Why worry about your elm?
What is your elm tree worth?
What is Dutch Elm Disease?
Tree Care Made Easy - Watering, Fertilizing, Pruning
Pruners and other Resources
worry about your elm?
Dutch Elm Disease can infect
types of elms in Saskatchewan. American, Siberian &
elms are all susceptible and must be treated equally. American elms are
most common shade tree found in the older neighbourhoods of
In fact, there are as many as 100,000 in the city. American elms
native to Saskatchewan and therefore ideally suited to our cold, harsh
They can live for 250 years or more in our urban setting, providing
and shade for generations to come.
American elms have a
“umbrella” shape when seen in profile, growing to 23 metres (75 feet)
urban conditions. The canopy of mature trees will often
across a street creating an attractive “tunnel” of branches
leaves. Its dark green leaves are oval in shape and asymmetrical
halves that are not even in size and shape) at the base. The leaf edges
Leaf of an
||Leaf of a Siberian Elm
Siberian elms (often
Manchurian elms) are less graceful and majestic than the American
A hardy, weedy, and relatively short lived species, the Siberian elm
have a variety of forms depending on location and pruning – from a
hedge to a single tree. Their leaves are similar to, but smaller
those of the American elm. Siberian elms are fast growing, typically
heights of 12 m (40 ft). They are unpopular with gardeners as
produce an abundance of seed and their branches break easily.
are less likely to die from DED, but can be a source of infection.
elm tree worth?
In terms of Real Estate it
estimated that a mature American elm is worth at least $3,600.
doesn’t even begin to take into account the many other benefits of
such as shade and wind protection, as well as the beauty and clean air
Properly planted trees can
air-conditioning and heating bills by 10-15 percent. Studies have
that a mature urban forest increases property values by 5-20 percent,
residents’ health and well-being, and can even reduce crime
If you’re a nature lover, consider the habitat that trees provide for
and other animals. There are a multitude of reasons to save
urban forest. It costs as much as $1000 to remove a tree and as
as $250 to prune it. Why not keep your tree healthy and alive for
and your grandchildren to enjoy – it makes good financial sense.
Dutch Elm Disease (DED) is a
fungal disease that can kill an American elm in as few as three
It is spread by the native elm bark beetle that feeds and breeds in elm
Elm bark beetles are tiny, about the size of a pinhead, and can be
without you noticing them. The disease is spread as beetles that are
with the sticky DED spores move from tree to tree. Control the
and you can control DED!
DED was first identified
the Netherlands and northern France in 1919. It was actually
to Europe from the Dutch East Indies during the late 19th century.
The first infections in
America were observed in the United States in Ohio in 1930. In
the disease was first reported in Quebec in 1944. Since
DED has spread to almost everywhere that elms grow.
The first reported case of
in Saskatchewan occurred in Regina in 1981. While the situation
is under control for now due to a very effective DED program,
areas of the province have not been as lucky. Manitoba has had
since 1975. The disease spread rapidly from there into eastern
in the 1990s. This spread has largely occurred along natural
of wild elms, such as the Souris River Valley.
Unfortunately, DED can
very quickly. All it takes is someone transporting infested elm
to a disease-free zone. This is likely what happened when DED was
in Davidson in 1999. DED is now within an hour’s drive of
DED is almost here and
young and old, must be ready to lend a helping hand. Are you
to join the fight to save our elms? With your help we can win the
and we will have elms to enjoy for years to come!
DED causes elms to shut down
water-conducting vessels so one of the first signs of the disease will
a branch in the upper canopy of an elm with leaves that wilt, turn
and shrivel in early summer. They often remain on the tree for
full season. If the disease strikes later in the summer, leaves
usually wilt, turn yellow and fall prematurely.
