124 J.E. FAUST, J.M. DOLE, AND R.G. LOPEZ
and (4) the ease of transfer of pathogens amongst the stock plants, which
affects all cuttings harvested from those stock plants; thus, the stock
plants must be started from virus-indexed and pathogen-free plants,
which require rigorous sanitation protocols.
Stock plants consist of highly branched plants that have been grown
for several months, after which time the shoot tips of the largest stems
in the canopy are harvested and propagated as unrooted cuttings. In the
early 1900s, growers in temperate locations of North America, Europe,
and Asia would maintain stock plants from which cuttings could be
harvested upon demand. However, this required valuable greenhouse
space and substantial heating costs during the winter.
Chrysanthemums were amongst the first floriculture crops that were
grown as stock plants in warmer locations and then sold as unrooted
or rooted cuttings to growers in temperate climates to flower for the
local retail market. In the United States, chrysanthemum stock plants
were produced year-around in the 1950s in locations that were rela-
tively warm, such as California and Florida. In the 1960s, these stock-
plant production methods were copied by producers of other species,
such as poinsettia.
As labor costs increased in the industrialized countries, stock-plant
production facilities moved to countries with warm climates and low
worker wages. One of the first “offshore” production locations for the
North American market started with zonal geraniums in Puerto Rico
in the early 1970s (W. Oglevee-O’Donovan, personal communication).
Meanwhile, the energy crisis of the 1970s resulted in cutting produc-
tion for the northern European market moving to the southern Euro-
pean countries of Italy, Spain, and Portugal, where it lasted for a decade,
until high labor costs drove production further south to the Canary
Islands.
This trend of moving production sites has continued nearly every
decade ever since. The ideal stock-plant production location has sev-
eral characteristics. First, stock-plant production is extremely labor-
intensive, so there must be a sufficient supply of relatively low-wage
labor. Second, the proper climate is critical. For most annuals and
perennial species that grow well in temperate climates, this normally
entails 500–1600 m elevation locations in subtropical-to-tropical cli-
mates that do not require utilities for heating and cooling. Species of
tropical origin are grown at lower elevation locations since heat stress is
not a limitation. Third, political stability of the host country is essential.
Fourth, transportation infrastructure is absolutely necessary, including
good roads to the airport, and an airport with refrigerated cooling facil-
ities and regular, direct flights to important export markets.