This is a glossary or dictionary
of rose-related terms. It can be useful as a quick reference
for rose questions.
TOPICS
Abbreviations:
Here are some commonly used abbreviations used when discussing
roses:
ARE - Antique Rose Emporium (mail-order nursery)
ARS - American Rose Society
DAs or ER - David Austin Roses or English Roses
FB or FL - Floribunda
HT - Hybrid Tea
J&P - Jackson and Perkins (mail-order nursery)
Min - Miniature
OGR - Old Garden Rose
RYT - Roses of Yesterday and Today (mail-order nursery)
Aphids:
Aphids are tiny insects about a 1/16
to 1/8 inches long, usually light green, red or black. They
come in the spring and damage tender new growth. A hard spray
of water from the hose will help remove aphid infestations.
Aphids reproduce quickly and this may need to be repeated
every couple days for a couple weeks. Aphids have a mutually
beneficial relationship with ants, so ants need to be controlled
if aphids are to be controlled. Ladybugs are a natural predator
of aphids and can be used to control aphids. If ladybugs are
purchased, water the area well and release the ladybugs around
sunset to discourage them from leaving.
Black roses:
No true black roses exist. Some roses
sold as black roses are actually dark red or maroon. The petals
of many of these dark red roses tend to sunburn easily. To
see that a rose is not truly black, hold it up next to a piece
of black construction paper. To make a dark red rose appear
blacker, put its stem in water that has black ink in it. Below
is an incomplete list of some roses that have been mentioned
when black roses are discussed. Next to some of the roses
a very subjective description of the color is given.
Black Jade: dark
red miniature
Cardinal de Richelieu:
dark purple
Gallica Chateau de Clos-Vougeot:
HT, deep red blossoms, blackish highlights, poor growth Francis
Dubreuil: Tea rose
Guinee:
very, very dark red
Ink Spots:
Mr. Lincoln:
HT, dark red
Nuits de Young:
purple Moss rose
Oklahoma: HT,
deep crimson
Souvenir du Dr Jamain:
Hybrid Perpetual, dark red/maroon
Sympathie:
deep red climber
Taboo:
Popular dark rose that has deep red flowers with darker edges.
It reportedly has nearly black buds
The Prince:
English rose, very, very dark red/purple
Tuscany Superb:
Gallica, deep maroon velvet
Blackspot:
Blackspot is a fungus that causes black
spots about 1/16 to 1/2 inches in diameter to form on the
leaves and sometimes stems. The infected leaves later turn
yellow around the spots and eventually fall from the plant.
In bad cases, blackspot can severely defoliate a rose bush.
The conditions that promote blackspot are wet leaves, splashing
water and warm temperatures. Here are some ways to combat
blackspot. Most of these methods also apply to preventing
and treating powdery mildew.
1.
Pick a variety of rose resistant to blackspot. For example,
many Rugosas are quite resistant to blackspot.
2.
Use watering methods that don't get the leaves wet: drip watering,
using a soaker hose, or just soaking the ground with a light
stream from a garden hose. If overhead watering is used, do
so in the morning so the leaves can dry off before evening.
3.
Remove ALL diseased leaves from the plant or ground immediately
to prevent further spreading of the disease. Infected leaves
never get better, they just spread the disease. Prune infected
canes severely in late winter.
4. Prune
away crossing canes and open the center of the bush to allow
sunlight and airflow to more of the plant.
5.
Blackspot is transmitted by water splash. Remove leaves close
to the ground (the first 6-8 inches) which are more susceptible
to getting water splashed on them. Mulch well to minimize
water splashing onto leaves. If a plant had a lot of blackspot
the previous year, remove the old mulch in early Spring, allow
the area to dry and replace with clean new mulch.
6.
Keep the plant well watered. A weak or stressed plant is more
susceptible to disease.
Preventative spray treatments for
blackspot
1.
Chemical fungicides can be very effective in preventing blackspot
and are usually applied every 7-14 days. It is most important
to spray the undersides of the leaves. FOLLOW THE LABEL DIRECTIONS
EXACTLY. Too much fungicide can cause leaf burn. It is best
if rose plants are watered well before spraying. Spraying
during very hot weather can damage leaves. Early morning and
early evening are the best times to spray. Avoid spraying
under windy conditions. READ THE PRODUCT LABEL carefully and
wear proper equipment when spraying, such as eye, mouth and
nose protection.
