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Roses in Mississippi

History of Roses

The rose is probably the most popular of all garden flowers. Roses grow in every part of the United States and are dominant in many landscape designs.

The popularity of roses is not new. The most important reasons for their continuing popularity are their fragrance and their wide range of striking colors, visible in gardens from early spring until late fall.

Rose fossil evidence dates back 35 million years. Six centuries before Christ, a poetess, Sappho, glorified the rose as "Queen of Flowers," a title that remains undisputed. The luxury-loving Nero was said to be fond of staging rose feasts. It is reported that at times he spent the equivalent of $150,000 to provide roses for a single banquet!

In other historical periods, the rose was so rare and scarce that even royalty considered a small bottle of rose water a precious gift.

Roses were in such demand in the 17th century that they were used to settle debts. In the early part of the 19th century, Empress Josephine, being fond of roses, requested that a plant of every specimen in Europe be represented in her garden. As a result, French rose growers were greatly inspired and soon began introducing new varieties. Today there are more than 6,500 varieties of roses. New varieties developed by plant breeders are introduced each year. With proper variety selection and subsequent care, it is easy to grow beautiful roses in Mississippi.

For best success in growing roses, the home gardener must assume a few important commitments and responsibilities:

  1. Buy vigorous, healthy plants from a reputable garden center or mail-order nursery.
  2. Select a plant site that receives a minimum of 6 hours direct sunlight daily and has soil that is fertile and well-drained.
  3. Be persistent with a regular spray program to prevent insect and disease damage.
  4. Protect plants from winter injury by proper mulching, watering, and fertilization schedules to allow the plants to acclimate.

 

Know Your Roses

Bush Roses

Hybrid teas are a popular form of bush rose often used for cut flowers -- usually single bloom on a long stem.

Floribundas bear flowers in clusters. Individual blooms of many varieties resemble hybrid teas. Floribundas tolerate neglect better than any other type of rose except shrub roses. Good for mass color in beds.

Grandifloras resemble hybrid teas in type of bloom and in hardiness although flowers are somewhat smaller. Grandifloras bloom more abundantly than hybrid teas.

Polyanthas bear flowers smaller than grandifloras and in large clusters. They are excellent for mass planting or for borders with perennials and are of easier culture than hybrid teas.

Hybrid perpetuals are the "June roses" of grandmother's garden. They produce large flowers, usually lacking the refinement of hybrid teas. Before development of modern hybrid teas, hybrid perpetuals were popular. They usually develop large, vigorous bushes if given good cultural care and pruning. They are hardy and withstand low winter temperatures without protection.

Shrub roses include a miscellaneous group of wild species, hybrids, English shrubs, and varieties. These may be small or large with upright, spreading, or bushy growth useful in general landscape schemes. Flowers may be small or large, showy, and have light to intense fragrance. Some bloom once a year, and others have repetitive bloom cycles. Many bear attractive fruit (hips) in the fall.

Tree or Standard Roses

These rose plants are distinctive because of plant form rather than flower type. Bush-type roses are grafted on upright trunks. Many popular bush rose varieties are available as tree roses. They are often used in formal plantings, as accent plants, and as urn or tub specimens.

Miniature Roses

Plants and flowers are very small. For most varieties, maximum height is 12 inches. They are used mostly for rock gardens, edging beds and borders, and pot plants. Miniatures have become very popular since 1970. Many new varieties are available.

Climbing Roses

All varieties produce long canes and require some support to hold plants up off the ground. Climbing roses are used on banks to aid in holding soil, and they are often trained on trellises or fences. Climbers are hardy plants and are becoming more popular with development of finer varieties. Climbers, like bush roses, are grouped into several types, with much overlapping among types. Most rose nurseries list rambler, large-flower climber, everblooming hybrid teas, climbing polyanthas, climbing floribundas, and trailing roses.

