Fall can be a good time for planting trees and shrubs.
To increase your chances of success significantly it is important to use
proper planting depth, supplemental watering and good mulching practices,
says University of Illinois Extension’s Nancy Pollard.
As you select a tree or shrub, keep in mind the
landscape purpose, available space, soil type and sun or shade conditions
it will face. Keep it covered during transport and well watered until
transplanted.
“The tree trunk and root ball will tell
you,” Pollard said. “While the tree is still in the container,
look for the point where the trunk slightly flares out and the roots angle
down — not at 90 degrees or up. Often this flare is buried
accidentally by soil or mulch. You may need to excavate the root ball down
to the root flare by hand.
“The natural flare should end up about two
inches above the surrounding soil line when planted in clay or poorly
drained soil, or exactly at soil level if the soil is sandy or
loamy.”
If the container is small, Pollard likes to dig the
hole, set the container in the hole to see if the depth is too shallow, and
when the height of the root flare is just right, remove the container so it
can be planted.
“If the container is heavy — it should be
if it has been watered — use a ruler or shovel handle to figure this
out,” she said. “The hole should be much wider than it is deep,
more saucer-shaped, like the natural shape of the root system. Rough up the
edges of the saucer-shaped hole as roots refuse to cross slick barriers.
Skip the amendments, but do break up any large soil clods.”
Next, it is time to remove the plant from the
container, place it on a tarp, and tease the roots out with your fingers if
the plant is not pot-bound.
“If you find a few circling roots in the ball,
carefully unwind them and spread them in the wide hole,” she said.
“This prevents them from choking or girdling the tree just as the
tree has reached the size you were dreaming about when you planted
it.”
If the roots prove too dense to tease out, make four
one-inch-deep slices with a knife down the sides of the ball and through
the bottom of the root ball as well. Then slide it into the hole.
“Backfill the hole with soil up to the base of
the flare. Do not cover the root flare,” she said. “I like to
partially backfill, add water, allow it to drain, and then add the rest of
the soil. Then water again. This eliminates air pockets and gets good soil
contact with the root ball.
“Do not stomp on the hole because that limits
root growth and makes a muddy mess of your shoes. Instead, let the water
settle the soil.”
Throughout the subsequent months, she added,
consistent watering is critical. But do not overwater.
“Water deeply, as often as is necessary to keep
the soil ball moist — about twice a week during warm weather, once a
week during cooler weather. Water about every three weeks throughout the
winter when there are thaws or if there is little rainfall,” she
said. “Winter winds continue to dry out the plants and the root
system is limited.
“Checking the plants in the winter also helps
you detect any frost heaving — particularly a problem in clay
soils.”
The new plant should be topped with a three-inch layer
of mulch such as bark chips to conserve water and insulate the roots. It
may also help reduce frost heaving.
“Spread the mulch,” she said. “It
will look like a flat, five- or six-foot-wide doughnut around the tree with
the trunk in the center hole. Keep the mulch a couple of inches away from
the trunk. Trunk bark is made to ‘breathe,’ not resist moisture
and soil microorganisms as the roots do.”
With care in tree selection, proper planting depth,
and good watering and mulching practices, the majority of trees are able to
overcome transplant shock.
“Water diligently the first spring and summer
and during future droughts,” she said. “If you follow these
tips, you can expect decades of delight for your efforts.”
For more information contact Nancy Pollard,
University of Illinois Extension unit educator in horticulture at pollard@uiuc.edu.
This article appears in Sep 18-24, 2008.
