Horticulture Science
Lesson 55
Caring for Fresh Cut Flowers
and Foliage
When a flower is cut, what are
its needs?
• Even after fresh flowers have been
removed from plants, they continue to
photosynthesize, that is, they produce food
from sunlight.
• Two needs for
maintaining the health
of cut flowers are water
and sugar.
When a flower is cut, what are
its needs?
• 1. A flower is 90 percent water.
– Plant cells that are filled with water are called
turgid.
– As the flowers continue to photosynthesize and
respire, they will need water.
– A water analysis can be conducted to determine
quality.
When a flower is cut, what are
its needs?
• 2. A pH test of the water will determine
whether water is acidic or alkaline.
– An acidic pH has a reading below 7, and pH
readings above 7 indicate an alkaline solution.
– Slightly acidic water improves water uptake.
– If a floral preservative is added to water, it will
increase the acidic level, thereby increasing
water uptake in plants.
When a
flower is
cut, what
are its
needs?
When a flower is cut, what are
its needs?
• 3. Water is classified as either hard water,
that which contains a high level of
minerals, or soft water, which has been
treated to lower the mineral level.
– Softened water has been treated with salts to
remove dissolved minerals.
– The addition of salts to the water lowers the
water quality for flowers.
When a flower is cut, what are
its needs?
• 4. Salinity is the measurement of the total
dissolved salts in water.
– Salt clogs the xylem of the floral stem,
preventing water movement, resulting in wilting
and weakening of the stem.
– Salinity needs to be less than 200 ppm.
When a flower is cut, what are
its needs?
• Sugars are the food source for cut flowers.
• The two most common sugars are sucrose
and dextrose.
– The flower gets these sugars either from being
stored in the flower tissues or through
supplemental sugars provided in a floral
preservative.
When a flower is cut, what are
its needs?
• Fresh cut flowers require a healthy
environment.
• 1. Fresh cut flowers should be placed in an
environment free from ethylene gases,
which cause deterioration in the flowers.
– Fruit should not be stored in a floral cooler
because this causes ethylene gas exposure.
Conditioning
• 2. Conditioning is the preparation of cut
flowers and greens when they arrive at the
design site.
– The conditioning process involves the cutting of
stems, adequate solution uptake by the
materials, and cooling.
• a. Flower stems should be re-cut and
defoliated to a point that no leaves will be
in the water solution.
Conditioning
• b. Flowers are placed in water that is
approximately 100 to 110°F or about the
temperature of a warm bath.
– Warm water speeds uptake and contains less air than
cold water.
– Allow the flowers to take up water at room temperature
for several hours before placing them in a cooler.
• c. Once the flowers are full of water, they can be
placed in a cooler that is 34 to 38°F.
– Floral coolers are better than refrigerators because they
provide controlled humidity levels in addition to cooling.
Conditioning
• Another important factor in the handling of
cut flowers and greens is sanitation.
– Sanitation or cleanliness improves the vase life
of flowers.
– Hands, tools, knives, shears, containers and
work areas need to be kept sanitary.
– Introduction of bacteria and organisms can be
avoided by cleaning work areas, coolers and
containers on a regular basis.
Senescence
• As soon as a flower is cut from the mother
plant, it begins to deteriorate because the
flower no longer has a water or food
source.
• The flower will eventually die, which is
referred to as senescence.
– Major causes of flower deterioration and death
are determined by:
•
•
•
•
•
genetics
lack of water
time of harvest
Ethylene
disease or damage
Senescence
• The life of each flower is based on its
genetics.
• The natural lives of flowers differ between
species.
–
–
–
–
–
The flowers of the daylily live just one day.
Dutch irises live 3–5 days.
Roses have a life of 5–7 days.
Carnations last 10–14 days
Chrysanthemums live 14–21 days.
• The goal is to obtain the maximum life of
each flower as allowed by nature.
Senescence
• Wilting is caused by the inability of plant
tissues to absorb enough water to replace
water lost by transpiration.
– Transpiration is the loss of
water from plant tissues.
• The rate of transpiration
warm environments with low
humidity.
• Transpiration can be reduced
avoiding drafts and
handling flowers.
increases in
by
over-
Senescence
• 1. Blocked vascular tissue can restrict the
movement of water within a plant and
cause wilting.
– Stem blockage is the most common cause of
poor absorption.