If you see an elm with the
of DED call the City of Saskatoon at 975-3300. The Pest Control
will take samples of the suspicious branches and send them away for
If the sample is positive for DED, the tree will be removed and buried
a designated area of the landfill. The quicker this happens the
Elms that are located
city property, e.g. on boulevards and in parks, are maintained by
employees. However, privately owned trees are the responsibility
the landowner. It is up to you to make sure your elms are
for environmental and legal reasons as you are liable for any injuries
damages caused by fallen branches or dead trees.
This is what you should
- Don’t store or transport elm firewood as
bark beetles will breed in it. It is illegal! One two foot
of elm wood can hold 1,800 infested beetles. Elm firewood must be
to the city landfill where it will be buried to make it inaccessible
- Hire a professional to
the dead or broken branches from your elm trees to get rid of elm bark
breeding sites. Do not prune during the
ban (April 1st – August 31st) when the smell from cut branches
attract elm bark beetles.
- Band your trees for canker worms
every fall when the cankerworm population is high. This will not prevent DED,
but will keep your trees healthier and less likely to contract the disease.
Also, make sure to renew the sticky layer in the Spring if needed and remember
to take down your bands by May 15th.
- Watch for the symptoms
DED and report any suspicious looking trees.
Many people carefully water,
and cut their lawns, but never give a second thought to their
Proper tree care is not much different. Trees also need watering,
and a good pruning every now and then!
Elms are fairly resistant to drought, however if you notice that leaves
starting to droop during periods of very hot or dry weather it may be
to get out the hose. Infrequent, thorough soakings are better
frequent minimal watering. In the early morning, water the entire area
the crown of the tree with a sprinkler until at least 3 cm (1 in.) of
has been applied. This can be measured by placing empty tuna cans
the sprinkler and watering until the cans are full. Repeat this
and your tree will start to perk up!
Mature elms will benefit from a fertilizer application every two or
years. Fertilizer can be applied on the surface of the soil or in
holes that are dug in the soil around the tree from the drip line
the outer edge of the canopy drips onto the soil) and outward.
in early spring before growth begins. For well established trees that
10 cm (4 in.) in diameter or more, apply 1 kg (2.2 lb.) of fertilizer
3 cm (1 in.) of trunk diameter using a 20:20:20 mix. Evenly
the fertilizer from the drip-line and out. After surface
make sure to water well.
Because most elms are very
and require specialized skills and equipment to reach the top branches,
is recommended that a professional tree pruner be hired to do the
Someone with ISA (International Society of Arboriculture) certification
best. Do not hire someone who “tops” trees as this simply
weedy, weak growth that may actually require more frequent
A listing of pruners with ISA certification is included on the last
Elms should be pruned every 5 to 7 years and also as soon as possible
any damage has occurred from storms, high winds or accidents. All
and dying limbs should be removed so that elm bark beetles do not use
wood as a breeding site. Do not prune between
1st and August 31stwhen the smell of freshly cut branches
attract elm bark beetles to your yard. Do not
the wood – it is illegal! Take all elm wood directly
the city landfill where it will be buried to make it inaccessible to
If you are pruning a
elm tree you may wish to consider the following pointers:
Whether you are pruning a
yourself or having someone else do the work, make sure that all pruning
is disinfected prior to and after each cut. Spraying your tools
a 50:50 mixture of bleach and water or with methyl hydrate (gasline
will prevent the spread of disease to healthy parts of the tree or to
trees. In our climate pruning cuts should not be painted or
in any way. Proper pruning is more important than wound treatment
quick healing of cuts.
- Prune all dead or dying
branches on a regular basis to improve the tree’s health and to avoid
- Prune to maintain the
shape or size of the tree.
- Prune crossing or
branches to avoid further damage.
- Prune to increase or
density of the tree branches. Generally trees should be thinned
produce an open crown allowing light and air to penetrate to the
ISA (International Society
of Arboriculture) Certified Tree Pruners located in Saskatoon
City of Saskatoon
SOS Elms Coalition
Saskatchewan Ministry of Environment
Coalition to Save the Elms
Gardenline - College
of Agriculture – University of Saskatchewan