Exercise 12
Aeration of Trees
OBJECTIVE
The objective of this exercise is to aerate tree root
zones.
INTRODUCTION
The general health of plant material can be harmed by
compaction of soil in the root zone. While aeration is
not a substitute for keeping traffic away from the root
zone, it can reduce the damage caused by compaction
VERTICAL MULCHING
Vertical mulching involves drilling vertical holes in an
even pattern throughout the root zone, then filling those
holes with a loose, porous material that allows air and
water to penetrate plant roots. To perform vertical mulch-
• Drill 3 inch diameter holes that are 12 inches deep
every 3 feet throughout the root zone according to
the pattern shown in Figure 12–1.
• Fill the holes with pea gravel, peat moss, or mulch.
trenches are excavated and then filled with a loose grow-
ing medium that allows air and water to penetrate the
plant roots. In addition to aerating the root zone, radial
trenching encourages new growth on roots damaged by
construction. To perform radial trenching, follow these
steps:
• Properly dispose of excavated soil.
PREREQUISITE EXERCISES
Students should have successfully completed Exercise5,
Tool Operation and Construction Techniques, before
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CAUTION
54 Exercise 12 Aeration of Trees
Operate power equipment under supervision.
Serious injury or death could result
from improper use of equipment. Follow
manufacturer’s instructions.
MATERIALS REQUIRED
• Two trees growing on a flat expanse of ground that
have compacted root zones. The trees should have
a caliper of approximately 6 inches or greater, a
canopy spread of approximately 30 feet, and be on
2 ⫻ drip line
= 3′
= 3′
97171_12_ch12_p053-055.indd 54 14/06/10 8:47 PM
barren ground or with turf planted in the
root zone.
• Pea gravel, ground mulch, compost, or loose soil
to fill excavations
• Round-nosed shovel
• Wheelbarrow
EXERCISE DESCRIPTION
Exercise 12 Aeration of Trees 55
Tree drip line
Figure 12–2 Radial trenching.
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