Ramblers are very hardy and rapid growing, sometimes developing canes as long as 20 feet in a season. Flowers are small, less than 2 inches across, and are borne in dense clusters. Plants flower once in a season, on year-old wood. Foliage is glossy, but many varieties are susceptible to mildew. They are being replaced by other climbing types that bear larger flowers during long growing season and are less subject to mildew.

Large-flowered climbers are slow-growing in comparison to ramblers, are often trained on posts or some other type of support, and may require heavy annual pruning. They are adapted to small gardens for use on fence, wall, or small trellis. When well-grown, flowers are large and useful for cutting. Many varieties do not bloom as freely when canes are trained vertically as when trained horizontally.

Everblooming climbers usually bear an abundance of flowers in early summer. After this period of heavy bloom, plants produce a few scattered flowers until fall. Then, if growing conditions are favorable, plants may bloom heavily again. Plant breeders are rapidly improving this type rose. Some everblooming climbers bloom as continuously as hybrid teas and are more winter hardy.

Climbing hybrid teas are seedlings and chance sports of bush varieties. When a bush hybrid tea produces a cane that has the climbing character, the new type is usually given the same name as the bush variety from which it originated. Climbing forms, in general, do not bloom continuously as do their bush parents, but flowers and foliage usually are identical.

Climbing polyanthas and floribundas are sports and seedlings of polyanthas and floribundas. Flowers generally are identical with their original bush forms. They are fairly continuous in blooming and hardier than climbing hybrid teas.

Trailing roses are climbers adapted to use on slopes, banks, and walls. They produce large canes that creep along the ground, making a pleasing ground cover. Flowers are not as attractive as other types, but plants are hardy.


Rose Varieties That Perform Well in Mississippi Gardens

@ Designates All-America Rose Selection Award Winners as judged by The American Rose Society.

Hybrid Teas

Red/Orange

Alec's Red -- medium red
@ Chrysler Imperial -- dark red
Crimson Glory -- dark red
@ Double Delight -- red blend
Folklore -- orange/orange blend
@ Granada -- red blend
Las Vegas -- orange/orange blend
Lover's Meeting -- orange blend
@ Mister Lincoln -- dark red
Oklahoma -- dark red
@ Olympiad -- medium red
Proud Land -- dark red
@ Seashell -- apricot blend
@ Tropicana -- orange red

Mauve

Kolner Karneval
Lady X
@ Paradise -- mauve blend
Steven's Big Purple

Pink

Alabama -- pink blend
Captain Harry Stebbins -- deep pink
Century Two -- medium pink
@ Charlotte Armstrong -- deep pink
Chicago Peace -- pink blend
@ Color Magic -- pink blend
Confidence -- pink blend
Cynthia -- deep pink
Dainty Bess -- light pink
@ Duet -- medium pink
@ Electron -- deep pink
@ First Prize -- pink blend
Keepsake -- medium pink
Marijke Koopman -- medium pink
@ Miss All-American Beauty -- medium pink
@ Perfume Delight -- medium pink
@ Royal Highness -- light pink
Swarthmore -- pink blend
@ Tiffany -- pink blend

Yellow

@ King's Ransom -- deep yellow
Lemon Sherbet -- light yellow
@ Oregold -- deep yellow
@ Peace -- yellow blend
Sunbright -- medium yellow

White

@ Garden Party
@ Honor
Ivory Tower
@ Pascali
Pristine

Apricot

Brandy -- apricot blend
Just Joey -- apricot blend
Medallion -- apricot blend

Miniatures

Red/Orange

Acey Deucy -- medium red
B.C. -- dark red
Beauty Secret -- medium red
Chattem Centennial -- orange red
Dreamglo -- red blend
Magic Carousel -- red blend
Mary Marshall -- orange blend
My Valentine -- dark red
Orange Honey -- orange/orange blend
Over the Rainbow -- red blend
Starina -- orange red
Toy Clown -- red blend

