"Anne Chambers" wrote in message
...
I have a pink Robinia (Robinia pseudo.decaisneana) tree, planted as a
seedling bought from a nursery about 10 years ago. Four years ago, a
smaller plant appeared about 2 m from the original tree (I'm not sure if it
was a seedling or a sucker from the original) and I let it grow.

'Junior' has flowered for the first time this year (it's now about 1.5 m
high, the original is about 5m) but the flowers are fragrant white,
whereas the original tree's flowers are a deep fragrant pink. Is this
usual ?


--
Anne Chambers
South Australia

anne dot chambers at bigpond dot com

Robinia's are serial pests in the plant world. Here (WA) people plant the
mop top robinia and all is well until they dig and cut one of the roots. A
sucker comes up from the root and it is different to the mop top because it
is the rootstock. The reason is they graft onto true Robinia pseudoacacia
rootstock and graft a wanted scion ontop, in your case decaisneana, to form
a standard or nice flowering tree. The rootstock is very hardy and supports
grafts well. But when you cut the roots it will send up a sucker. This
happens because the roots have dormant buds along their length. Any cut will
induce a dormant bud to shoot but it will be of the rootstock not the
desired variety.

I have seen thickets come up in vegetable patches 35 metres away from the
parent tree. They seem to be shallow rooted so makes it more probable a new
tree will come up. if you want to remove this tree you have to remove all
the roots as well and it may take many years to stop the suckers coming up.
Your neighbours may enjoy the ride too. This web link may help
http://www.au.gardenweb.com/forums/l...083220597.html