
			Missouri Landscape & Nursery Association/MLNA 6209 Mid Rivers Mall Drive, Suite 128 St. Charles, MO 63304 (636) 939-9079

Plants of Concern List

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How sad to lose this beautiful choice for fall color!

Fraxinus pennsylvanica

Common Name: green ash

Zone: 3 to 9

Plant Type: Tree

Family: Oleaceae

Missouri Native: Yes

Native Range: Eastern North America

Height: 50 to 70 feet

Spread: 35 to 50 feet

Bloom Time: April - May

Bloom Color: Purple

Sun: Full sun

Water: Medium

Maintenance: Medium

Easily grown in average, medium,
well-drained soils in full sun, this distant cousin of the olive has more than
65 members in its family. Many types of Ashes are found throughout North
America. All ashes have opposite compound leaves and very stout twigs.
Depending on type, they vary from small, rather slender specimens to very large
deciduous trees.

Like maples, ashes have winged seeds called samaras. The
wood of the ash, used to make sports equipment is prized for its suppleness and
flexibility. It is used for tool handles and in the manufacture of furniture.
Due to the arrival of Emerald Ash Bore which is typically fatal to these trees,
restrictions and quarantines are in place in several states. Although the
Emerald Ash Bore has not been found in Missouri yet,the treat of its has
triggered a decline in the recommendation of Ash Trees for any purpose.

Green ash has the largest growing range of any of the native ashes, extending
from Nova Scotia to Alberta south to Florida and Texas. This is a lowland
species that is commonly found throughout the State of Missouri in low woods,
floodplains and along streams, ponds and sloughs (Steyermark). It is a medium
sized tree, typically growing 50-70' tall. Young trees are pyramidal in shape,
gradually maturing to a more rounded but usually irregular crown. Green ash is
similar in appearance to white ash. Foliage turns yellow in fall, with the
quality of the fall color often varying considerably from year to year.
Gray-brown bark develops distinctive diamond-shaped ridging on mature trees. As
with white ash, the wood of green ash is commercially used for a variety of
products including tool handles, oars, garden furniture and sports equipment.

Emeral Ash Bore as well as other bores and Oyster shell scale are serious
insect problems. Leaf miners and ash sawflies may also occur in some areas.
Potential diseases include fungal leaf spot and canker. Brittle branches are
susceptible to damage from high winds and snow/ice.

Emerald Ash Borer

Emerald ash borer (EAB), Agrilus planipennis Fairmaire, is an exotic
beetle that was discovered in southeastern Michigan near Detroit in the summer
of 2002. The adult beetles nibble on ash foliage but cause little damage. The
larvae (the immature stage) feed on the inner bark of ash trees, disrupting the
tree's ability to transport water and nutrients. Emerald ash borer probably
arrived in the United States on solid wood packing material carried in cargo
ships or airplanes originating in its native Asia. Emerald ash borer is also
established in Windsor, Ontario, was found in Ohio in 2003, northern Indiana in
2004, northern Illinois in 2006 and eastern Pennsylvania in 2007. Since its
discovery, EAB has:

With our global economy and the free movement of nursery stock around the US,
there is an ever-increasing list of "exotic" insect pests that we should be
aware of. However, given our busy schedules and the seemingly steady stream of
alerts in the press or in gardening publications, it is easy to become
desensitized. We cringe a little less every time we read about Asian Longhorn
Beetle killing thousands of trees in Chicago or Gypsy Moth moving ever closer.
Until a pest, such as Japanese Beetle appears on our doorstep, we are not forced
to develop a strategy to deal with it. Emerald Ash Borer, a pest recently
discovered to be a serious problem in the Detroit area, is an insect that stands
a good chance of changing the face of the nursery industry in Missouri over the
next 10 years. We should do what we can to keep this pest out of Missouri for as
long as possible.

Emerald Ash Borer (EAB) should be considered a serious threat to Missouri
landscapes and forests for several reasons. First, while it was only first
identified in the U.S. in July 2002, it is estimated that, during the previous
five years, EAB had killed millions of ash trees in forests and landscapes in
Michigan and Ontario. Second, the insect is thought to attack trees of all
species of ash, including apparently healthy trees. In China, where the insect
is indigenous, ash trees typically die within two or three years of infestation.
Third, ash trees make up a major portion of trees used in Missouri landscapes,
but also a significant component of our forests. Interestingly, EAB is a
Buprestid beetle in the same genus (Argilus) as Bronze Birch Borer, which
has essentially eliminated the use of European white birch and several other
birch species in Missouri landscapes. EAB is of even more concern because we
have millions of ash trees in our forests that can serve to spread an
infestation if it were to get started here. The pest was recently discovered
near Toledo, Ohio, the infestation probably arising from insects harbored in the
wood of shipping crates from China. It is not difficult to imagine a similar
scenario in St. Louis. Also, since infestation with EAB is not easily detected
during the early stages, it is highly likely that shipments of nursery stock
from infested, but not-yet-quarantined areas, will serve to spread the insect to
new regions.