Transcript Roses in South Florida? - St. Lucie County Extension Office

Roses in South Florida?
Presented by:
Doug Heighton
St. Lucie County Master Gardener
St. Lucie County Cooperative Extension
8400 Picos Road, Suite 101
Fort Pierce, Florida 34945
Tel: 772-462-1660
Website: http://stlucie.ifas.ufl.edu
History of a Florida Rose
• Fortuniana rootstock, (also known as
Double Cherokee) is the rootstock of choice
for a South Florida garden.
• It was discovered in Ninghpo, China by
Robert Fortune around 1848.
• It offered a superior rootstock and
hardiness, necessary for our nematode
infested soils and our pests and diseases.
• Mrs. B.F. Lampkin of Sarasota, Florida
collaborated with Dr. Samuel McFadden, an
ornamental horticulturist from the
University of Florida.
• Dr. McFadden’s tests discovered that Rosa
fortuniana passed on great vigor to even
weak varieties.
• The rootstock was very heat tolerant, but
sensitive to the cold.
• It is more resistant to gall, stem die-back
and root diseases.
• It will live and produce longer than any
other rootstock.
• Some roses planted 40 years ago in Central
Florida are now the size of trees!
• Other rootstocks last approximately two
years before they decline and die.
• Fortuniana rootstock does well in all soils,
except heavy clay. It will survive freezing
temperatures if allowed to acclimate.
• Rosarians all over the South are growing
roses on Fortuniana rootstock.
Selecting Rose Cultivars
• Old Roses, Old-fashioned Roses, Antique Roses
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Existed before 1867
Once blooming, an occasional repeat bloomer
More disease-resistant, less maintenance
Albas, Bourbons, Boursaults, Centifolias, Chinas,
Damasks, Gallicas, Hybrid Perpetuals, Mosses,
Noisettes, Portlands, and Tea roses.
• Modern Roses: Hybrid Tea, Floribunda and
Grandiflora Roses
• Hybrid Tea
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1st hybrid tea, “La France” bred in 1867
The most popular class of roses
Large flowers with a high-pointed bud
Repeat bloomers, blooming almost continually
One flower per stem on long sturdy stems –
excellent for cutting
– Large variety of colors
– Upright shrubs
MISTER LINCOLN
OLYMPIAD
• Floribunda
– Created around 1909 by crossing Polyanthus with
Hybrid Teas.
– Low growing bush with flowers produced in clusters
– Usually more and smaller flowers on shorter stems
– Well suited for landscape plants. They are often used
for living hedges, borders, foundation covers, and to
create mounds of color in the garden.
– They tend to re-bloom faster than the
average Hybrid Tea, are somewhat
hardier, and put up with a lot of neglect.
– They bloom throughout the season,
with heavy sprays of richly
colored blooms.
EUROPEANA
• Grandiflora
– The Grandiflora a cross of 'Charlotte Armstrong', a
Hybrid Tea, and 'Floradora', a Floribunda. This rose is
representative of the attempts at that time to produce a
"different" rose (a mere 100 years after the first Hybrid
Tea appeared) that would have the characteristic long
stems, large beautiful blooms and pointed buds of the
Hybrid Teas with the hardiness and flower clusters of
the shrubbier Floribundas.
– Grandifloras have a tendency to grow
quite tall and produce full, large flowers.
They come one to a stem as well as in
clusters. The gangly growth habit is
reminiscent of their Tea heritage. The
individual florets are larger than the
standard for Floribundas yet not usually
as large as the huge blooms of the Hybrid Teas.
HEART OF GOLD
• English Rose, David Austin Roses
– Introduced in 1969 by David Austin of
England.
– An attempt to combine the best traits of Old
Roses and Modern Roses – classic flower forms
and fragrance of Old Roses on plants that repeat
bloom like Modern Roses.
• Miniatures
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Diminutive forms of other roses
Originally derived from China roses
Grows from 6” to 18” in height
Quite hardy and can be grown in containers
INA
• Climber
– This rose is hybridized to sprawl and must be
trained to “climb” where you want them to.
– Whatever pattern you create, be sure to tie
down the tips encouraging blooms along the
climbers arching canes.
AMERICA
• Standard
– Tree roses or standards are bushes that bloom
atop a length of rosewood that has no growth
along its sides.
– They have two bud unions
separated by a length of rosewood.
– A hybrid is grafted to the top and
rootstock to the base.
Where do we plant them?
• Roses prefer full sun, a
minimum of 6 hours
• Morning sun is very
helpful for it dries the
leaves
• Group roses together
• Prepare a special welldrained area (raised beds)
& add organics
• Moderately acidic soil
(pH 5.5 to 6.5)
What are these Amendments
• Pre-planting soil
amendments improve
water holding capacity,
the nutrient balance and
change the soil reaction
(pH)
• Organics to use are:
compost, leaf mold, peat,
muck, sawdust, wood
shavings and manures –
use a 4” combined layer
and mix thoroughly into a
12” depth of soil
Maintenance
• Irrigate during dry or
months of drought
• 1 inch of water each
week unless similar
rainfall.
