Trunkline Magazine (Louisville Zoo) March 2019 | Page 15
GARDEN TALK
A Good Time
to Plant a Tree
By Matt Lahm, Assistant Curator of Education
What better way to celebrate Earth Month than by
planting a tree? Planting a tree should be thought of as
a lifelong investment; how well your investment grows
depends on selecting the tree species that’s right for
you and proper care during and after planting. Ideally,
trees should be planted during the dormant season:
late fall after leaf drop or early spring before budbreak.
However, healthy balled, burlapped or container trees
can be planted throughout the growing season if given
the proper care. Here is our 11-step process to help
your new tree get established and thrive!
1.
2.
3.
4.
5.
Select a suitable species for the location. Before
you dig, follow the LG&E and KU Right Tree, Right
Place guidelines and call 811 or visit kentucky811.
org to ensure you’ve located all underground
utilities to avoid future issues.
Find the base of the tree trunk and remove
excess soil from the top of the root ball so that
it will be partially visible after the tree is planted.
This will give a more accurate height of the root
ball to determine how deep to dig your hole.
Dig a shallow, wide planting hole. The hole
should be 2 – 3 times wider than the root ball,
yet only as deep as the root ball is tall. This assists
with breaking up the surrounding soil for new
roots to grow into.
Before planting, cut and remove any plastic
containers, wire baskets and rope, especially if
they are encircling the trunk. Straighten or prune
any roots that are wrapped around the root ball
if it was in a container. Lay down the tree and
prune any cross branching, branches growing
inward toward the trunk or damaged limbs.
Set the tree at the proper depth. Most tree
roots are found within the first 12 – 14 inches of
soil. Planting a tree too deep is one of the most
common mistakes made. It’s better to plant the
tree with the base of the trunk at grade level or
1 – 2 inches above grade. If the tree is planted
too deep, the newly developing roots will have
difficulty growing due to the lack of oxygen.
6.
7.
8.
9.
Before backfilling, straighten the tree in the
hole. Use of a level can be helpful on hillsides.
Backfill the hole with soil and press firmly. You
can use the original soil, but if it’s mostly clay
soil, backfilling with good organic topsoil is best.
remove any fabric or plastic wrapping on the root
ball. Firmly pack the soil around the root ball to
eliminate any air pockets that will dry out the
roots or cause the soil to settle unexpectedly and
the tree to lean. Do not fertilize the tree at this
time. Light watering can be done and will assist in
reducing air pockets.
Stake the tree if necessary. Use two opposing
stakes with wide, flexible material that won’t
injure the bark. When wrapping the material
around the tree, avoid encircling the trunk and
only wrap each piece of material around once.
Apply a mulch around the base of the tree.
When mulching, less is more! Mulch is beneficial
for trees as it helps retain soil moisture and avoid
drying, keeps roots from overheating and helps
minimize competition with other plants. Only
about 2 inches of good organic mulch is needed.
Piling mulch up against the trunk of the tree,
creating a “mulch volcano” can be detrimental to
your tree by limiting available oxygen. Retaining
too much moisture may cause root rot and decay
the living bark.
10. Follow up care: water enough to only keep the
soil moist, not wet. Prune and fertilize after the
first growing season if needed.
11. Enjoy your new tree!
A special thanks to the LG&E and KU Foundation for supporting the Zoo's
commitment to tree planting and preservation of wildlife habitat.
Louisville Zoo Trunkline • Spring 2019 • 15