2.
Since a single fungicide may not completely wipe out all the
fungi, using that fungicide over and over may actually cause
fungus to build up a resistance to that fungicide. Alternating
between two fungicides, such as Triforine (Funginex) and Daconil,
is recommended to keep resistant fungi from building up. Fungicides
generally can prevent blackspot, but do not cure an existing
case of blackspot.
3. Some
gardeners wishing to avoid fungicide use have tried using
baking soda to help prevent blackspot with mixed results.
Combine 1 1/2 tablespoon baking soda and either 2 tablespoons
horticultural oil or a few drops of Ivory liquid with 1 gallon
of water. Mix as well as possible, and spray both sides of
the leaves once a week. The Ivory liquid helps the baking
soda stick to the leaves. Reapply after a rain. Baking soda
changes the P.H. of the leaves, helping to prevent blackspot.
Spraying with baking soda works for some gardeners, but others
have found that baking soda is not effective enough in their
climate.
Blue roses:
Though highly sought after, no blue
roses exist yet. Some roses are advertised as blue, but they
are actually lavender or something. Most lavender roses are
difficult to grow and are quite susceptible to disease.
Some of the bluer roses are:
Blue Girl, Blue Jay(HT), and Reine des
Violettes(HP). A couple of true purple roses are Cardinal
de Richelieu and Veilchenblau. The genetics are just not there
for producing a true blue color in roses. It will probably
be necessary to use gene splicing to produce the first blue
rose.
Borers:
Borers can enter the cane through the
pruned tops. Prevented by sealing the canes with wax, white
glue, or nail polish.
Bud-pinching:
When a Floribunda forms a bloom "spike"
or "candelabra" - it is setting many little blooms
on one stem. To prune Floribundas for quality of bloom, rather
than the maximum number of blooms, pinch out the center, fat
bud so the side buds have a better chance at developing at
the same time. This encourages a big rounded mass of blossoms
- a "spray." Floribundas like to do this so it is
relatively easy to persuade them to flower in this manner.
Once some of the blooms begin to fade, you can just cut out
the few that are dying and let the spray continue to develop
blooms. Once the entire spray is spent, or most of the individually
blooms are finished, cut off the entire spray.
Cut roses:
Cut flowers in early morning or after
it rains, not when they are under water stress. Cut the stem
about an inch longer than you need. After cutting, immediately
place cut flower in warm water. If possible, with the stem
under water, cut off the bottom inch or so of the stem at
an angle. This keeps air from getting into the stem. Remove
all foliage that remains under water and would just rot. Recut
the stem underwater every day if possible. Some people add
a small amount of bleach to the water to keep down fungus
and bacteria. Sugar or soda can be used for food. Others use
a commercial floral preservative.
David
Austin Roses:
see English Roses:
Deadheading:
(see also hips: ) Deadheading is cutting
off flowers as they wither or don't look as good. Old blooms
left on the plant may have been pollinated and may begin to
form seed pods (hips). The formation of hips requires a lot
of energy from the plant and slows flower production. By preventing
the formation of hips, deadheading encourages the rose bush
to grow new flowers. The choice of which spot to deadhead
at is influenced by what shape you want the bush to take,
and which direction you want a particular cane to grow. Usually,
you will want to cut the stem at a 45-degree angle just above
an outward-facing leaf. Make sure the high side of the cut
is the side the leaf set is on. To deadhead, remove the flower
by making a diagonal cut just above the next 5 or 7-leaf branch
down on the stem. The idea is to cut to a bud eye capable
of producing a healthy cane. If this would cause too much
of the cane to be removed, a 3-leaf branch can be chosen instead.
The first year cut back to the first 3 or 5-leaf branch. In
following years cut far enough down to get to a 5-leaf branch
with a leaf bud that is facing outward. This will open up
the plant. Once blooming roses do not need to be deadheaded.
They bloom once and then they are finished blooming for the
year. However, once-blooming roses may be (in fact, should
be) pruned after they are finished blooming. They should NOT
be pruned in the fall or before they bloom because they bloom
on the previous year's growth. Stop deadheading as of September
1 in zones 4 and 5. It is a good practice to let the last
roses on HT's produce hips because it makes them more frost
hardy. It causes the plant to undergo chemical changes that
slow down growth, inhibit blooming and generally prepare for
dormancy by focusing its energy on 'hardening' the canes.
