173885/upcoming-plant-sales-events-at-botanical-gardens-and-museums#n=1