| You will find heaps of postings on this site about robinias and their bad suckering habits. I planted one quite close to a brick retaining wall bordering a paved area. It is now about 4 metres high and I have never had a sucker and, so far, no problems with roots. I think the suckering has something to do with soil type. Mine is heavy clay with lots of organic material incorporated into it. The tree is growing in a shrubbery and the soil is dug over on an annual basis and mulched with leaves. The robinia is on the northern side of a courtyard and casts a lovely dappled shade in summer. | 
