The gardens of Vizcaya, a National Historic Landmark
in Miami, are magical. They're full of centuries-old sculptures,
inviting secret garden spaces, and many mature trees. On top of
Vizcaya's Garden Mound, an enigmatic structure at the southern
end of the gardens, enormous planters were constructed as part
of the 25-foot (7.6 m) tall structure. These planters were designed
to hold live oak trees (Quercus virginiana), which were intended to
cover the Mound and create a green mountain of foliage.
When the structure was completed in 1917, the containers were
planted with fully mature live oak trees already a century or
more old. The trees were harvested from various sites around
Vizcaya in order to save them from destruction by the building
boom that had taken over Miami at that time. The trees were
cut back severely, dug, and transported by truck and boat to
Vizcaya, where they were hoisted atop the Mound, planted, and
secured with guy wires.
Vizcaya is located on the shores of Biscayne Bay and is extreme-
ly vulnerable to hurricanes. Because of the height of the Garden
Mound, the live oak trees there receive the full force of the winds
off the Bay. Until 2010, the oaks had never been maintained in
their nearly 100 years of growth at Vizcaya, and they showed
extensive storm damage and declining vigor as a result.
Beginning in 2010, shortly after Vizcaya established its horticul-
ture program, the 35 Garden Mound live oaks were designated
as historic trees—critical to Vizcaya's history and garden inter-
pretation. In recognition of this designation, their root systems
were inoculated with mycorrhizae and they received an initial
pruning to correct decades of damage, overgrowth, and dead
branches. The following year, the trees were placed on a biannu-
al maintenance program to increase their vigor and storm resis-
tance and to address visitor safety concerns. The pruning, which
takes a full five days to complete, includes crown balancing,
selective thinning, a slight canopy reduction, and removal of
dead wood. More recently, the trees have been experimentally
examined for integrity via sonic tomography.
Seven years after the horticulture program was established,
by Ian Simpkins
32 CityTREES
