UNIVERSITY OF KENTUCKY ---
COLLEGE OF AGRICULTURE --- DEPARTMENT OF HORTICULTURE
Hyacinth Bean Cut Stems for the Cut Flower Market
Bob Anderson and Sharon Bale, Extension Floriculture Specialists
Hyacinth bean, Dolchios lablab (Family: Fabaceae), has been a novelty
garden plant in the U.S. for generations. This vigorous, twining vine is
characterized by large ternate purple-green leaves and purple petioles.
The vines produce hundreds of spikes of lavender flowers (JPEG
PHOTO) in late summer followed by long-lasting deep lavender-purple
pods. Hyacinth bean or lablab bean (a Chinese common name is pig-ears,
from the leaf shape) is primarily an ornamental annual vine in the U.S.,
but it is grown in China and other Asian countries as an edible pod.
| The long-lasting pods seem to be a natural product for cut stems
for the cut flower industry. In addition, the pods are so unique that they
could be used to decorate salad bars or harvested for ethnic food wholesalers.
Plan to grow the plants in the hottest part of the summer.
Hyacinth beans are easily grown from seed (JPEG
PHOTO). Depending on the climate, volunteer plants, from previous crops,
may develop as well. Purchased seed or saved seed can be sown in a greenhouse
(60oF night temperature and 75oF day) 4 to 5 weeks
before planting in the field. Plants should be transplanted before they
start to vine, for easiest transplanting. Seed can also be direct sown
in the field. Seed for our trials were planted May 1 into MetroMix 510
in 4" pots and fertilized once per week with 100 ppm nitrogen from 20-10-20
fertilizer. Plants were transplanted to the field in the first week of
June (JPEG PHOTO).
Hyacinth bean is a short day plant, but no specific
details about the flowering response have been determined.
Hyacinth beans grow vigorously and need to be supported
for best growth and easier harvest. In our trials in 1993 and 1994 at the
University of Kentucky Horticulture Research Farm in Lexington we used
nearly 200 lineal feet of fence that was approximately 5 feet tall. In
row plant spacings of 1 foot, 3 feet and 6 feet were evaluated in our trials,
but we found no yield differences between these spacings. Hyacinth bean
is a very vigorous vine and individual plants grew to fill the space on
the fence (JPEG PHOTO).
Plants were irrigated when necessary during the summer
and fertilized monthly, with the same fertilizer, through August. Pesticide
applications for grasshoppers were necessary in mid summer both years,
but no other insect pests were a problem even though many were present
in adjacent fields.
Hyacinth bean is a highly productive plant. In our trials, nearly 3800
commercial quality cut stems were harvested from Aug 20 to Oct 29 in 1993
with warm September weather. Yields were reduced to 1800 cut stems in harvests
from Aug 20 to Sept 10 in 1994 due to cool September weather. The average
number of commercial quality cut stems harvested was as high as 18 stems
per lineal foot of row.
Cut stem lengths varied from 10 to 35 inches when
harvested from hyacinth bean vines. The percentage of stems in standard
cut flower grades were nearly identical in both plant densities in both
years (Table 1). Longer stems were more common in the early harvests than
in later harvests in both years.
Table 1. Total number and percent of commercial quality cut stems of
hyacinth bean in standard cut flower stem length grades harvested in 1993
||Cut Flower Stem Length Grades (in)
Over 80% of the total harvest of cut hyacinth bean
stems occurred in the first two weeks of harvest in late August in 1993
and 1994. Yields were so high that harvest occurred on 2-3 day intervals
for 12-15 days. However, the number of stems harvested dropped quickly
after the first two weeks.
After our preliminary work in 1992, we hoped that
harvest would occur over 6-8 weeks so commercial growers could supply the
market for a period of time; unfortunately this was not the case.
The number of purple fruit ranged from one to thirty
per cut stem of hyacinth bean with a mean fruit number of nine fruit per
stem. Approximately 90% of the cut stems had 4 to 12 fruit on each stem.
This number of fruit per stem was appropriate for use as a cut stem in
In preliminary vase-life studies in 1992, it was determined
that fruit should be harvested when all fruit on a stem were mature enough
that the pod was swollen from seed development. This was the criteria used
for harvest in our trials.
Vase-life studies were continued in 1993. Vase-life averaged 10 to 11 days
in replicated trials with deionized water, tap water, Flora-life® and
Chrysal® with no differences between the treatments.
Stem storage was evaluated in 1994 because the harvest
was so heavy for only a few weeks. Conditioned
stems could be stored dry for up to two weeks at high humidity and 34oF
in sealed boxes but vase-life decreased 2-3 days after this long term storage.
Some seed catalogs offer named selections of hyacinth
bean but no comparisons were made in our trials. More than five varieties
are available in Asia, some with green leaves and fruit.
Hyacinth bean cut stems are a unique item for cut flower
arrangements. Some local and regional florists enjoyed the special color
and texture that hyacinth beans offered their arrangements while others
had little interest in the use of these stems. With yields as high as 15
cut stems per lineal foot of fence, the potential returns could be $3.00
to $4.00 per foot for the short term harvest and marketing of this summer/fall
crop. Yet, there is no established market for hyacinth bean cut stems and
no guarantee that any would be sold to floral wholesalers or retailers.
Bailey, L.H. 1930. The Standard Cyclopedia of Horticulture. The Macmillan
Co., New York, NY. Piper, C.V. 1915. The bonavist, lablab, or hyacinth
bean. USDA. Bulletin 318.
Saraswat, K.S. 1986. Ancient crop economy of Harappans from Rohira, Punjab
(c. 2,000-1,700 B.C.). Paleobotanist. 35(1):32-38.
Singh, P. and M.L. Pandita. 1980. Effect of spacing, plants per hill and
training on growth and yield of sem (Dolichos lablab L.) hyacinth
beans. Indian J. Horticulture 37(4):388-391.