My guess is Verticillium Wilt. Research that and see what you think. It is a soil based fungal disease that is common in your (our) area and hits Sugar Maples pretty hard. One tell tale clue is to cut through a section of the dead or dying branch and look for a greenish brown stain or streaking in the sapwood. To be absolutely sure, contact your local extension office and send them whatever sample they would need to run a test to confirm. Sorry to hear about this as unfortunately, there is really no cure for this malady. - Brad

.... agree with Pam - a cultural issue. Likely over-watering due to excessive water-retention and irrigating too frequently. How have you been fertilizing, and with what? There really isn't enough info to offer specific advice, but sinking your container at least half-way into the soil in a semi-shady spot and watering/fertilizing regularly would probably be a good strategy while you figure out how you can manage to provide a soil that allows you to water at will w/o having to worry about root rot or suppression of root function due to excessive water retention (at repotting time next spring). Once you get your plants in an appropriate soil and start a good fertilizer program, everything gets easier. Keep in mind that if you're going to maintain your trees in containers over the long term, tight roots ARE going to limit your plant unless you learn how to deal with the issue on a regular basis. Potting up doesn't/can't provide a solution to tight roots; it only slightly eases the limitation imposed by the condition. Something for you to read, if you like. Al

Interesting, the publication by Wright also shows hybrids with Acer platanoides (Norway maple) and Acer negundo (Boxelder maple), as well as Acer saccharinum (Silver maple) and Acer negundo (Boxelder maple). It would be interesting to see such a study replicated, and for a full growth cycle for the hybrids to take place. I live in Utah, and the native Acer grandidentatum (Bigtooth maple, close sugar maple relative) flowers at the same time as the invasive non-native Norway maple in our foothills at about 4,500 ft. Sometimes bees cross-polinate them, I'm sure of it when both trees grow near. Bees still prefer the Norway maple for its showy and nectar rich flowers. Both insects and wind pollinate them, but mostly wind because sometimes it is too cold for bees to work. I have grown some potential hybrids between the Norway and Bigtooth maple, from a Bigtooth maple 'female' tree, and the seedlings were weak, waxy/glossy, and lime green possibly from iron chlorosis. None of those made it after a week...

Manor View Farm in Balto Co, has sugar maple in their inventory. You will have to have your contractor place the order and pick them up. Someone like Stadler Nursery should have them (many locations) Waverly Farm nr Frederick -wholesale- We live in Northern Maryland, right on the PA line...... well that narrows it down to about 240 miles, so I will assume you are in the eastern part where I am. If you want to try the retail route consider: Valley View Farm, Sun Nursery, Homestead Gardens, in MD Merrifield's or Betty's Azalea Ranch in Fairfax Co, its a matter of calling around and shopping around, ask when they get their fall shipments in. Below is an interesting cover from our state's promotional literature. The sugar maples are a cultivar because they are all so uniform. I can't say which one, maybe 'Green Mountain' Location is Buckeystown Pike south of Frederick.