Mauve

Lavender Jade -- mauve blend
Lavender Jewel -- mauve
Winsome -- mauve blend

Pink

Baby Betsy McCall -- light pink
Choo Choo Centennial -- light pink
Cupcake -- medium pink
Jennifer -- pink blend
Judy Fischer -- medium pink
Kathy Robinson -- pink blend
Kingig -- medium pink
Peaches and Cream -- pink blend

Yellow

Dreamboat -- medium yellow
Genevieve -- yellow blend
Party Girl -- yellow blend
Rise 'N Shine -- medium yellow
Sequoia Gold -- medium yellow
Swinger -- medium yellow

White

Green Ice
Little Eskimo
Snow Bride
Starglo

Apricot

Buffy -- apricot blend
Jean Kenneally -- apricot blend
Loving Touch -- apricot blend
Free Spirit -- apricot blend

Polyanthas

Red/Orange

Margo Koster -- orange/orange blend

Pink

China Doll -- medium pink
Cecile Brunner -- light pink
Lady Ann Kidwell -- deep pink
The Fairy -- light pink

Floribundas

Orange/Red

Amber Queen -- apricot blend
@ Apricot Nectar -- apricot blend
@ Europeana -- dark red
@ Impatient -- orange red
@ Marina -- orange/orange blend
@ Showbiz -- medium red

Mauve

@ Angel Face

Pink

Betty Prior -- medium pink
@ Cherish -- medium pink
@ Fashion -- pink blend
@ First Edition -- orange pink
@ Gene Boerner -- medium pink

Yellow

@ Sun Flare -- medium yellow
@ Sunsprite -- deep yellow

White

Evening Star
@ French Lace
Iceberg

Grandifloras

Orange/Red

@ Love -- red blend
Montezuma -- orange red
@ Shreveport -- orange/orange blend

Pink

@ Camelot -- medium pink
@ Queen Elizabeth -- medium pink
Sonia -- pink blend

White

@ White Lightin'

Yellow

Gold Medal -- medium yellow

Shrubs

Orange/Red

Dortmund -- medium red
Hansa -- medium red
Prospero -- dark red
Ruskin -- dark red

Pink

Carefree Beauty -- medium pink
Flamingo -- deep pink
Frau Dagmar Hartopp -- medium pink
Heritage -- light pink
Mary Rose -- medium pink
Pink Grootendorst -- medium pink
Wanderin' Wind -- light pink

Yellow

Golden Wings -- medium yellow
Graham Thomas -- dark yellow

White

Blanc Double de Coubert
Fair Bianca
Nevada
Prairie Star

Apricot

Charles Austin -- apricot blend
Bredon -- apricot blend
Leander -- apricot blend

Climbers

Orange/Red

Altissimo -- medium red
Blaze -- medium red
Chrysler Imperial -- dark red
Don Juan -- dark red
Double Delight -- red blend
Dublin Bay -- medium red
Floradora -- orange red
Paul's Scarlet -- medium red

Pink

Blossomtime -- medium pink
Dainty Bess -- light pink
Dr. W. Van Fleet -- light pink
Galway Bay -- medium pink
New Dawn -- light pink
Tiffany -- pink blend

Yellow

@ Golden Showers -- medium yellow
Lawrence Johnston -- medium yellow

White

Sombreuil
White Dawn

Landscape Uses

Floribundas, grandifloras, polyanthas, and hybrids are some of the best flowers for color accents in the landscape. They are excellent to use in mass plantings, such as at the base of hedges and shrubbery borders. In the past, hybrid teas were more widely grown than all other types of roses. When the word "rose" was used, it generally suggested a hybrid tea variety.

In recent years the popularity of the floribunda, grandiflora, and shrub roses has increased because of the improved varieties, mass display of flowers, and general renewed appreciation of old rose types. Roses are seldom acceptable as foundation plants since their true beauty lies in the flowers rather than the plants, which are bare during the winter.