– The xylem becomes clogged and no water
movement can occur in the stem.
• 2. Flowers and foliage that are fully
hydrated are said to be turgid.
Senescence
• The timing of flower harvest influences
flower life.
• 1. The time of day when flowers are cut is
important.
– Flowers should never be cut
when they are wilted.
– Avoid cutting in the heat of
the day.
– Evening is the best time to
harvest because plants have
been making sugars throughout the day.
– Morning is the second best time to cut because
plants are full of water.
Senescence
• 2. The stage of flowering should be
considered.
– The best time to harvest is just before a flower
is fully open.
• Exceptions to the rule
the daisy and
crops, which are harvested in
bud stage, and the calla
which will not
further once it
include
flowering bulb
lily,
develop
is cut.
Senescence
• Ethylene gas promotes senescence.
– Ethylene gas is a natural plant hormone
produced by aging flowers, foliage, fruits, and
vegetables.
– Common signs of ethylene exposure include
large amounts of fallen petals, dropped florets,
and yellowing leaves.
• Growers and wholesalers prevent this damage by
using ethylene inhibitors, which are products that
block or tie up the gas.
• They also strive to keep storage areas free of aging,
decaying plant materials.
Senescence
• Disease or damage shortens the life of
floral materials.
– Flowers that arrive from the market and those
picked in the garden should be of the highest
quality.
– They must be inspected for disease and insect
damage.
Maximizing Vase Life
• Conditioning plant materials includes a
number of steps.
• 1. Flowers should be unpacked and
inspected upon receipt.
– A report should be made to the wholesaler of
any problems or mistakes.
• 2. Prioritize the order of processing.
– Condition the wilt-prone and expensive flowers
first.
• 3. Remove sleeves, ties, and any foliage
that might contact water in a container.
Maximizing Vase Life
• 4. Under warm water, re-cut all stems,
removing ½ inch to 1 inch.
– Professional underwater cutting devices are
recommended.
• 5. Use specific
treatment solutions
as needed.
Maximizing Vase Life
• 6. Place in a floral preservative solution
mixed at the proper concentration.
– Too little encourages bacterial growth while too
much can cause toxicity.
• 7. Let the flowers remain at room
temperature for two to three hours to
increase water uptake.
• 8. Place the flowers in a cooler set at 34 to
38°F with a high humidity level and
constant light.
Maximizing Vase Life
• Flowers with milky stems, such as
poinsettias and poppies, should be treated
by quickly dipping them in boiling water for
five seconds and then placing them in a
floral preservative solution.
• Alternative methods include exposing the
cut end into a match flame without burning
it or placing it in very warm floral
preservative solution.
Maximizing Vase Life
• Roses that have lost turgidity near the
flower head are called bent necks.
• They can be revived by re-cutting the
stems under water and placing the entire
stems in a warm preservative solution.
Floral Preservatives
• Floral preservatives will extend the life of
cut flowers.
– A preservative contains a sugar as a
supplemental food source, an acidifier to
decrease the chance of stem clogging, and a
bactericide to kill bacteria in a vase or stem.
• Pre-treatments are used before
preservatives to reduce ethylene exposure
and to hydrate flowers that are wilt prone,
such as Gerbera and roses.
• All flowers can benefit from a hydrating
solution treatment.
From Field to Florist
• The majority of cut flowers sold in the
United States are produced in foreign
countries.
• The commercial packing and shipping
process affects the life span of cut flowers
in the floral market.
• First, flowers are graded or
separated into groups based
on factors such as quality,
uniformity, and size.
From Field to Florist
• They are also graded
by:
– stem quality
– Length
– strength
• The flowers are then
placed in bundles and
sleeved for shipping.
From Field to Florist
• After bundling, the flowers are boxed for
shipment and precooled…
– a method of quickly replacing the warm air with
cool air inside the box; this is also called being
dry packed.
• More delicate flowers, such as snapdragons
and gladioli are packed in hampers and
stored in an upright position.
• The largest amount of flowers are shipped
via air and then via truck to the
marketplace.
Review/Summary
•When a flower is cut, what are its
needs?
•What causes a flower to
deteriorate and die?
Review/Summary
•How are cut flowers and foliage
conditioned to maximize vase life?
•How does a floral preservative
extend the life of cut flowers?
Review/Summary
•How are flowers sent from the
field to the florist?