Gardening for Cut Flowers

Terry Brite DelValle

Horticulture Extension Agent Emeritus

Benefits of Gardening for Cut Flowers

• Eye candy – landscape

color

• Attracts pollinators,

hummingbirds and

beneficial insects

• Instant supply of cut

flowers to beautify the

home

Cut Flower Options

• Annuals

• Herbaceous Perennials

• Bulbs, corms, tubers, rhizomes

• Woody Plants

Succession Planting

• Single stem cuts

and o Every 2 weeks

• Flowers that get

smaller as season

progresseso Every 6 weeks

o Zinnias

Daylength SensitivityPhotoperiod

• Day-neutral: More versatile

and good for succession

planting / great for fall & spring

• Short days: < 12 hours

o Poinsettia, Salvia leucantha

/Mexican sage,

Chrysanthemum

• Long Days: > 12 hours

o Phlox paniculata

(midsummer), Alstroemeria

Growing Options• In-ground

o Loosen soil ~18” deep

• Containerso 2 gallon & bigger

o Bulb crates: line with newspaper, fill with potting soil... great for lilies & some other bulbs

• Raised beds

Soil Needs• Fertile, well-drained

sandy loam

• Neutral to slightly

acid soil pH

• Good organic

matter

oAdd compost

and other soil

amendments

Other needs…

• Access to water

• Irrigation system:

best to use drip

• Wind Protection:

fence or plant

windbreak or

protected side

of home

Support

• Select varieties with long,

stiff stems

• Netting with ~4” square

openings - place ~12-18”

high

• Tall stakes at corners,

then run twine along

perimeter of row or bed

• Individual plant stakes

Fertilization Options• Test soil for nutrients

and pH before planting

& adjust

• Slow/Quick Release

• Supplemental

fertilization similar to

vegetable gardening

• Foliar feed: dilute spray

of fish emulsion,

compost tea, etc.

before blooms present

Weed Control• Remove as soon

as they emerge

• Newspaper

• Mulches: pine straw, pine bark, oak leaves, etc.o Silver reflective

mulch repels some insects

Plant SpacingSunflowers: some are too

big for floral designs (8-

10” diameter)

• Tighter spacing will

reduce flower size

• 4 x 6” spacing will

reduce flower size to 4-

6” diameter flower

• Plant closer than in a

landscape bed

• Slightly crowded plants

grow taller, branch less plus

help hold each other up

• Depends on species

o Most annuals 9 x 9”

o Zinnias, stock, larkspur: 6 x 6”

o Gladiolus, liatris, allium: 4 x 4”

Pinching…

Snapdragons• No pinching = 1 longer

flower stem

• Pinching = multiple

flowers on shorter stems

• To increase yield and prolong blooms

• Soft pinch– removes growing tip and < 1” of stem; promotes multiple shoots that bloom at same time

• Hard pinch – removes several tiers of leaves and several inches of stem: used if plants are leggy/will delay flowering

Managing Pests/Diseases• Diseases

o Powdery mildew: cool

humid nights + dry hot

days (spores on both

sides of leaves + shoots,

buds & flowers; wind spreads spores;

overhead irrigation will

help control

o Downy mildew: cool, wet

weather (spores on

underside of leaves)

• Follow IPM practices:

sprays (soaps, etc.)

best before flowers

develop

o Crop rotation

o Sanitation

o Cultural practices to

encourage healthy

plants

o Select plants resistant to

diseases/pests

o Encourage beneficial

insects

Annuals to Use as Cuts• Gomphrena

• Hollyhock

• Lavender

• Marguerite Daisy

• Marigold

• Mexican sunflower (Tithonia)

• Pansy/Viola

• Penta

• Petunia

• Poinsettia

• Poppies

• Rudbeckia / Black-eyed Susan

• Scabiosa (Pincushion)

• Snapdragon

• Strawflower

• Sunflowers

• Sweetpeas

• Sunflower

• Zinnia

• Ageratum

• Amaranth

• Angelonia

• Asclepias

• Baby’s Breath

• Basil

• Bee Balm

• Blue daze

• Calendula

• Carnation

• Celosia

• Coreopsis

• Cosmos

• Delphinium/Larkspur

• Dianthus spp.

• Dill

• Foxglove

• Gaillardia

• Geranium

Direct Seed or Use Transplants

Transplants – some better

grown as transplants plus

helps you get a jump on

the season

May need to order seed

to grow specific varieties

Direct Seed

• Amaranthus spp.