The formation of hips tells the plant that it's "done
its job" and can now rest from its labors.
English
Roses:
( abbr. ER, see also Modern Roses: ,
Old Roses: ) This new group of roses, often called David Austin
Roses, was introduced in 1969 by David Austin of England.
These roses are an attempt to combine the best traits of both
Old Roses and Modern Roses. David Austin has attempted to
produce roses with the classic flower forms and fragrance
of the Old Roses on plants that repeat bloom like the Modern
Roses. Some of the popular English Roses are Abraham Darby,
Graham Thomas, Heritage, and Mary Rose.
Fertilizer:
Roses will perform much better if given
adequate fertilizer. Use a well balanced fertilizer, such
as 10-10-10, N-P-K. The three numbers used to describe a fertilizer
tell how much of the three major nutrients are in that fertilizer.
The first number (N)
is the Nitrogen content,
the second (P)
is Phosphorous,
and the third (K)
is Potassium.
Nitrogen or Nitrogen-Phosphorous-Potassium, (leaves,flowers,roots).
Fertilize less during the first year while the plant is getting
established. When planting roses, it is recommended that you
add long-term sources of Phosphorous and Potassium to the
soil near the roots because these two elements move slowly
through the soil. Bone meal and rock phosphate are good long-term
sources of Phosphorous. Granite sand is a long-term source
of Potassium. Cottonseed meal (lowers soil P.H.), alfalfa
meal, and blood meal are organic sources of Nitrogen. Alfalfa
meal also releases a growth stimulator as it decomposes. Many
forms of inorganic Nitrogen leach quickly from the soil. Nitrogen
also helps stimulate basal breaks. Some rose growers fertilize
with Epsom salts. Epsom salts are magnesium sulfate, a source
of Magnesium. Being a sulfate, it will lower soil P.H. Although
the need to use of Epsom salts is frequently debated, Magnesium
(along with Nitrogen) is supposed to stimulate basal breaks.
Many gardeners use 1/4 cup of Epsom salts per plant in the
Spring and/or Fall. Some use as little as 1 tablespoon per
plant, others up to 1/2 cup. Seaweed is a good organic source
of trace elements.
Floribundas:
(abbr. FB or FL) Floribundas were created
about 1909 by crossing the Polyanthas with Hybrid Teas. They
produce flowers in clusters, not singly like the Hybrid Teas.
Floribundas are usually shorter plants than Hybrid Teas and
tend to produce more flowers and smaller flowers than Hybrid
Teas on shorter stems. Although Hybrid Teas provide excellent
cut flowers, Floribundas are well suited as good landscape
plants providing lots of color. Many Floribundas are not very
fragrant. When a Floribunda forms a bloom "spike"
or "candelabra" - it is setting many little blooms
on one stem. To prune Floribundas for quality of bloom, rather
than the maximum number of blooms, pinch out the center, fat
bud so the side buds have a better chance at developing at
the same time. This encourages a big rounded mass of blossoms
- a "spray." Floribundas like to do this so it is
relatively easy to persuade them to flower in this manner.
Once some of the blooms begin to fade, you can just cut out
the few that are dying and let the spray continue to develop
blooms. Once the entire spray is spent, or most of the individually
blooms are finished, cut off the entire spray.
Fragrance:
Fragrance contributes much to the enjoyment
of roses. It is also one of the most subjective of topics
when discussing roses. Fragrance or perceived fragrance depends
upon many factors: variety of rose, time of day, weather,
growing conditions, the person smelling the rose, living flower
vs. cut flower, etc. Each person's sense of smell is different.
A rose that is very fragrant to someone, may be not at all
fragrant to someone else. Roses are most fragrant around mid-morning
on a warm day with no wind and moderate or high humidity.
There are dozens of components in the fragrance of a rose,
but rose scents are usually categorized with such descriptions
as "spicy", "tea", "old rose",
or "fruity". Here is a list of some very fragrant
roses.
Double Delight (mentioned most often),
spicy, red-white bicolor
Fragrant Cloud, reddish-orange
Mr. Lincoln, dark red
Crimson Glory, red
Chrysler Imperial, red
Papa Meilland, dark red
Perfume Delight, pink
Secret
Gertrude Jekyll, pink
Othello, dark red
Alba: Felicite Parmentier, once-blooming
Damask: Mme. Hardy, white, once-blooming
Tea: Sombreuil, cream-white
Bourbon: Souvenir de la Malmasion
Souvenir du Dr Jamain
Many of the David Austin roses are fragrant.
