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Mulch to do
this spring
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Like a brightly colored rainbow
after a big summer rainstorm, green grass emerged
from long brown landscapes around Wyobraska this
past week promising an end to the longest winter in
recent memory. With the first daytime
temperatures since September reaching into the 70’s
Wyobraskans were finally out beginning their spring
lawn and landscape clean-up work this week. It’s a
late start on the spring landscape work, so there
may be a temptation to skip some of the usual spring
landscape chores and just concentrate on the more
obvious work that needs to be done. If you were
thinking about putting “mulching or remulching your
trees and landscape beds” on the postpone until
later list, my strong advice is—don’t do it. |
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There is no single right time to apply mulch. For a
variety of reasons, spring and fall tend to be the
main “mulching seasons”. Spring is often a good
time to add mulch to perennial beds, simply because
that is the time, right after cleaning up the old
stems, when a new layer of mulch can be placed over
the entire bed without having to work around any
actively growing plants. As a rule of thumb,
March/April is the best time to remulch perennial
beds.
A six foot diameter circle of
mulch around a young tree is the minimum size of
mulch area that will insure quick establishment and
healthy growth. |
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Previous Articles
A
Loooooong Winter
March 11
Just Dirt
March 18
Horse Manure & Hot Air
March 25
2009
Articles
2008 Articles
2007 Articles
2006 Articles
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Regular readers of this column
know that “Mulch” is one of my favorite topics—for
the simple reason that in 30 years of working with
plants in western Nebraska and eastern Wyoming, I
have seen nothing that improves the health of
landscape plants like mulch. And as I drive around
Wyobraska communities in recent weeks I have noticed
many lawns where the grass has been allowed to grow
right back up to the base of the trees. For trees
growing in lawns, mulch is literally the key to
survival. The numbers are overwhelmingly
convincing. In my experience, over 80% of newly
planted trees that aren’t mulched die within three
years of planting. Conversely, over 80% of newly
planted trees that are mulched are thriving after
three years. One of the primary benefits of mulch
for newly planted trees is that it keeps lawn mowers
and string trimmers away from the tender bark of
young trees. Most of the difference in rates of
survival between mulch and un-mulched newly planted
trees is undoubtedly due to the ability of mulch to
keep the lawn mowers and string trimmers away from
the base of trees.
The statistics are not quite as stark for older,
established trees growing in lawns, but the evidence
is still clear that trees, even mature trees, remain
healthier if they continue to have mulch around
their trunk. The larger the mulch area, the
healthier the tree.
Mulch provides a variety of benefits beyond just
protecting the trunks of trees from lawn mowers and
string trimmers. Those benefits include moisture
retention, soil temperature moderation, elimination
of competition from other plants like grass, and
perhaps most importantly, the development of active
soil ecosystems on which the roots systems of many
trees depend—in other words, mulch is the original
slow release fertilizer. For shrub and perennial
beds, mulch offers one additional benefit—weed
control. Properly applied and maintained mulch
reduces 90% or more of weed germination, making weed
control a minor maintenance task.
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An 8 foot diameter circle of mulch is better. The
mulch should be 4 inches thick. Grass will grow
rather quickly into this mulch area through the
spring and summer. Do not try to pull this grass or
trim it down with a string trimmer. The easiest way
to control grass in mulch is to use round-up or a
similar non-selective contact herbicide. Spraying
the encroaching grass two times a season will
normally provide good control. It’s easy and fast.
Some mulch products are clearly better than others.
The best mulch, in my opinion is shredded hardwood.
It is widely available in either bagged or bulk
form. Its shredded texture keeps it from blowing
out of beds in even the windiest of conditions. Its
composition allows it to break down at a moderate
rate and develop a healthy soil ecosystem. And its
color gives the bed a natural, soil-like color. The
shredded hardwood mulches are generally made from
either the byproducts of hardwood timbering
operations or the recycling of municipal tree
debris. They generally contain a mixture of leaf,
bark, and wood tissues—an ideal blend for feeding a
soil ecosystem.
Shredded redwood has become a
popular mulch in Wyobraska. It is a good mulch in
that it does not blow in windy conditions and it
maintains a nice reddish-brown color over time. It
lasts a long time—up to four years, which is both an
advantage and a disadvantage. While it does not
need to be replaced as often as other mulches, it
also does not do as good a job of developing a
healthy soil ecosystem—in other words, redwood mulch
is not as good a slow release fertilizer as shredded
hardwood mulch. Shredded redwood is only available
as a bulk product. Comparable mulch that is
available in bags is shredded cypress mulch. Rock
and ground rubber are not good mulches.
Happy Easter! |