• Celosia

• Cosmos

• Helianthus spp. /

Sunflower

• Scabiosa

• Marigolds

• Zinnia

Top Picks for cut flowers on Johnny’s Website

• Amaranth

• Snapdragon

• Strawflower

• Cosmos

• Scabiosa

• Gomphrena

• Sunflowers

• Zinnia

• Rudbeckia

• Celosia

• Basil

• Dill

• Ageratum

Antirrhinum majusSnapdragons

• Start seed indoors (cool

season)

• 6 hours or more sun

• Height: 18” to 30”

• Spacing: 9” to 12”

• Days to Bloom: 100-120

• Stake or flower support

netting helpful

• Cut when 1st few blooms on

bottom are open; 1st cut

almost at ground level;

remove bottom 2/3 of

foliage; 7-10 days vase life

• Exhibit phototropism

Favorite varieties:Maryland,

Potomac, Rocket strains

Celosia argentea / Celosia

• 24-36” warm season

• Cristata: cockscomb

crested types/brain

flower (Cramers

burgundy)

• Plumosa: feathery

(Pampas plume)

• Spicata: wheat

• Transplant or direct

seed

• Long flowering season

Consolida spp.Larkspur

• Cool season annual for

fresh cuts or dried flowers

• Plants need cool period

for shoot elongation &

flower initiation

• Fresh: cut when 2-5 basal

flowers open

• Drying: harvest when

most flowers open but

not dropping; air dry 10-

14 days

Euphorbia pulcherimaPoinsettia

• Plant in protected area

and away from

exposure to outside

lighting

• Cut stems to desired

lengths; remove lower

leaves

• Place in cool water for

30 minutes; discard and

replace with fresh

water

Helianthus annuusSunflower

• Start indoors or direct seed in the garden (warm season)

• 6 or more hours sun

• Height 36-72”; space 6” to 24” apart (more space=larger flowers); support needed

• Days to bloom 55 to 110

• Attracts pollinators, beneficial insects and songbirds

• Excellent cut flower: single stem (10-14 days) or branched (5-7 days)

• Harvest as petals lift off center• Succession Planting: every week

to 10 days

• Some are pollenless

Favorite single stem: ProCut and Sunrich

Favorite Branching: Moulin Rouge, Starburst Lemon Aura, Teddy Bear

Sunflowers

• Allelopathic: prevents

other seeds from

germinating

• Organic growers are

experimenting using

them as a spray that

acts as an herbicide

• Don’t plant seeds

around sunflowers

Matthiola incana / Stock• Great annual cut for

form, color & fragrance

• Cool temps for optimum

flowering; long days

before or during cool

treatment enhances

flowering

• Harvest when ½ flowers

open; immediately

place in floral

preservative & out of sun

Monarda hybridaBee Balm

▪ Start seed indoors or direct

seed (early spring)

▪ Mint family (can be weedy)

▪ Grows in sun and partial

shade; dry sandy soils

▪ 24-36” tall; spacing 6-12”

▪ Days to bloom: 70-80

▪ Harvest when lower flowers

develop color; 1st cut is low;

7 days for vase life

▪ ‘Lambada’ preferred variety

Lemon Beebalm

Rudbeckia spp.

• Heat & drought tolerant

• Best planted as

transplants

• 6 or more hours sun

• Size: 24-48” tall x 6-12”

• Days to bloom: 100-120

• Harvest when blooms are

halfway open

• 1st cut - almost at ground

level, just above 3 to 4

side shoots

Favorites: R. hirta ‘Indian Summer’, ‘Double Daisy’, ‘Goldilocks’, ‘Prairie Sun’ (photo above) powdery mildew may be a problemR. maxima ‘Giant’R. Triloba (Black-eyed Susan filler)

Tithonia rotundifolia

Mexican Sunflower• ‘Torch’ is best cut variety

• Warm season annual; start indoors or direct seed

• Space 24” apart; support needed

• 5-6’ tall; dwarf 3’ tall

• Full sun but will tolerate some shade

• Well drained but water during dry weather

• Harvest when flowers begin to open; cut low

• 5-7 days vase life

Zinnia elegans – 1 of Top 10• Start indoors or direct seed /

warm season

• 6 hours or more sun

• Height: 24” to 48”

• Spacing: 6” to 12”