So are many of the Old Roses, such as the Damasks.
Fungus:
Blackspot, powdery mildew and rust are
the three most common fungus problems that roses have. See
blackspot
for some ways of preventing and treating fungus problems.
Planting disease-resistant roses in a sunny location with
good air circulation will help prevent fungi.
Hips:
(see also deadheading: ) These are the
rose seed pods that form after a flower's petals fall if the
bloom was pollinated. Hips are the fruit produced by rose
plants. Apple trees are members of the rosacae family and
the apple is a hip. Some varieties such as R.rugosa produce
large hips that turn brilliant colors in the fall. Allowing
the hips to develop will cause a rose to slow down or stop
producing flowers. It also helps induce dormancy, helping
prepare the rose plant for winter in colder climates. In contrast,
deadheading will keep the plant from producing hips and encourage
it to produce more flowers.
Hybrid
Teas:
(abbr. HT) Hybrid Teas are easily the
most popular class of roses today. Hybrid Teas as a group
have large flowers with a high-pointed bud. They are excellent
repeat bloomers, often blooming almost continually. They bloom
one flower per stem on long sturdy stems making them excellent
for cutting. Hybrid Teas come in a large variety of colors.
Hybrid Teas are upright shrubs. The rose "La France",
bred in 1867, is classified as the first Hybrid Tea rose.
Japanese
Beetles:
A shiny copper green beetle that can
eat entire flowers as well as foliage. Can be controlled by
milky spore. leaf cutters: Leaf cutter bees cut semi-circle
shaped holes in the leaves of roses. They pose no real threat
to rose health, but they drive exhibitors crazy.
Mildew:
see powdery mildew:
Miniature
roses:
Miniature roses grow to only about 6"-18".
The plants, leaves are all miniatures of the larger roses.
Miniature roses tend to be quite hardy and can be grown in
containers.
Mites:
Spider mites are a tiny arachnid that
appear like dust under the leaves. They occur during hot,
dry weather. They can be controlled by spraying the plant
every 7-10 days with water to destroy the webs and knock the
mites off the leaves. Be sure to thoroughly cover the underside
of the lower leaves. They can also be controlled with the
miticides Avid or Kelthane.
Modern
Roses:
Refers to roses introduced since 1867
when the first Hybrid Tea was created. Usually refers to Hybrid
Tea, Floribunda, or Grandiflora roses. mosaic virus: see virus:
Mulch:
Roses benefit from a 2-3 inch
deep organic mulch such as pine bark, pine needles, leaf mulch,
etc. Keep the mulch a few inches away from the stem of the
plant.
Benefits of proper mulching:
1. Reduced watering requirements and
less water stress due to milder soil temperatures and reduced
evaporation.
2. Less disease from water splashing
on the lower leaves of plant.
3. Fewer weeds because the mulch blocks
some of the sunlight to weed seedlings.
4. Better soil as the mulch breaks down
and adds organic matter to the top layer of soil.
5. Good soil structure because mulch will help stop soil compaction.
Old Roses:
Sometimes called Old Roses, Old-fashioned
Roses or Antique Roses, these are the varieties of roses that
existed before 1867 when the first Hybrid Tea was introduced.
Some of the classes of Old Roses are the Albas, Bourbons,
Boursaults, Centifolias, Chinas, Damasks, Gallicas, Hybrid
Perpetuals, Mosses, Noisettes, Portlands, and Tea roses. Some
of the Ramblers and Rugosas are considered Old Roses. As a
group, Old Roses tend to be once blooming, though some are
repeat bloomers. They tend to be more disease-resistant and
require less maintenance than the Hybrid Teas which accounts
for some of their popularity. There are exceptions to this,
especially the China and Tea roses. The China and Tea roses
are tender and disease prone, but are very important because
they provide the repeat blooming genes to many classes of
roses (notably Hybrid Teas).
Once blooming:
(see also repeat blooming: ) Roses that bloom once a year,
usually in the spring. Since, they bloom only once a year,
when they do bloom they usually put on an excellent show.
They flower on old wood, so most pruning is done just after
they have finished blooming, not in the winter.