Climbing roses and ramblers need support such as a post, trellis, or wall. In some few cases, with houses of informal design, they are appropriate to be trained as "vines" on fences and walls. Roses require at least 6 hours of sun daily but prefer 8 to 10 hours. Morning sun is preferred to afternoon sun. They should be located away from trees and landscape shrubs. A rose-cutting bed, the ever-popular collection of tea roses, should be placed in the open where there is no competition from roots of other plants.

Buying and Handling Plants

Get your rose plants from reputable dealers. Local nurseries and garden centers are good sources. In addition, mail-order companies will send you colorful catalogs listing the plants they sell. It is advisable to place orders early to get the best plants. The varieties listed in these catalogs also include some favorites with rose growers. Recommended varieties are listed above.

Container-grown roses may be planted at any time of the year, with excellent possibilities for successful growth. There is much discussion among rose growers as to when to set bare-root plants in Mississippi, fall or spring. Good results have been gained by planting in both seasons if plots are properly cultivated, but early spring planting is preferred.

Commercial growers may be located in areas where plants do not become dormant until late winter, and they will not dig and ship these plants until late winter or early spring. Usually, Mississippi soils are not truly cold enough to set dormant plants until late winter or early spring. The ideal time is when the plants are still dormant. Plants grown in containers may be planted at any time.

Preparing Soil, Planting, and Fertilizing

First Things First

Not all rose plantings are successful because there is more to planting roses than digging a hole, spreading out the roots, and replacing the soil. Before you remove any soil, consider several things:

  1. Has the soil already grown roses for many years?
  2. Does the soil need improving?
  3. Is the site suitable for roses?

The first step is to pick the right spot. Plenty of sun is required to produce top quality roses, but light shade during early afternoon is beneficial. Roses cannot stand deep and continuous shade. Shelter from cold wind is helpful. A nearby hedge or fence is useful, but it should not be close enough to shade the bushes. Avoid planting in the lowest part of the garden if it is a "frost pocket." Roses do not thrive in exposed, low-lying sites. Plenty of air is required to produce healthy plants.

Bush and standard roses do not like being shut in by walls and overhanging plants. Roses cannot tolerate being planted under trees.

Suitable soil is necessary, and fortunately this can be achieved in nearly all gardens. Ideally, it should be a medium loam, with free internal drainage, slightly acid, and rich in organic matter and fertilizer nutrients. A high clay content is not necessary and can be harmful if poor drainage occurs. A high lime content is almost impossible to overcome. Free drainage is necessary. Roses cannot withstand being waterlogged.

Instructions for preparing a raised rose planter bed are shown later in this publication. Most all plantings would benefit from the raised-bed concept. Prepare the soil in the fall, whether for fall or spring planting. This will allow time for "settling." The medium within the planter should be a 1-1-1 mixture of topsoil, builders sand, and organic matter. The organic matter could be decayed sawdust, peat moss, or pine bark fines. Soil test to determine the proper amount of lime and fertilizer to add to the bed. Lime and phosphorus can be added in the fall, while other elements should be added at the time of planting or when growth begins in the spring.

Spacing. Space hybrid teas, grandifloras, and polyanthas 3 feet X 3 feet in the bed. Space floribundas 4 feet X 4 feet. Space miniature roses 1 foot apart. Plant hybrid perpetuals 5 feet apart, and climbers at least 10 feet apart.

Plant Roses Carefully. If you're planting a few roses, dig individual planting holes. Make holes at least twice the size of the root mass and 12 inches deep. For a large number of roses in a continuous bed, prepare bed by spading soil to a depth of about 12 inches. Dig planting holes in the prepared bed.

Make a small mound of prepared soil in the planting hole. Spread the roots over the mound and set plant to proper depth. Backfill the planting hole with prepared soil, and firm with hands. Water the soil thoroughly immediately after planting. Avoid planting too high or too deep.

Examine the canes carefully for proper pruning before planting. Canes should be cut at an angle approximately one-fourth inch above a node. To prevent a delay in flowering, do not cut canes shorter than 10 inches.

