By Ellen Barcel
Last week’s article focused on a late summer flowering tree, Styphnolobium japonica, the Japanese pagoda, which is a member of the pea family. Another tree that blooms in mid-August is the mimosa (Albizia julibrissin), which has fragrant pink (some varieties are orange) fluffy flowers. Mimosas are also in the pea family, but the flowers are very different from the Japanese pagoda tree.
The problem with this tree is that it is very prone to a fungal disease. Somewhere in the 1960s or ’70s many gardeners planted the quick growing and beautiful tree. Then the disease struck, killing thousands of trees on Long Island.
The mimosa, also known as the silk tree, is prone to the fusarium wilt. It is spread by contaminated soil, the pathogen being taken up by the tree roots, which means that if you have a mimosa that died as a result of this disease, don’t plant another one in the same area. I lost three massive mimosas to this disease way back when. This is a reseeder, so many new little trees would sprout, but then in a few years die. So I began pulling out the seedlings before they became established.
Bartlett Tree Research Laboratories notes that once a tree is infected there is no cure. When removing a dead mimosa, do not chip the wood and use it as a mulch because you would then be spreading the disease. There are several disease-resistant (not immune) cultivars, ‘Charlotte’ and ‘Tryon.’
In addition to the sweetly scented flowers, the tree produces a light shade, even as a mature specimen, so it is a great tree to add to your garden. Just remember to get one of the disease-resistant cultivars.
Ellen Barcel is a freelance writer and master gardener. Send your gardening questions to email@example.com.To reach Cornell Cooperative Extension and its Master Gardener program, call 631-727-7850.