• Days to Bloom: 60-75

• Stake or flower support netting helpful; wind helpful to reduce powdery mildew

• Cut when all flower petals open and a few stamens showing; 1st cut almost at ground level

• Succession sow every 6 weeks (flowers get smaller over time)

Favorites: Benary’s Giant, Uproar Rose, Queen Red Lime, Queen Lime

Green, Queen Lime Orange, Oklahoma, Giant Cactus, Zowie and

Cupcake

Add Herbs for Fragrance

• Basil: African blue basil, lemon basil, dark opal basil, cinnamon basil, ’Oriental Breeze’

• Rosemary

• Lavender

• Mints

• Dill

• Fennel

• Chives & garlic chives flowers

• Nasturtium – ‘Jewel’

Perennials to Use as Cuts• Kniphofia / red hot poker

• Lily of the Nile

• Lion’s Ear

• Louisiana Iris

• Penta

• Plumbago

• Salvias

• Shrimp Plant

• Stokesia / Stokes Aster

• Swamp Sunflower

• Yarrow

• Amaryllis

• Asclepias spp.

• Aster

• Bird of Paradise

• Black-eyed Susan

• Coneflower

• Daffodils

• Firespike

• Gaillardia

• Gerbera Daisy

• Gingers

• Goldenrod

• Jacobinia

Agapanthus africanusAfrican lily

• Evergreen with underground rhizome native to South Africa

• Plant Oct to Feb in FS (best) to PS, organic well-drained soil

• 1 ½’ tall plant with 2 ½’ tall blue, pink or white blooms in late spring to early summer

• Give moisture during summer months & protect from severe freezes; keep drier in winter

Amaryllis / Hippeastrum spp.

• Plant Sept to Jan with bulb tip @ soil level

• Spring bloomer assorted colors

• To force, no water for 2 months in winter

• Good in containers or hyacinth vase

• Red leaf blotch & chewing insects

Asclepias tuberosaButterfly Milkweed

• Native to eastern N.A.

• 1’ to 3’ high & wide

• Full sun, dry to medium moisture in well-drained soils

• Blooms late spring into summer

• Deep taproot so difficult to transplant

• Top dies back in winter

• Bee & butterfly nectar source and larval food for monarch, queen, soldier

• Harvest when ½ to 2/3 of flowers open

• Place in water ASAPchangein a few minutes & put in warm water – change again in a few hours

Getting milky sap in eyes can cause permanent damage

Curcuma spp. /

Hidden Ginger

• 1-8’ tall

• Related to Tumeric

• Flower time varies depending on type, basal or terminal

• PS to sun, moist

• Long lasting cut flower

Echinacea purpurea

Purple Coneflower

• Hardy perennial

• Full sun to part shade, well drained soil, drought tolerant

• Harvest just as petals start to unfurl

• Dried flowers: older flowers, remove petals and hang upside down

• New varieties: Sunset, Harvest Moon

Gladiolus• Michigan and Florida

are the main US producers

• Corms – produce flowers in 3 months from planting

• Plant 2” apart 4-5” deep

• Harvest when ½ flowers are open

• Negative geotropism

• Sensitive to fluorides in water

Iris virginicaSouthern blue flag

• Native to US zones

5-9

• 2’-3’ tall & wide

• Full sun to part

shade; moist to wet

boggy acidic soils;

rain and water

gardens / borders

of streams and

ponds

• Blooms late spring

Kniphofia uvaria / Tritoma

• Red Hot Poker

• Zones 5-10; from Africa

• Full sun, good drainage

• Long grass-like foliage

• Deer resistant; attracts hummers

Liatris spicata / Blazing Stars,

Gayfeathers

• Perennial or annual

wildflower; sandhills,

flatwoods and scrub

areas

• Full sun, moist to dry

acidic soils

• Flowers late summer to

fall; harvest when ½

flowers are open

Narcissus / Daffodil• Plant in Sept to Oct. in full sun

to partial shade; no artificial chilling

• Winter to spring bloomer

• Varieties in Duval Trialo Avalanche

o Bittern

o Bridal Crowno Carlton

o Campernielli N X Odorus

o Erlicheer

o Hawera

o Ice Follies

o Nonyo Saint Keverne

o Soleil d’Or

o Thalia

Carlton

Narcissus, Daffodil• Harvest when flower buds

at gooseneck stage –hanging at a 90⁰ angle or for smaller ones when starting to show color

