Garden Column for the Salisbury Post
Darrell Blackwelder
July 6, 2002
	While growing up in upper state South Carolina, our family could always depend
on a large mimosa tree to have a burst of pink colors during the heat of summer.
Mimosa trees are known for their interesting blooms.
Being a true legume, mimosa trees (Albizia julibrissin) grow very fast,
producing bean-like pods similar to those on redbud trees.  The fern-like leaves
are light and interesting, but fail to produce fall color. Mimosas are small
trees usually growing no more than 25 feet found growing almost anywhere, from
abandoned parking lots to roadside embankments. Mimosas like do best in hot
weather.
 	Unfortunately, it’s a tree that has a very short life span.  The tree is
subject to a vascular disease commonly referred to as mimosa wilt. This disease
has practically eradicated mimosa from many areas the South.  Ironically, the
disease was first discovered in North Carolina in 1935.
The classical symptoms are wilting and yellowing of the foliage. In some cases
the leaves will become dry and shriveled while remaining green or yellowish for
some time. Later the leaves fall, and the branch dies. Usually the tree is
affected branch by branch and will be completely killed within a year of the
onset of symptoms. It’s rare for a tree to live more than 20 years, a mere
infant in a trees’ life.
	Another common characteristic of the disease is brown discoloration in the
sapwood, especially the outermost annual ring, caused by gum-filled tissue
cells. This hinders or completely inhibits water movement from the roots to the
aerial portion of the tree. This discoloration can be found in trunks and
branches even before the leaves wilt. During the summer months it is not
uncommon for the bark of infected trees to rupture and exude fermented, frothy
sap readily attracting insects.
	The fungus lives in the soil and enters the tree through the roots. Dead and
dying trees should be cut down and destroyed to avoid the spread of the disease.
Once the disease becomes established in the soil in an area, there is little
that can be done to save nearby trees. Also, the fungus may be transmitted in
seeds collected from diseased trees.
 	There is no known control for this disease. However, there is renewed hope for
mimosas for the landscape. Plant breeders have developed two resistant types of
mimosa that are virtually immune to the wilt. Cultivars, Tryon and Charlotte,
the former having light-colored flowers, and the latter, deeper red ones can be
found with some persistent investigation. They may be difficult to locate but
well worth the effort.