• Water the day before
spraying pesticide
• Apply water the the
soil surface not the
plant surface
• Use a complete fertilizer
with a ratio of 3-1-2
• Fertilizer should be
applied to plantings ~7
times per year (each time
plants produce a flush of
bloom)
• Secondary plant foods
can be supplied by
organic or inorganic
materials.
• Use slow release
• Check for deficiencies
• Mulch with a 2-3”
organic soil covering
2” away from the stem
• Mulch reduces
weeding and soil
moisture loss and
provides some
nutrients to the plants
• Use compost, wood
chips, pine needles,
sugarcane bagasse or
other natural materials
• Pruning
– Remove suckers that develop from the rootstock below
the graft by breaking them off, thereby removing all
basal buds
– Remove dead wood and canes showing stem disease
symptoms when first noticed. Cut back to healthy
wood and remove affected part from the garden
– Major yearly pruning should be done in March and late
August to avoid interrupting winter flowering
– To avoid dieback and encourage rapid healing, pruning
cuts should be made just above a dormant bud eye
Pests
• Spider mites are tiny
arachnids that feel like dust
under the leaf.
• They occur during hot, dry
weather
• They can be controlled by
spraying soapy water every
7-10 days to knock down
the webs
• Spray undersides of leaves
• May need to use a miticide
SPIDER MITES
• Aphids are tiny insects
about 1/16 – 1/8 inch,
green, red or black
• They damage tender new
growth
• A hard spray of water or
soap solution will remove
aphid infestations. They
reproduce every 7 days,
treatments will need to be
repeated
• Ants have a mutual
relationship with aphids
APHIDS
THRIPS
• Thrips are tiny insects
that do cosmetic
damage to roses by
ruining the bloom
• They may prevent a
bloom from opening
or cause discoloration
of the flower
• Thrips prefer light
colored flowers
• Control with systemic
insecticide
SOOTY MOLD
• Sooty mold is a fungus
that develops on the
sweet honeydew
excrement from
sucking insects.
• The insects that cause
the secretion are
located above the
sooty mold
• It is not harmful – but
it is unsightly
BLACKSPOT
• Blackspot is a fungus that
causes black spots about
1/16 to 1/2 inch in
diameter to form on the
leaves
• The infected leaves later
turn yellow around the
spots and eventually fall
from the plant
• Conditions promoting
blackspot are wet leaves,
splashing water and warm
temperatures
• Preventing Blackspot
– Water soil not leaves
– Remove all diseased leaves
– Prune away crossing canes, open center of
plant, allowing for air to circulate
– Mulch well to minimize water splashing
– A weak or stressed plant is more susceptible to
disease
– Alternate fungicides between systemic and
contact or use a mixture of soap and oil
• Powdery Mildew
forms a white or
grayish coating on the
upper surface of
young leaves and buds
• Infected leaves
crumple and become
distorted
• It thrives during high
humidity but forms on
dry leaves
• Keep areas airy
POWERY MILDEW
ANTRACNOSE
• Anthracnose is a disease
that is seen when cool,
moist and humid
conditions exist.
• Anthracnose can be
prevented by using a
fungicide, but once the
leaves are infected
spraying won't do any
good. Fungicides are
effective in preventing
disease infection but will
not stop the disease once it
has infected the leaves.
MOSAIC VIRUS
• Mosaic Virus causes
interesting yellow patterns
to form on some of the
otherwise healthy leaves
of the plant
• Mosaic Virus can not be
transmitted from one plant
to another through pruning
• It can be transmitted by
grafting a healthy rose
onto virused rootstock
• Plants with a virus will
live, but will not be as
thrifty
Key Points to Growing Roses
• Location – minimum 6 hours of sun
• Plant roses that have been grafted onto Rosa
fortuniana rootstock
• Select a rose variety based on care required
• Weekly maintenance is necessary for
disease and pest control
• Proper pruning ensures the lasting beauty of
your roses
Low Maintenance Evaluation
• In 2008 a study was initiated by UF/IFAS to
determine how 12 different roses would
perform under identical low maintenance
conditions in Fort Pierce, Plant City and
Quincy.
• After two years the Bermuda ‘Spice’ rose
and Knockout ‘Radrazz’ rose performed
best in Fort Pierce.
Bermuda ‘Spice’ Rose
Knockout ‘Radrazz’ Rose
See presentation material in American Society for Horticulture Science
(ASHS) paper, 2010
http://ashs.confex.com/ashs/2010/webprogram/paper4162.html
Thank you!