Robinia 'PURPLE ROBE' black locust
size/type
medium-sized tree,medium-sized tree
usual height
5-8m
usual width
2-4m
leaves
deciduous broadleaf
colour of leaves
flowers
showy
colour of flowers
blooming time
May-June
location
full sun
USDA zone (lowest)
4 (down to -34°C)
winter protection
for zone 5+6
for zone 7
categorized
Flowering trees always bring something extra to every garden. This locust confirms the fact. It is a controlled hybrid between robinia hispida var.kelsey and robinia pseudoacacia. One gave large size of flowers, the other added rich colour. It was patented in 1961 and is possibly a thornless mutation of an older variety Casque Rouge.
Description of the plant:
Purple Robe locust makes profusion of 15-20 long racemes of pea-like, deep pink to fuchsia-purple flowers in mid spring. They come out from mid May and continue for about three weeks. You can make the tree flower once again in mid summer by pruning it right after the first flowering in early summer. Locust blooms on new wood, too, so you will be able to enjoy its bright pink flowers again on hot summer days.Pinnate leaves are mid green and continue emerging until autumn. Thanks to its new leaves the plant keeps its fresh looks all season long. The crown is pyramidal, quite regular in shape and light, providing enough filtered sunlight for plants living underneath. The tree seldom exceeds height of 8 meters. Branches are almost thornless.
Locust needs super-well-drained or dry soil, preferably poor. In wet or boggy soil it will most certainly die. Staking the trunk of a freshly planted tree is necessary for minimum of three years. Annual pruning reduces risk of wind damage. Fully hardy to min. -34°C, possibly more (USDA 4).
Last update 27-05-2018
WANT TO TRY A SIMILAR PLANT?