To help conserve soil moisture and aid in successful reestablishment, mulch newly planted roses with a 4- to 6-inch layer of pine straw or pine bark. During dry periods, water thoroughly every 8 to 12 days.

Fertilizing. Soil tests should be made before fertilizing plants. Fertilize after plants initiate growth. Depending on the type of fertilizer being used, applications may be required every 4 to 6 weeks during the growing season to sustain good growth. Do not fertilize plants after August. The fertilizer should be watered into the soil immediately after application. Follow the soil test recommendations.

Pruning

Prune roses each year between February 20 and March 15. Pruning roses isn't difficult, but it does require sharp tools. The hybrid teas, grandifloras, and floribundas are all pruned in a similar manner.

First, remove all dead or diseased-looking wood. Then cut out all the weak canes or any branches that are growing inward toward the center of the bush.

For the hybrid teas and grandifloras, select 3 to 6 strong canes and cut them back to a height of 12 to 18 inches. With floribundas, it is often desirable to leave more canes of a greater height (24 to 30 inches), depending on their location in the landscape.

You will prune climbers less severely and at a different time from bush roses since they produce their flowers on wood of last season's growth. They should be pruned following bloom. In general, pruning climbing roses usually involves shaping the plants to a desired growth pattern or the complete removal of one or two of the oldest canes.

Cutting Blooms

When cutting a rose from the plant, make the cut at a 5-leaflet leaf. Such a cut will ensure strong vegetative breaks and will make for more vigorous plants.

For Large, Single Flowers. When you want large, single, decorative-type flowers, you will want to disbud the plants when the buds are small. Remove all buds from the stem except the terminal one (tip bud).

Propagation

Even though you can "root" some rose varieties, it is usually advisable to buy vigorous 2-year-old plants from a reliable nursery. Most of the newer varieties are difficult to propagate. Many of them are patented, and their propagation is not legal unless permission is obtained from the breeder.

Sprays for Insects and Diseases

Pesticide applications are usually needed throughout the year to protect roses from diseases, insects, or mites. For convenience, it is often practical to combine recommended insecticides and fungicides into one spray unless label directions specifically prohibit this practice. Commercial mixtures of these materials are available for use as sprays or dusts. Caution: Do not store pesticides after they are mixed with water. Mix only the amount you will need for one application. Be sure to follow label directions for safe and efficient use of any pesticide.

Insects

Thrips

Thrips feed on tender growth within flower buds, causing discolored and deformed flowers. White varieties seem particularly susceptible to attack by this pest. The adults are tiny, slender, brownish-yellow insects with feather-like wings. They move very quickly when disturbed.

Thrip populations breed and reproduce in early season on various weeds, clovers, and grasses. Roses become infested with thrips when they migrate from these wild host plants. Peak migration may occur in Mississippi from late April through mid-June. Inspect plants on a regular basis during this period.

Aphids

Aphids are small soft-bodied insects that appear on new stems and buds in early spring. They damage the plant by withdrawing plant juices from new growth, resulting in reduced flower quality. The aphids commonly found on roses are green, although some have a pink coloration. These insects secrete a material (honeydew) that gives the leaves a shiny appearance. Honeydew is high in sugar content and causes the leaves to be sticky. Aphid populations are highest during the spring and fall.

Rose Scale

Rose stems or branches sometimes become covered with white insects known as rose scale. They do not resemble insects but can cause a lot of damage by sucking the sap from the plants.

Cygon, when applied thoroughly to all areas of the plant, is effective. Make several applications at weekly intervals in the spring. Other applications of insecticides later in the season for thrips or other insects will help keep rose scale under control.

When pruning the plants during the dormant season, remove the most severely damaged stems. Oil emulsion applied at this time will control rose scale. The frequent pruning of roses keeps populations of this pest at a very low level.

