TREES AND SHRUBS
Trees must be planted at the
right depth if they are to establish themselves and flourish. Planting too
deeply and under- and over-watering are the most common and serious planting
errors. In well-drained soil you want to locate the topmost root in the root
ball so that it will be level with the soil surface. The planting hole should be
at least two times wider than the root ball. In poorly drained or compacted
soil, take extra precautions to ensure that roots are not suffocated by the
water saturation typical of these soils (see diagram). Loosening compacted soil
before planting can dramatically increase the rate of root growth and root
penetration into the soil. Establishment time is sped up, reducing the period of
the tree’s vulnerability to pests, disease and drought.
Trees grown in containers
can be removed and planted directly in the prepared holes. If the
plant shows a
lot of larger roots at the surface of the ball, these roots should be cut so
they will not strangle the plant later on. The soil used to fill in around the
root ball is called backfill. The best backfill will be the loosened original
soil dug from the hole. The best additive to the soil is water. An excess of
soil-"improving" amendments may serve only to discourage roots from
leaving the area where they are added. Of course, if you have contaminated soil
or soil that
won't drain, you are going to have to add something more like
normal soil to the planting area. Tamp the soil lightly, then settle the soil by
watering the plant in.
latest research indicates that pruning does not help overcome transplant shock
unless the plant is receiving insufficient irrigation. Pruning of trees, if
required, should not be done until a year or so following planting. Many trees
do not require staking after planting. Do not stake a
tree unnecessarily as it
tends to prevent the normal increase of trunk caliper, resulting in an
elongated, thin, weak trunk. Besides, it is not an aesthetically pleasing thing
to see in your yard.
It is normally not
necessary to fertilize at the time of planting. Wait until the plant is somewhat
established and begins to grow – say 2-3 months after planting. A slow-release
fertilizer is safer
to use than a highly soluble granular type, though when the
plants get bigger, this becomes financially extravagant. Eventually, you are
going to have to use the soluble types and learn
how to apply them without
burning the roots. We fertilize in-ground plants at the drip line (the circle of
ground below the edge of the canopy). This encourages roots to grow out from the
trunk and stabilizes the tree. Less fertilizer more often is safer and also
better for plant growth because you will lose less material due to water
is not as critical to have some particular NPK configuration, as it is just to
fertilize with something. NPK stands for Nitrogen, Phosphorus and Potassium, the
"macronutrients" and the three numbers that characterize different
types of fertilizer. Fertilizers that contain micronutrients are preferable for
routine (3-4 times per year) use - especially in the poor soils of South
Florida. Many people do not realize that the typical south Florida soil is
limestone, marl, or sand fill brought in by the homebuilder. Because of this,
gardening here resembles hydroponics more
than anything else, for there are
essentially no nutrients in this soil. You have to add them to get plants to
grow properly. You will have to experiment with the quantity, remembering that a
large concentration in one spot will burn foliage. You should never see little
piles of dry fertilizer on
the ground. Thorough scattering of fertilizer is the
best protection from burning.
Standard fertilizers (as
opposed to the slow-release type) are basically a mixture of different salts.
Salts are ionic compounds that disassociate (dissolve) fairly easily in water.
So, if these salts land on a wet leaf - and there is no way to avoid hitting
some foliage in garden plantings - it will start to dissolve right on the surface
of the leaf. A very high concentration of salt solution results, which can cause
severe burning. The best thing to do is to fertilize when leaves are dry, then
water thoroughly, wetting down the foliage to wash off any solid fertilizer. If
you see residual fertilizer on the leaves, be sure to rinse it all off right
away. Be especially careful about those areas found in many tropical plants
where large upright leaves emerge from a stalk, as these can hold large amounts
of fertilizer like little cups.
Using an 8-3-9 or similar
formula with the following minor elements: magnesium, manganese, boron, copper,
zinc, iron and molybdenum are ideal. (The second number is usually lower in
fertilizers designed for this area because phosphorus leaches away less rapidly
than the other components.) We use this on all the plants in the ground except
palms (8-4-12 with enhanced minors) and bananas (high potassium), which have
special fertilizers specifically for those plants. There are also specialty
fertilizers available for plants that require acid soil, such as gardenias.
These fertilizers are generally named after the plant they are designed for.
especially tropicals like heliconias, will benefit from a foliar application of
epsom salts (magnesium sulfate), especially at the start of the growing season.
We use 1 tablespoon horticultural epsom salts per gallon of water and drench the
foliage once a week or so after spring cleanup until the plants start to green
You will notice that
every fertilizer we use has minors (also called micronutrients). These aren't
needed in huge quantities but they are needed, or deficiency symptoms will
develop. We also add minor elements to our container plants.
In this area it is also
recommended to use a micronutrient foliar spray twice a year. Fruit trees
especially will benefit from this as well as the application of chelated iron
(such as Sequestrene 138 or Microlific Iron EDDHA) dissolved in water and
applied at the root crown two or three times a year. Non-chelated commercial
iron additives don't work well in our alkaline soil.
We do not fertilize
in-ground plants between the beginning of November until some time in
whenever possible. (Signs of any deficiency will over-rule this policy.) That
leaf growth initiated by the administration of nitrogen will not likely
be present and susceptible
to possible extreme cold snaps during this time.
A NEWLY PLANTED TREE
OR SHRUB - IRRIGATION
When Trees die,
blame is often placed on pests, disease, the method by which they were produced
or the plants themselves. The truth is that many trees die from too little or
too much watering during the first few months after planting. Trees are likely
to get too little water in well-drained soil and too much in soil that is partly
irrigation schedule for quickly establishing trees in well-drained sites: Daily
for 2 months, then 3 times a week for 3 months, then weekly until established.
of tree establishment period in South Florida with the above irrigation
than 2" diameter trunk: 2-4 months
to 4" diameter trunk: 5-9 months
4" diameter trunk: 10+ months
luck on growing a health tree or shrub.