• Pull it from stem base instead of cutting

• Keep in separate vase for at least 12 hours-then rinse stems before mixing with other flowers

• Do not add sugar to water – no benefit

• Flowers should last ~ a week

Strelitzia reginaeBird of Paradise

• Aka Gator flower

• 3-5’ tall clump, evergreen leaves, low maintenance

• FS-PS, fertile organic soil with good drainage

• Can produce blooms year-round

• Cut small slit along top; soak bud in warm water for 20 minutes; gently open sheath and lift flowers up and out

• Flowers can last up to 2 weeks as cut flowers

Rudbeckia laciniataCutleaf Coneflower

• Native herbaceous

perennial

• Organic soils with average

to medium moisture, needs

moisture in drought; full sun

to part shade but shade in

heat of day a plus

• Stays low to ground but up

to 8’ tall when in flower with

4’ spread

• Flowers late summer to fall;

cut flowers back to

encourage more blooms

Salvia spp.• Many different

species and

varieties, heights

and colors

• May only last for

3-5 days before

shedding flowers

• S. leucantha

(Mexican sage) &

‘Victoria’

S. mexicana ‘Compton’s Pride’

Compton’s

S. guaranitica ‘Black and Blue’

Solidago hybrids / Goldenrod• Upright perennial, 2-3’;

blooms summer-fall

• Pollinator, attracts

beneficials & butterflies,

food for wildlife

• S. sempervirens – Seaside

goldenrod, 3-4’ tall; moist

to dry sites, full sun

• Harvest when ~ ½ the

flowers are open

• True or false? Goldenrod is

responsible for hayfever…

Cultivars: ‘Golden Gate’‘Golden lime’

‘Praecox’‘Strahlenkrone’

‘Super’‘Tara’

‘Tara Gold’‘Toto’

‘Yellow Submarine’

Stokesia laevisStoke’s Aster

• Native, many cultivars

• Blooms spring through

fall / white, blue, lilac

• Good border plant /

1-2 feet tall

• Partial shade to full sun

• Good drainage a must

Tricyrtis lasiocarpusAmethyst toad lily

• Perennial in lily family with orchid-

like flowers native to Asia

• 2’- 3’ tall ground cover for part

sun to light shade; organic, rich

soils with even moisture

• Blooms fall into winter

Woody Ornamentals as Cuts• Experiment with plants in your

landscape

• Some may only last a few days

while others last a week or

longer

• Longevity depends on flower

stage

Callistemon citrinusRed Bottlebrush

• Tree or shrub, upright or weeping; dwarf varieties also; native to Australia

• 10-15’ tall; dwarf 3’tall by 5’ wide, evergreen, hardy to 20°F

• Blooms on and off spring-fall

• Moderately fertile, moist but well- drained soil; full sun best; moderate salt and drought tolerance

Callicarpa americana / Beautyberry

• 4-8’tall x 3-6’ wide

• Specimen plant, prune to create fullness

• Rich soils, full sun to partial shade

• Purple or white berries late summer to fall

• Harvest 6-12” branches when fruit colored; remove foliage if still on – can be messy if fruit falls off

Camellias –

sasanqua and

japonica

Using Camellias as Cuts

• Cut stems

• Floating in

water

• Place grape

on cut end

Cephalanthus occidentalis /

Buttonbush• Native to swamps,

marshes and edges of

ponds and ditchbanks

• Full sun to partial

shade, moist to wet

sites, not drought

tolerant

• Fragrant flowers in

summer

Redbud – Cercis canadensis•20-30’ tall – late winter bloomer

•Round, medium growth

•Low salt tolerance, full sun to partial shade, drought tolerant; rich woodlands

Hibiscus spp.