Spider Mites

Spider mites remove plant sap through small, needle-like mouthparts. During the feeding process, they destroy the chlorophyll or green-colored material around the feeding puncture. Light infestations will cause a stippled pattern on the leaf. Later, however, the individual spots run together, the leaf becomes bronze, then yellowish, and finally it turns brown and prematurely drops from the plant. Many of the spider mites produce a mat of fine webbing over the leaves, adding an unsightly appearance to the plant.

Serious infestations of this pest develop rapidly due to its very short life cycle. Early detection is one of the keys to good control. Look for spider mites during periods of hot, dry weather.

Leaf-Cutter Bees

Leaf-cutter bees cut small circular pieces from rose leaves as food for their young. They store the food in burrows they have dug in the pith of rose stems and broken branches. This tunneling usually causes the stem to die. Sevin appears to be fairly effective in controlling leaf-cutter bees.

Beetles

A number of hard-backed beetles attack roses. They usually feed on the young buds of roses and open flowers, riddling them with holes. Usually, you see only the damage since the beetles feed mostly at night.

Other Insects

These insects occur rarely in Mississippi and are described for informational purposes only.

Rose stem borers attack the stems of roses, causing them to die back. Rose galls are caused by wasp-like insects laying their eggs in the stems of roses. When the eggs hatch, the larvae cause large swellings or galls to form on the stems. Prune stems attacked by rose stem borers or gall insects.

The rose midge is sometimes a pest of roses. This tiny yellowish fly lays its eggs in the growing tips of the rose stems. Its larvae or maggots attack the stem tissue, causing deformed buds. To control, prune infested tips, and spray with one of the materials from the insecticide chart.

Prepare your spray properly.

Table 1. Insecticides to control insects and spider mites.

Insect Material * Amount to mix per gallon of water
Thrips Cygon 23.4 % E.C.
or Orthene 9.4 E.C.
2 tsp
3 tbsp
Aphids Orthene 9.4 E.C.
or Malathion 57 E.C.
or Diazinon 25 E.C.
2 tbsp
1 tbsp
2 tsp
Spider Mites Cygon 23.4 E.C. 2 tsp
E.C. = emulsifiable concentrate; tsp = teaspoon; tbsp = tablespoon
* The insecticides listed on the chart will help control other pests that may occur on roses. Remember, early pest detection and good spray coverage are keys to good control.

 

Diseases

Many diseases affect roses. Some are caused by fungi, others by bacteria or viruses. Black spot, powdery mildew, and stem canker, the three most prevalent and most costly diseases of roses in Mississippi, are caused by fungi. Although varieties may differ in their susceptibility to these diseases, you cannot grow roses successfully without control of these three diseases.

A preventive disease control program is essential if you are to be successful in growing roses. Unless otherwise stated, the fungicides listed in Table 2 can be mixed with the most commonly used insecticides. In general, a good preventive disease control program calls for weekly sprays during the spring and early summer and every 2 to 3 weeks during the dry part of the growing season. Be sure to read label directions carefully.

Black Spot
Diplocarpon rosae

As the name black spot implies, the most prominent symptom of this disease is black spots on either side of the leaves. A number of other diseases cause dark spots in the leaves, but you can distinguish black spot by the darker color and the uneven border of the spots.

Generally along with black spots you will see chlorosis or yellowing of the green part of the leaf.

Premature defoliation is also a sign of the disease. Sometimes the plant will hold its leaves until the black spot grows to the size of a dime. In other instances, the leaves may fall soon after infection before you notice the black spots.

Although rose varieties may vary in their susceptibility to the fungus, no variety is completely immune; however, a few varieties do show high resistance. Hybrid teas generally are more susceptible than are other varieties.

Control. The first step toward controlling black spot is sanitation. If only a few leaves show symptoms of black spot on a plant, remove and burn them. Remove all diseased leaves from around the plants, particularly at the end of the growing season. The fungus overwinters in part in diseased leaves and also in the canes. It is sometimes wise to prune canes drastically, without cutting too close to the graft, before new growth begins in the spring. Before new foliage occurs, remove and burn all old mulch. Replace with new mulch.

