My strata council has decided to remove the beautiful Katsura (Cercidiphyllum japonicum) trees from the property for fear that the roots may be invasive and damage the membrane underneath the planters. The trees are situated over the parking garage, were planted some eight years ago and are perhaps 30 feet tall. Can you tell me if the strata council's fears are legitimate with regards to the potential for the roots of these trees to cause damage? They are gorgeous trees and I will be very sorry to see them cut down.
Katsuras don't normally develop too much of their root mass on the surface, however I have seen then planted in hard ground where they had no option and they end up with a grounbd level root system that creeps all over the place. You can see this sort of thing at the Rhododendron Species Foundation in Federal Way. If your trees have insufficient depth of soil for roots to go down, as may be the case as you say they are planted on top of a parking garage, the strata council may have cause for concern.
you could consider having an air tool root (air spade, air knife) excavation to determine possible problems or root growth patterns. Root growth in containers (even large planters) can be very different from the habit in open ground. what it the diameter of the trunk? if its over 30cm at a couple feet from ground level you may have to talk to city of vancouver about a removal permit and this is normally only issued to hazard (imminently dangerous to people and/or property) trees and sometimes to development permits.
Hello Brian, Katsura trees can grow to 45 m. There a couple of dwarfs, but 1.5 m seems really small. Where did you see that? As far as where to buy one - we do have a sourcing plants forum, but it is for members only. We prefer to keep discussion of commercial sources and individual transactions off the public area. If you would like to take a moment to join - it's free and simple - you can post your request in that forum. In general katsura trees are not difficult to find, but the dwarf you refer to may be.
"Too thirsty --and if it gets the water it desires it grows awkwardly gigantic. In its native China and Japan, there is ample summer rainfall. In Seattle our dry summers hurt this lovely tree, causing fall color in August. But if we do water it, most of us have too little room for its great size. Specimens some 60 to 70 years old can be nearly 100 feet tall; it is often nearly as wide as tall. So it is ideal only if you have a large, irrigated garden. But planting it in an unirrigated parking strip is a mistake." http://www.arthurleej.com/a-overplanted.html
OK Brian, That is a completely different tree. That is a maple (Acer) cultivar named 'Katsura'. The tree being discussed in this thread is the katsura (Cercidiphyllum).
Obviously, I'm joining in this very old discussion at a much later date, but felt this is still pertinent information. I am in the midst of redesigning an entrance drive and clubhouse planting at a high-end condominium complex in Portland that is around 15-18 years old, specifically because of the Katsura Tree Roots. Attached are pictures showing what a problem the roots can be. Give them lots of room.