Own-root
roses:
An own-root rose is a plant whose rootstock
(the roots) is the same variety as the top of the plant. Grafted
roses, commonly referred to as budded plants, are plants where
the desired rose is grafted or budded onto a rootstock of
a different type. The point where the desired variety and
the rootstock meet is called the bud union. Own-root roses
are usually recommended for those in very cold climates. This
is because an own-root rose that dies back to the ground during
the winter can grow back the next year from the roots. If
a grafted rose dies back to the ground, what will come up
next Spring is the rootstock variety, usually an undesirable
variety of rose. Even if a rose doesn't die back to the ground.
Sometimes a shoot will emerge from the rootstock. If the rose
is grafted, this shoot is called a sucker, and will be the
same variety of the rootstock, not the desired plant. When
this happens with own-root roses, the shoot will be of the
desired variety. New canes can emerge each year from the bud
union of grafted roses. After many years, the bud union of
grafted roses can become large and knobby and eventually run
out of places for new canes to emerge from. This is not a
problem for own-root roses, since they lack the knobby bud
union of grafted roses. Therefore, grafted roses may not last
as long as own-root roses. Most roses are sold as grafted
plants, since it is more economical than selling own-root
plants. A common rootstock is "Dr. Huey", used by
J&P and Roses of Yesterday and Today and other nurseries
in the western US. It does well in alkaline soils. "Dr.
Huey" has a dark red bloom about 2 1/2 inches in diameter.
R. multiflora is commonly is in the eastern US. It prefers
acid soil. Wayside uses "Manetti" rootstock. There
has recently been some discussion about R. fortuniana rootstock.
It is primarily used in Florida where its root knot nematode
resistance is important. Its fine, spreading root network
is good for sandy soils. It is not considered to be freeze
hardy, so it is only recommended for mild climates. Don't
confuse own-root roses with bare-root roses, the terms refer
to different things. Roses are usually sold either bare-root
(no soil around the roots) or potted in containers. Bare-root
roses can be either own-root or grafted. Bare-root roses tend
to be less expensive than potted roses. Since they are lighter
(no soil) than potted roses, most mail-order roses are bare-root.
Patented
roses:
A rose variety may be patented just like
any other plant. A patent grants to the holder exclusive rights
to distribute and propagate that variety of rose. Of course
the patent holder can license others to distribute and propagate
that rose. A patent lasts for 17 years, so most older roses
aren't currently under patent. After the patent has expired,
anyone can distribute and propagate that particular variety.
Some nurseries divide their roses into patented roses and
non-patented roses, with the patented roses costing more.
This is because they may freely propagate the non-patented
varieties, but their is usually a fee for propagating patented
varieties. It is illegal to asexually reproduce a patented
plant, even for personal use. It is, however, legal to use
a patented rose in hybridizing.
Peace:
Peace is the most popular rose in the
world. It is a Hybrid Tea that was smuggled out of France
just before the Nazi occupation and introduced just after
the end of the World War II. It produces large blooms of yellow
blending to pink on the edges. It is not very fragrant. planting:
Bare-root: Roses that are shipped in their dormant state with
no foliage. Bare-root roses are planted during Winter or very-early
Spring. Container grown: Nurseries will often take bare-root
roses from the rose growers and place them in containers.
Container grown roses can be planted any time of the year
although it is better to plant when temperatures are moderate,
usually Spring or Fall.
Powdery
mildew:
This fungus forms a powdery white or
grayish coating on the upper surface of young leaves and sometimes
on the buds. Infected leaves crumple and become distorted.
Unlike blackspot, wet conditions actually inhibit the development
of powdery mildew. It can not reproduce in water. It thrives
during high humidity but forms on dry leaves. Warm dry days,
cool dry nights are ideal for powdery mildew. One of the best
ways to avoid powdery mildew is to keep things as airy as
possible. Roses planted too close to a wall may not get enough
airflow. Prune away crossing canes and open the center of
the bush to allow sunlight and airflow. Also, spraying the
foliage with a mixture of 1 T. baking soda per 1 gallon of
water can be effective. See blackspot
for other treatments of powdery mildew.
Propagation:
There are two primary ways to propagate
roses. Asexual reproduction is usually used to produce a duplicate
of the parent plant. Sexual reproduction, i.e. growing roses
from seed, is primarily used to create new varieties of roses.