In addition to sanitation practices, use a dormant spray of liquid lime-sulphur, 1:15, just before the time the leaves begin to emerge. While the value of this practice is doubtful in controlling black spot, it does help control a number of other overwintering pests, including powdery mildew.

A regular spray program throughout the growing season is necessary to control black spot. You may use any one of several fungicides, including Maneb (Manzate), Daconil 2787, or Funginex. All give good control of black spot if applied at weekly intervals during the spring and at two-week intervals during the summer. These are usually combined with an insecticide or miticide and a spreader sticker.

Outstanding results have been obtained with these fungicides with thorough coverage. If you follow the suggested spray schedule and use good sanitation practices, you should prevent black spot. Be sure to follow label directions closely. A fungicide application program should be used in conjunction with good sanitation.

Regular spraying and thorough coverage are important for control. These fungicides protect the plant from infection. Once plants are infected, the fungicides are of little value. For this reason, keep your plants covered with a protective fungicide at all times during the growing period. For more information concerning black spot, ask your county Extension agent for Plant Disease Dispatch Ornamentals M-317.

Powdery Mildew
Sphaerotheca pannosa

A white, powdery fungus growth on the surface of leaves, buds, or stems of roses usually indicates powdery mildew. Infection on young leaves may cause curling and sometimes a purplish coloration. Young canes may be infected a foot or more from the tip and can be killed. Badly infected flower buds do not open.

Control. Most of the sanitation procedures for black spot are also valuable in controlling powdery mildew. Where this disease is a problem, spray dormant plants with commercial lime-sulphur 1:15.

During the growing season, you can hold mildew in check by spraying with Bayleton or wettable sulphur at 8 tablespoons to a gallon of water. A spreader sticker should be added to the spray. Chemicals for powdery mildew control, particularly sulphur, may burn the foliage if applied when the temperature is 90 °F or above. Apply the fungicide when you first note infection and then every 7 to 10 days as needed. For more information concerning powdery mildew, ask your county Extension agent for Plant Disease Dispatch Ornamentals M-314.

Stem-Cankers and Die-Back
(Several Fungi)

This is one of the most serious diseases of roses in the South. A large number of fungi can cause diseases on the canes. Identifying these stem-canker diseases is not of great importance since the control is much the same for all. This disease generally is more prevalent on plants that have been severely defoliated by black spot. Stem-canker also may cause a die-back of the cane. Careful selection of disease-free plants is the first step to control.

Cutting and burning cankered canes as soon as detected is the principal control. Remove the diseased canes at least 5 inches below the last sign of injury. Protect all cut areas with a wound dressing. General sanitation practices each dormant season are always helpful.

Gray Mold
Botrytis cinerea

Terminals of canes infected with gray mold droop and fall over. A grayish-black lesion on the infected terminal usually extends down the stem of the infected cane. Infected buds may appear blasted and will loop over at or near the lesion. When you examine the exterior of such buds, you may find a cob-webby mold. During warm, humid weather, a gray fungus may cover the infected parts.

Control. Cut and burn all infected parts as soon as they appear. Prune the infected parts at least 2 inches below the last sign of infection. Spray with Daconil 2787 as you would for control of black spot.

Crown Gall
Agrobacterium tumefaciens

Gall-like growths occur at or near the soil line but also may be found on the upper stems or on the roots. Infected plants become stunted, and the blossoms and foliage are not of good quality.

Remove and burn all infected plants. Do not replant in infested soil. Move new plantings to a new location in the landscape. The disease is easily spread by pruning shears and other equipment used around infected plants.

Viruses
(Several)

A number of virus diseases attack roses, resulting in a multitude of symptoms such as yellowing, streaking ring spots, and puckering and curling of the new leaves. The plants may be stunted with imperfect buds. The viruses can be transmitted by insects, grafting, or on pruning equipment.

