of Composting & Organics Recycling, December, 2002
park produces own compost for container mixes and topdressing, and most
recently, in the transformation of a barren island into a new location.
part of its goal to save as many original canopy trees as practical,
this 40,000 pound black olive tree was relocated and given the full
Click To Enlarge
and Gardens (PJ) has been operating since 1936 in South Miami, Florida.
Historically, the success of PJ has been based upon its collection of
parrots and flamingos, its colorful parrot show, and the lush and highly
manicured tropical gardens. Since 1988, when the park was purchased from
the original founding family, the new owner has been adding different
species of animals and more shows. The collection of tropical plants (species-wise)
has tripled in number to approximately 1,000. Hundreds of species of tropical
plants are grown in an outdoor setting year round. There is also a one-acre
plant nursery on-site for growing new and replacement plants for the park.
years ago, I began to experiment with different Integrated Pest Management
(IPM) practices. The use of restricted pesticides, fungicides, and nematicides
has been reduced to the point where no restricted chemicals have been
used since 1994. A considerable reduction in commercial fertilizer use
also has been achieved. The major components of this program have been
the adherence to specific cultivation techniques, such as selective pruning,
closely monitored irrigation, and the use of mulch and our own park-produced
of plants that are containerized have straight compost as a potting medium.
Other mixes include peat moss, perlite or pine bark, depending on the
species of plant. We have found that commercial mixes break down, causing
the roots to rot because water stays in pot. In general, compost helps
control moisture, which in turn cuts down on irrigation. And we fertilize
less, which makes nutrients less available to insects. Overall, the IPM
program has enabled natural predators to survive. We haven't sprayed for
spider mites in the park for about ten years; previously, the beds were
sprayed ten to 15 times per year.
always been a rudimentary compost pile at PJ, primarily to reduce trash-hauling
costs of animal-derived wastes and bedding. The compost was only used
as fill. In 1993, the Department of Environmental Resources Management
(DERM) of Miami-Dade County was going to make us remove the pile permanently
because of regulatory issues. About this time, I completed the Municipal
Compost Management course with Cornell University and was able to get
a composting license for PJ in my name. Gradually, compost became a cornerstone
of our IPM program. It is used as a soil additive throughout PJ and as
the main component of the potting soil in the plant nursery.
material (except food scraps) produced park-wide is composted (aerobically
in a single windrow) next to the plant nursery. Feedstocks include plant
and animal residuals, plus soiled sand from the petting zoo. Piles are
turned every three to four weeks with a front-end loader. During the winter
months, they are turned less frequently. A contractor brings in ground
tree trimmings, which are thermophilically treated and used as mulch.
Without the composting operation, I estimate that PJ would be filling
a 20-yard dumpster each week that would have to be hauled away, as we
are constantly pruning and cutting back foliage at the park. In 2001 our
composting program at PJ won the Environmental Business Practices Award
with the Greater Miami Chamber of Commerce.
Soils At New Site
PJ site, now surrounded by very high-priced homes, will be closing when
a new location opens on Watson Island in the Spring of 2003. The challenge
is that Watson Island is an 86 acre manmade "spoil" area created
in the early 1900s from sand and rock dredged up from the creation of
ship channels at the adjacent Port of Miami. The soil consisted mostly
of a calcareous-quartzite material with little organic matter, which raised
the issue of whether or not it could be used for intensive landscaping.
site was only six to eight feet above sea level and considered a flood
zone, all structural pads had to be raised to 12 feet above sea level.
The top four feet of almost the entire site was stripped off and stored
for landscape fill. Dredgings from the ship channels at the nearby Port
of Miami were used for structural fill. That base was covered with the
landscape fill; compost produced at the original PJ site was used as a
soil additive. As part of the transition to the new 18-acre site, compost
also has been used to create hundreds of feet of berms as extra growing
areas for plants that are now being relocated.
began on Watson Island, about 150 trees were growing on the site. Many
were large (up to 3 feet diameter at breast height) canopy trees that
had been on the site for 20 to 30 years. Large canopy trees have been
an integral part of the garden at the original PJ site, helping to keep
the temperature at ground level cooler. It was decided to save and utilize
as many of the original trees as practical. Utilizing existing trees from
the site also would give the garden a more finished look when the new
Park opens next year.
of the island's trees were in good enough condition (or were not considered
invasive exotics that would have to be removed) to be considered for relocation.
The trees were relocated to a holding area adjacent to the construction
Once the site was contoured and landscaping areas prepared, the 60 largest
trees were brought back -- all receiving a four to five inch topdressing
of compost over the top of the entire root pad one month after planting.
These root pads were from 15 to 25 feet in diameter and up to six feet
deep. The compost was never placed against the trunk of the tree and never
higher than the root collar, since that could cause rot problems.
applications, two to three inches of well-broken down tree trimming mulch
were laid on top of the compost to reduce the temperature of the soil
surface thereby minimizing evaporation. All other landscape areas are
being heavily mulched as well. Our goal is to improve water holding capacity,
reduce weeds that compete with the landscape plants for water and nutrients,
and generally, add organic material to the soil.
months later, the second set of trees was brought onto the site and installed
in permanent locations. These trees and many others since brought in from
other locations have received a topdressing of compost and mulch over
their root balls. About one month after the compost is applied, the trees
are lightly fertilized with 4-7-5 fertilizer.
Growth of Roots
result noticed within a couple of months after the compost application
on top of the root balls was the rapid growth of hair roots. These tiny
roots are so thick that on certain species of the faster growing trees,
the entire layer of compost can be cut and peeled back, exposing the surface
of the old root ball. In addition, the foliage on all of the trees is
healthier (greener) and larger than the foliage on the trees before they
were moved. Throughout the process of root pruning, excavation, and moving
the 80 trees, I never noticed any earthworms in the root pads. Now the
top composted layer and the adjoining layer below host a population of
earthworms -- a very good indicator of a healthy soil. All of the trees
from both mobilizations now seem to be well established. Composting and
mulching are being done to all canopy and subcanopy trees being planted
at Watson Island with excellent results.
Jeff Shimonski has been with Parrot Jungle and Gardens since 1975. In
1988, he became the Director of Horticulture.