Common methods of asexual propagation of roses are softwood
rooting, hardwood rooting, and bud grafting. Limited space
permits only a brief description of softwood rooting. Old
Roses, English Roses and Miniatures are generally good candidates
for rooting cuttings because they usually grow vigorously
on their own roots. Modern Roses such as Hybrid Teas and Floribundas
are usually sold budded onto different rootstock. Some Modern
Roses do grow vigorously on their own roots, while others
do not.
Pruning:
There are three main purposes to be
accomplished when pruning roses. Keep the plant healthy. Encourage
the plant to grow in a desired shape. Encourage blooming,
either more blooms or larger blooms. The proper tool for most
pruning is a sharp clean set of bypass pruners. Anvil pruners
should not be used for roses as they crush the stem being
cut. A saw or lopping shears may be used to cut very large
canes (1/2 inch diameter or greater)
All pruning cuts on canes greater than 1/4 inch diameter should
be sealed with nail polish or glue to prevent cane borers
from entering. Proper pruning will help keep a rose bush healthy.
Dead and diseased wood should be removed as soon as possible
to prevent further damage to the bush. The future shape of
the bush can be influenced by the location of each pruning
cut. Opening up the bush to increase air circulation will
help prevent diseases. Since rose bushes like to send out
a strong lateral cane at the node just below a pruning cut,
try to make pruning cuts about 1/4 inch above an "outward"
facing leaf bud. By doing this and removing plant material
from the center of the bush you will create a more open vase-shaped
plant less susceptible to disease. Whenever two canes cross
each other, one can be removed. Roses can be encouraged to
bloom better if thin, weak and non-productive wood is removed
to allow the plant to concentrate its blooming on the larger
healthier canes. Generally with Hybrid Teas any cane thinner
than a pencil should be removed. Plants may be pruned hard
to encourage larger blooms but fewer blooms (commonly done
with Hybrid Teas.) Or the plant may be pruned lightly and
allowed to grow larger and produce more flowers that are smaller
(commonly done with some shrub roses.) Prune first year plants
only lightly to allow them to concentrate on establishing
a strong root system. repeat blooming: (see also once blooming:
) Describes those roses that bloom more than once a year.
This varies from those that only bloom a couple times a year
to those that are in constant bloom. The terms recurrent or
remontant are sometimes used in place of repeat blooming.
Rust:
This fungus is manifest by rust-colored
spots on the underside of leaves and yellow patches on the
upper surface of the leaf.
Shade:
Roses prefer a full day of sun. Give
roses at least 6 hours of direct sun a day. Morning sun is
especially important because it dries the leaves which helps
prevent disease. In general, roses
do poorly in shady conditions. Plants bloom less, are leggy,
and are more likely to get diseases. However, many Hybrid
Musks and some Albas can tolerate partial shade. A few other
varieties including the Floribunda "Gruss An Aachen"
can be planted in partial shade. Other roses that may grow
in partial shade are the Rugosas, Iceberg(FB), Zephirine Drouhin
(Bourbon), Souvenir du Docteur Jamain(HP) and Madame Plantier.
Shrub roses:
The Shrub
roses are the most significant of the modern roses. The "Bush"
roses are divided into Large flowered, Cluster-flowered, and
polyyanthas. Many crosses been made between Larde- and Cluster-
flowered roses, and it has become dificult to discriminate
between them. In the USA, these in-between roses are often
classed as Grandifloras.
Soil:
Roses like rich, well-drained soil.
Raised beds are ideal. Roses prefer a pH of about 6.5 (6.0-6.8),
slightly acid soil. Roses dislike competition for nutrients,
especially roses that repeat bloom. This means that roses
do not like being planted too close to grass and other aggressive
neighbors.
Suckers:
A sucker is a cane that starts from below
the bud union. On grafted roses, suckers should be removed
since they are a different type of rose than the main plant.
With own-root roses, suckers can be kept as they are the same
type as the main plant and add vigor to the plant. sunlight:
Thrips:
Thrips are tiny insects that do cosmetic
damage to roses by ruining the blooms. They may either prevent
blooms from opening, or if the blooms do partially open they
will have brown or black spots. Thrips prefer light-colored
flowers. Thrips can be controlled by spraying the buds and
blooms with Orthene.