Control. The best method of control is to buy virus-free plants from a reputable dealer. When you notice infected plants, remove and destroy them. Also, good insect control helps keep the problem from spreading.

If you encounter other diseases, consult your county Extension agent, home economist, or Extension plant pathologist.

Table 2. Fungicides that control diseases on roses.

Common Name Trade Name (percent a.i.) Diseases Controlled
Chlorothalonil Daconil 2787 (40.4%)

Daconil 2787 (75%)
Daconil 2787 WDG (90%)
Multi-purpose Fungicide Daconil 2787 (29.6%)

Black spot, Botrytis gray mold
Fenarimol Rubigan A.S. (11.6%) Black Spot
Mancozeb Dithane DF (75%)

Dithane F-45 (37%)
Dithane M-45 (80%)
Fore (80%)
Manzate 200 DF (75%)
Penncozeb Turf & Ornamental Fungicide (80%)

Black spot, Cercospora leafspot, and Rust
Maneb Maneb 80 (80%)
Maneb plus Zinc F4 (37%)
Maneb Liquid Fungicide (21.2%) Maneb Spray (80%)
Black spot, Cercospora leafspot, and Rust
Propiconazole Banner (14.3%)
Systemic Fungicide for Turf & Ornamentals (0.88%)
Black spot, Powdery mildew, and Rust
Thiophanate-methyl Cleary's 3336-F (46.2%)

Cleary's 3336-WP (50%)
Fungo FLO (46.2%)
Topsin M Turf & Ornamentals Fungicide (70%) Topsin M 4.5F Turf & Ornamentals Fungicide (46.2%)

Black spot, Powdery mildew, and Botrytis gray mold
Thiophanate-methyl plus Mancozeb Zyban (15% plus 60%) Black spot, Botrytis gray mold, and Powdery mildew
Triforine Triforine EC (18.2%)
Funginex Rose Disease Control (6.5%)
Black spot, Powdery mildew, and Rust
Vinclozolin Ornalin WP (50%)
Ornalin FL (41.3%)
Botrytis gray mold
Ziram Ziram F-4 (39.2%)
Ziram 76 (76.0%)
Black spot and Powdery mildew

It is best to alternate a systemic fungicide with one of the protectant fungicides to prevent the build-up of resistant strains of the fungus. Propiconazole, thiophanate-methyl, and triforine fungicides are systemic. This means that the fungicide is translocated to other parts of the plant that originally hit.

Reference to commercial products or trade names is made with the understanding that no discrimination is intended of other products that also may be suitable and have label clearances.

 

How To Plan a Rose Planter

Materials Needed

  • 8 old crossties 6 in X 7 in X 8 ft long
  • 1 cubic yard of sand
  • 1 cubic yard of organic matter (rotted manure, fine pine bark, or compost)
  • 1 cubic yard of loam topsoil

Procedure

  1. Locate area that receives minimum of 6 hours full sun.
  2. Avoid low, wet soils.
  3. Mark measurements for bed size.
  4. Spade soil with shovel, then till well, removing grass and weeds.
  5. Set crossties firmly according to plan.
  6. Add half of the organic matter; spread in even layer.
  7. Add sand in even layer.
  8. Add remaining organic matter in even layer.
  9. Add loam soil.
  10. Till thoroughly.
  11. Plant roses as described above.

Reference to commercial products or trade names is made with the understanding that no discrimination is intended of other products that also may be suitable and have label clearances.

Revised by David Tatum, Extension Nursery Specialist; J. A. Spencer, Professor of Plant Pathology; Mukund V. Patel, Extension Plant Pathologist; and James Jarratt, Extension Entomologist.

Mississippi State University does not discriminate on the basis of race, color, religion, national origin, sex, age, disability, or veteran status.

Publication 529
Extension Service of Mississippi State University, cooperating with U.S. Department of Agriculture. Published in furtherance of Acts of Congress, May 8 and June 30, 1914. Ronald A. Brown, Director

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