• Woody shrub or perennial

• 4-12’ tall with 3 to 10’ spread

• Full sun best, medium drought tolerance; cold damage possible

• Blooms in spring through summer

• Most flowers only last a day; harvest in early morning; option refrigerate and bring out for evening occasion; no water needed

Hydrangea macrophyllaBigleaf Hydrangea

▪ Grow in partial shade or morning sun

▪ Add organic matter; water at base

▪ Harvest blooms that are completely open in early morning with 18-30” stem length; remove leaves & place in hot water (110-120⁰F) & put in cooler for 8 hours; if they wilt, place in heated water Best one for drying

Hydrangea quercifolia

Oakleaf Hydrangea

• Native deciduous shrub used as specimen or mass planting, background

• 4 to 8’ tall w/matching spread

• Full to part sun; rich acid, moist but well drained soils

• Exfoliating bark

Roses

• Direct sunlight for at least 6 hours per day and good air flow

• Well-drained soil, add organic matter

• Easier to grow types: old garden roses and shrub roses

• Growing Roses in Florida: http://edis.ifas.ufl.edu/ep339

Cramoisi Superieur (top)Old Blush (bottom)

Removing ThornsTrue or False

Dulling and removing

thorns on roses doesn’t

shorten vase life

False: Tampering with

thorns most often shortens

vase life because it

creates wounds allowing

microbes to enter which

can plug cells

Harvesting: Start With Clean Containers

• Wash buckets and

vases with a few

drops of liquid dish

detergent and 1 tsp

bleach/gallon of

water removing any

debris

• Rinse to remove

bleach

Clippers• Use a good quality pair of

shears; type will depend

on size of stem

• Never use scissors

• Clean debris and sterilize

using similar solution for

cleaning vases

• Get sharpening stone to

keep blades sharp

• One reference prefers

Felco brand but also likes

Victorinox Flower

Gatherer for taller flowers

Water Quality

• May need to acidify water: alkaline water will not move up the stem (3.5 to 5.5 best) & helps to decrease bacteria

• Avoid waters high in salt

• Avoid water softeners (Na)

• Fluoride – some plants sensitive (glads, gerberas, freesias); let bucket of water sit for several hours at room temperature

General Tips

Timing depends on

species

• Lilies: cut when bottom

2 buds swollen and

showing color

• Iris: cut in pencil stage

showing a pencil-thin

streak of color

• Yarrow: harvest after

pollen appears or it will

wilt

• Harvest Often: once

or twice/week to

keep productive

• Where to make cut

and at what stage

depends on plant

• Best time is early

morning once dew

has dried

General Tips for Cut Flowers• Place cuts in clean container

with cool water ASAP

• Most flowers benefit from water with floral preservative

• Remove leaves that will be below the water line

• Before arranging, make fresh cut 1” to 2” above original under water @ 45 degree angle

• Best in cool spot with no direct light; avoid vents/fruit/cigarette smoke

• Change water every day; recut stems if needed

Cut Flower CareThe safest way to go is to

use commercial cut flower

foods

• controls microbial

populations

• provides sugars

• Lowers pH

Removing AnthersTrue or False

Removing the anthers

from lilies, amaryllis and

Alstroemerias affects vase

life

False: removing anthers

has no impact on vase

life but doing so might

prevent pollen stains

Best Way to Remove Pollen from Fabrics

• Brush away with soft dry

cloth or brush… use

anything but your hand

because skin oils set

pollen stains

• Use tape to remove

pollen grains

• Place stained fabric in

sunlight and it is

supposed to disappear

Do it Yourself Preservatives

Reference:

https://ag.umass.edu/prin

t/9403

• Sugars: needed if flower is harvested at a tight-bud stage. 1% sugar solution=2 level tspssugar/quart of H2O

• Biocide: household bleach or Physan. Using medicine dropper, add 1 ml of bleach or 0.5 ml Physan to quart of H2O

• Acid: Citric Acid to lower pH to 3.5 (varies –try fresh lime or lemon juice and test)

Another Option to Preserve Flowers

Refrigerator is great

option

• Tropicals (Proteas,

Anthuriums, gingers,

birds-of-paradise): 50-

55ºF

• Non tropicals: 33 to

35ºF

• Keep away from

ripening fruit

Stripping LeavesTrue or False

It doesn’t matter how much foliage you remove from fresh stems as long as none is below the water line

False: always remove leaves below water line plus broken/damaged leaves but keep as many leaves above water line as possible

Resources

• Specialty Cut Flowers, Allan Armitage & Judy Laushman, 2nd edition.

• The Flower Farmer, An Organic Grower’s Guide, Lynn Byczyniski

• Vegetables Love Flowers, by Lisa Mason Ziegler

• De-myth-tifying cut flower care: Dr. Terril A Nell, Florists’Review June 2004

• Various websites• Trial and Error ☺

Association of Specialty Cut Flower Growers

• www.ascfg.org

• ASCFG Conference and Trade Show November 9,

2020 in Orlando Florida