Answer: Thank you for asking. The mimosa cultivar "Summer Chocolate" is not included in the current online Monrovia plant catalog. This cultivar was recently introduced by Hines Nursery. Here is a typical report: (you may need to cut and paste the complete url into your browser ot make it work correctly)
The selection is especially notable for its deep and lasting foliage coloring as indicated by the variety name.
Mimosa or Albizia julibrissin is subject to a fairly wide variety of potential pests and mimosa wilt or fusarium wilt is also a possibility although it is more common in the southern part of the country. (Even if a specific variety is considered resistant to a disease, that does not mean it is immune.)
It does seed about, although seeding seems to be less of a problem in northern climates. Extreme cold during the winter can cause dieback or in some cases can kill the tree outright. In your winter hardiness zone of 5A -- the coldest part of zone 5 and possibly as cold as zone 4 depending on your microclimate -- I would be concerned about losing this tree during the winter. Mimosa trees are generally considered hardy in zones 6 through 9 and your climate is considerably colder than that range. If you plant it, try to locate it where it will have protection from winter wind and in a sheltered microclimate.
Your local county extension should be able to tell you if invasiveness is a problem in your local area, and whether or not the disease issues are of particular concern in your local area. I hope this helps.
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