Can a Wax Myrtle or a Muskogee Crape Myrtle tree grow well in southern Massachusetts which is zone 7a (very close to zone 6b)?
Yes, though you could have die back perennials some years.
have you seen them in the area???
thats usually the easy answer ..
and the second.. is whether they are sold in good nurseries ... usually.. they dont sell... what isnt going to live ...
of course.. zone pushing is always a mail order option ... but they make a lot of claims.. that may or may not be true...
and then finally.. a winter .. like the last one rolls thru.. and they die ...
Ask in the New England forum. There are people who grow various crape myrtles in the warmer, coastal parts of New England.
You can start by reading this thread.
Here is a link that might be useful: Crape myrtle thread in New England Forum
Thank you mad_gallica. That forum post was very informative and makes me feel better about buying a Muskogee Crape myrtle, since I am in Coastal MA and people on that forum are saying Coastal MA should be fine for Crape Myrtles.
Still not sure about the Wax Myrtle though, all of the forums seem to only be about Crape Myrtles.
There are two different species of Wax Myrtle (Northern Wax Myrtle and Southern Wax Myrtle). The Northern is semi-evergreen to deciduous; Southern one is deciduous. Northern one would probably is a better choice for you. Regarding the Crape Myrtles, many are fine to zone 6b/7a. Most all of mine survived...even after the Winter from he// (deep snow probably helped with that btw). The thing is, you need to consider heat requirements (as well as cold minimums). If a zone does not experience enough Summer heat, the wood may not properly ripen. So ironically, there are many semi-tropicals that will grow robustly in the Mid-Atlantic zone 7ish climates that do less well in Pacific NW (Zone 8+ climates). Crapes have a relatively high, Summer heat requirement. It's July, see any in bloom around you. Finally, you specifically wanted a 'tree'. Crape may be a viable option for you as a shrub (with some degree if annual dieback), but not sure if a tree is possible. Give it a try and good luck!