My condo has a rooftop garden on the 6th floor. We do the gardening ourselves. We are thinking about planting a Redbud in one of beds, for its colour. Is this a good idea? Our planters are large beds about two feet deep sitting on top of the roof membrane. We are already growing Serviceberry, Japanese Maple, Cedars and Boxwood. My concern is the root system and ultimate height of the Redbud .. or does the tree accomodate to the space it has?
Your garden sounds like a wonderful place. Eastern Redbud (Cersis canadensis) can be grown in a container and would be a lovely addition to your rooftop garden but you would want to purchase a dwarf variety that would grow to a maximum height of 12 feet, rather than the regular variety that could top out at 20-30 feet. The 2 feet of soil available would not be sufficient for the larger varieties. There are several dwarf varieties available at reputable nurseries. Rooftop gardens can be very sunny and windy places though, often causing planters to dry out quickly. Container grown Redbud need frequent watering and fertilizing for the tree to do well. Adding mulch to the bed would also assist in retaining moisture and protect the soil from the wind. Finally regular pruning would help you control the size and the shape of the tree.
Here is some general information on the Eastern Redbud.
I hope that your garden and your new Redbud provides much joy to you and your neighbours for years to come.