The invasive Robinia

 

When I took over this garden there were four robinia trees.  I have removed two of them but if I am not vigilant I could soon have a robinia forest, even under the house.  The robinia is a suckering plant and according to some gardening advice damaged roots can cause suckers to shoot.  I have found a couple of robinia suckers under the house, and from under the pile of firewood where I doubt if there has been any disturbance to the invasive root of the surviving trees.  My back neighbour also has a robinia and I suspect that specimen is feasting from beneath my compost bin.  The two robinias left (a white and pink), are on either side of the entrance to the driveway.  They are beautiful trees, even when they look a bit unkempt from being muched on at the top, by resident possums.  Robinia shoots appear in the garden beds and on the nature strips where the mowing keep them down.  I cannot use roundups unless I want to kill the mature trees as well, but they so beautiful to look at when in bloom.  The pink robinia in the front I had to chop down to make way for the apricot.  It was impossible for me to remove the deep roots so I do get suckers from that spot, which are cut down the moment they appear.  The other robinia, the golden variety, had to be moved to make way for the garden boxes.  It was a very attractive tree, with golden leaves and white pea type flowers.  A friend agreed to take it to her property and I pruned it after gathering the slightly scented flowers for the house.  I dug as deep as I could, cutting the roots,  and for a couple of weeks before it was picked up, watered it daily.  The plant survived the move but the following hot summer killed it.  See picture of the plant after the pruning, with the landscape gardeners working around it.  Perhaps it was a good thing it did not survive.  I hate to think a robinia forest taking over my friend's 20 acre property.

  

On the two mornings when watering is allowed I keep a lookout for the robinia suckers.  Their pinnate leaves are easy to detect.  I may take the advice of a TV gardening show where unwanted suckers are removed and then boiling water poured on to the spot to kill the underground roots.