When a large old climbing hydrangea is removed from a wall, it will leave
the wall severely stained & in need of sanding & repainting. It will cling
so well to cedar shingles that a few shingles are bound to come loose when
the vines are pulled free. But the little tiny hair-roots do not penetrate
surfaces, nor run under shingles, nor cause structural damage to masonry.
It loves to climb the bark of large trees, & causes no harm to trees.
It's basicly harmless.

The same can be said of Schizophragma hydrangeoides, which can likewise
cover an entire large wall. In winter, climbing hydrangea's orange hairy
limbs are more beautiful than Schizophragma's dark twigs, but in most
other regards, Schizophragma is a nicer large vine. Its leaves are
prettier & more delicate looking, with the variety called "Moonlight"
having veined pewter leaves of great beauty. The flowers are large bright
lacecaps whereas the common climbing hydrangea has a cluster of small
green flowers circled by larger sterile white petals & only half as showy.
Both have good autumn leaf colors.

Hydrangea anamolis can become a very thick wall shrub hanging far from a
wall, whereas Schizophragma to large extent clings closer against a wall.
Schizophragma establishes more quickly than does Hydrangea anamolis,
although neither establish swiftly; with small starts of either, much
patience is required to see them start doing much. The hydrangea is
perhaps overly common in some areas, whereas Schizophragma is not over
utilized, plus it has more varieties to select from, though none are so
easy to find as H. anomolis. A big healthy start of H. anamolis is fairly
cheap, but if you can find a large S. hydrangeoides, it'll be expensive.

If I could have only one or the other it would be the Schizophragma, but
I'm happy to have both.

-paghat the ratgirl

--
"Of what are you afraid, my child?" inquired the kindly teacher.
"Oh, sir! The flowers, they are wild," replied the timid creature.
-from Peter Newell's "Wild Flowers"
See the Garden of Paghat the Ratgirl: http://www.paghat.com/