The snowdrop-like flowers and smaller-statured head are what bring Jack tree into the limelight.
Jack tree is certainly an uncommon small tree. Have you ever seen it before? We'd like to see more of it in gardens and landscapes because it is a tough and beautiful addition to the vast line-up of trees that thrive in the Southeast (our clay and climate may be tough, but our plant pallet is awesome!). I live in the Southeast, so my thoughts are geo-centric to this region, but it's cold hardy down to zone 6a.
It's not too picky about soils, but it must have an acid pH and be watered regularly until its roots penetrate the surrounding soil. After the delicate establishment period, we've found it to be quite drought AND heat tolerant in Zone 8a. We read it's heat tolerant down to zone 10b, but have not directly seen that for ourselves. We'd love to know about more about heat tolerance, so send or post a note.
Jack tree is a member of the Styracacea family. That means Sinojackia rehderiana is related to Styrax and Halesia trees. If you know those trees, you can envision this tree covered in similar-but-different flowers. The pictures show these flowers and how they appear at the same time the leaves are coming out (the floral display is by no means diminished by this trait).
Have you noticed how 1-2 year old stems on Halesia have a fine layer of outer bark that peels of in threads? Sinojackia does that too! It's lovely.
Fall color is usually a bright yellow. I say usually because the yellow was gorgeous in 2017, but in 2018 it was "meh" for Jack tree and most plants in our area.
We have 1 multi-trunked tree remaining for 2020, but will have more multis and single trunks in 2021.