Virus:
There are several types of virus that
affect roses, but the most common is the mosaic virus. It
causes interesting yellow patterns to form on some of the
otherwise healthy green leaves of the plant, hence the name
mosaic. Plants with virus will usually live, but they will
be less vigorous than non-virused plants. Mosaic can not be
transmitted from one plant to another by pruning. It can be
transmitted by grafting a healthy rose onto a virused rootstock,
or less likely, by grafting a virused rose onto a healthy
rootstock.
Watering:
Roses appreciate lots of water. Water
generously, at least 1 inch/week, preferably 2 inches/week
during growing season. Water every 4-7 days during the summer
when needed. Each bush needs about 4-5 gallons/week during
the hot summer. Roses get all their food either through their
leaves (foliar feeding) or through their roots. The only medium
for transporting food is water. Infrequent deep watering is
preferred to frequent light watering to help promote a deep
root system. Deep root systems help the rose to survive both
droughts, and winter freezes. Frequent, light watering causes
roots to form very near the soil surface, making the plant
more susceptible to summer 'baking' and winter freezes. Try
to avoid getting the leaves wet (which promotes disease) when
watering late in the day. However, on hot days wetting the
foliage can reduce transpiration and relieves heat stress.
Winter protection:
Local advice
is preferred for this question, but here are some general
guidelines for winter care of rose bushes for those living
in colder climates. The major dangers to the plant in winter
are the drying of the wind, the effect of alternate thawing
and freezing cycles on the plant when winter temperatures
fluctuate, the inability of the plant to take in water if
the soil is frozen, and damage from the cold itself to the
canes and bud union.
If you live in an area with harsh winters,
plant cold-hardy roses. Your choices are more restricted that
way, but you will save yourself a lot of work and heartbreak.
Many once blooming old roses are very cold-hardy; of the repeat
bloomers, rugosas are rock-hardy, and many Austins and other
shrub roses will do okay. Many yellow and lavender roses are
especially tender. Unfortunately cold-hardiness is not an
exact science; conditions such as wind affect roses severely
in cold weather (by drying them out), and so zone ratings
are only a first approximation.
When in doubt, plant own-root roses.
If they die back to the ground in a particularly severe winter,
they will grow back from the roots fairly quickly. This advice
is not applicable to once-bloomers, because these usually
flower only on the last year's canes. Own-root Old Roses and
English roses are available. Hybrid Teas are almost always
sold as grafted plants, and it is difficult to find own-root
plants. In the fall, reduce the amount of Nitrogen fertilizer
used. This, combined with lower temperatures, will slow the
production of new tender growth, and will allow the existing
growth to harden off. Stop deadheading about September 1 for
zones 4 and 5. This will allow the plant to form hips. The
formation of hips encourages the plant to slow down growth,
slow blooming, and harden the canes, all preparing the plant
for dormancy.
Understanding rose dormancy will help
to determine the proper time to prune during the period from
late Fall to early Spring. During dormancy, the sap has left
the canes and they are simply empty tubes of cellulose. Pruning
too early (before the sap runs back) cuts some of the nutrients
out, so you must be sure the plant is dormant before fall
(winter) pruning. Winter die-back generally occurs from the
end of the branches (canes). Pruning removes the available
length that can die back before reaching the ground. Also,
pruning a semi-dormant plant stimulates growth and sap flow
in the pruned region. For a plant going dormant, this is bad
because it inhibits dormancy.
For a plant waking up (springtime) it's
good because it stimulates growth. Ideally pruning should
occur before sap is fully flowing. To prevent disease/fungus
from overwintering, clean the rose bed by removing leaves
and other debris. Spray the bush with dormant oil to kill
bacteria on the bush and on the ground. Protect the crown
of the rose. This is critical since the crown is where you
want the new canes to come from.
There are several methods of protection
to choose from. Cover the bed at least a foot deep with tree
leaves. Do not use rose leaves as they may harbor disease.
Oak leaves are best as they seem to drain better. Cover the
bed with straw. Use rose cones. Make a mound with soil or
mulch to cover the crown. Wrap the whole plant in burlap if
necessary, in addition to one of above methods of protecting
the crown. Timing is important. Covering the rose too early
is unwise as it may prevent the rose from hardening properly
and will slow the onset of dormancy. Covering the rose too
late may risk damage from the cold. Climbers or long canes
may benefit from being tied to avoid thrashing from the wind.
Canes may be protected from drying winter winds by wrapping
them in burlap with a layer of straw for insulation. In severe
climates long canes may need to be tied and buried. Keep the
soil well-drained, especially as the spring rains come.
