The Care and Feeding of Olive Trees
PLANTING
Olive trees require a well-drained soil and a sunny
position.
Avoid sites where water
stands during rainy periods or where ground water seeps into
a hole two feet deep.
Do not, however, confuse
the olive for a desert plant. It needs regular watering to
thrive.
Insufficient water will
cause your tree to suffer, and even die if left too dry for
too long.
Choose a site that
receives at least six hours of direct sun per day. Full sun
is ideal.
Plant your tree at the depth
it has been growing in the pot. Do not amend the soil with
organic material, moisture-retaining polymers, fertilizer or
anything else. Simply plant in the native soil (provided it
is well-drained) and backfill with the same.
If your tree requires staking, it will already have a stake
in the pot.
A very young tree may require
a heavier stake as it grows. Once the trunk caliper reaches
1.25 inches or more in diameter (or perhaps less for
shrub-form or short trees), it will no longer require a
stake.
Until then, use a stake large
enough to hold the trunk upright. Put the new stake in the
same hole the previous stake occupied and tie the tree to
the stake with arborists' tape such as comes with your
staked tree.
Do not use wires, water
hoses, cloth, cables, guying systems or other means of
securing your tree. A good stout stake and the proper tape
is all you need.
FERTILIZATION
Olive trees do not need special olive tree fertilizer but
results will be exponentially more satisfactory with a good
nutrition regimen. If planting is done after mid-August but
before March 1, do not fertilize at the time of planting;
wait until spring.
Otherwise, fertilize after planting and
regularly throughout the growing season. How regularly will
depend upon the type of fertilizer used.
We at Olive Tree Growers prefer to use a
premium slow-release fertilizer with essential minor
elements (zinc, boron, calcium, etc.). Use a fertilizer that
has a nitrogen analysis of at least ten percent.
Olive Tree Growers believes that some sort of
minor elements package is important, as many soils are
lacking in some essential minerals which aid plant growth in
several ways.
A fast-release farm-type fertilizer may be used according to
label directions. Many such fertilizers contain some minor
elements and are widely available. Be sure to water very
well after application. These fertilizers are generally not
for use on plants in pots.
Liquid fertilizers may be used (again, a formulation with
minor elements is best) but it should be remembered that
liquid feeding is a fleeting thing and must be repeated
often.
Organically-derived fertilizers are available and a good
thing, though often more expensive and rarely contain the
percentage of nitrogen preferred by olive trees.
Top dressing with organic material such as
composted manure or kitchen compost can be done but the
grower should consult the current literature. It can be
difficult to achieve a good balance of nutritional elements
by this method.
It is environmentally responsible but
requires more study and understanding by the gardener.
Always avoid placing compost or any fertilizer next to the
trunk of the tree.
Whatever type of fertilizer is used, it is best to feed
lightly and often during the growing season. Avoid heavy
applications of fast release fertilizer that could damage
plants and leach or run-off into groundwater.
Always read and follow label instructions. Do
not fertilize after mid-August or before mid- March unless
you live in a very warm climate.
If your tree is planted in a lawn area, take care that lawn
maintenance practices do not harm the tree. Do not allow
"Weed and Feed" products to be used within 30 feet of your
tree.
These products are designed to feed lawn
grasses and destroy other plants. Remember that the roots of
any tree extend far beyond the drip-line of the branches.
Also, do not allow weed-eater operators near
your tree. Weed-eater operators kill thousands of trees
every year by "girding," or removing the bark from the bases
of trees.
MULCH
Wood chips are bad, okay? Do not use wood chips, cypress mulch or
any cellulose product for mulch. These products are high in carbon
and rob the soil of nitrogen and other nutrients in the
decomposition process.
They also hold too much water in
wet periods and, once dry, shed irrigation water and
rainfall like a shingle roof.
We prefer to use only pine straw
for mulch and keep it back several inches from the trunk; do
not allow a build-up of decomposed mulch around the base of
the tree trunk.
WATERING
Once established, olive trees are among the most
drought-resistant trees in the world. That does not mean
they prefer to suffer for water.
You will have to water
sufficiently to get your tree established and thereafter as
necessary during dry periods. No one can give you a formula
for that; you will have to observe and evaluate.
Low volume spray irrigation can
be used effectively, but drip irrigation is of little or no
use in sandy soils.
PRUNING
Olive trees may be pruned to the desired shape. Some people
prefer a tree form; others like a rounded shrub as is done
in production groves to facilitate picking of the fruit.
Pruning between mid-February and
the ripening of fruit in the fall, except for the lightest
tipping of new shoots, can result in a reduced crop the
following season.
Otherwise, prune to the desired
shape. Keep in mind that olives bear their fruit on the
previous year's new growth.
PESTS
The only pests we have known to attack olive trees outside
of olive producing regions is an armored scale insect. It is
not common but should be watched for, especially if your
site has other species prone to harbor scale insects.
Inspect the trees by looking
under the leaves and in the branch axils for a dark bump the
size of a "BB." These insects do not move in the adult
stage; they attach themselves like barnacles.
The presence of sooty mold on
leaves and bark, or ants crawling on your tree, indicates
the presence of scale insects.
If scale is found, it may be treated with a variety of
products, depending upon personal preference. It may also be
removed by hand if you have only one or a few trees.
If you have other plantings that
attract pests such as thrips or stink bugs, these may also
have a go at your olive tree. Consult your local garden
center or pest control specialist about the control of
pests. Regulations vary from place to place.
Finally, be sure to keep ant colonies away from your trees.
Source: Olive
Tree Growers