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Introduction
- Bette Midler sang about it. William Shakespeare, Gertrude Stein and Robert Burns wrote about it. It is the national flower of both the United States and Great Britain. It is the rose, and it is a favorite of many gardeners around the world. If you want it to become a part of your garden, then here is a basic guide on how to plant and grow roses.
Step 1: Understanding the Different Types of Roses
- Roses can be classified in a variety of ways including by growth habit, lineage and flowering characteristics. Rather than go into the thousands of different types of roses, a general overview of the different classifications is given.
- Bush roses: Self-supporting and grow upright. They can range from 6 inches to 6 feet in height.
- Climbing roses: Produce long, vigorous canes that need support and may grow over 20 feet in length.
- Ground covers: Low growing varieties that can reach 2 1/2 feet in height.UC IPM Online: Roses: Cultural Practices and Weed Control Management Guidelines
- Modern roses: One of the three main groupings of roses.American Rose Society: Classification of Roses It includes all classes of roses that were in existence after 1867 including all miniature, hybrid tea, shrub, floribunda, grandiflora as well as all climbing varieties of these types.
- Mounding shrub: Roses that are more rambling than upright varieties.UC IPM Online: Roses: Cultural Practices and Weed Control Management Guidelines
- Old garden roses: One of the three main groupings of roses.American Rose Society: Classification of Roses It includes all classes of roses that were in existence before 1867 including all tea and climbing tea varieties.
- Species roses: One of the three main groupings of roses.American Rose Society: Classification of Roses These are from the genus Rosa and are found growing naturally throughout the Northern Hemisphere.University of Illinois Extension: Species Roses Species roses often have single blossoms that bloom once a year, are very hardy and disease resistant.
- Upright plants: Medium to large shrub roses with uniform foliage and bloom.UC IPM Online: Roses: Cultural Practices and Weed Control Management Guidelines
- For more information about the different varieties of roses, check out any of the following links:
- All-America Rose Selections: Types of Roses
- Clemson Extension: Growing Roses
- University of Illinois Extension: Different Kinds of Roses
- American Rose Society: English and Other Shrub Roses | Old Garden Roses and Older Roses | About Miniature and Mini-flora Roses
Step 2: Planting Roses
- Roses should be planted in the fall or early spring while they are still dormant.Rose Magazine: Rose Growing the Easy Way
- Choose a location that receives at least 6 hours of direct sunlight every day.Kansas State University: Growing Roses
- Spots that receive morning sunlight are preferable to sites that receive afternoon sunshine.Rose Magazine: Rose Growing the Easy Way
- Make sure the site allows for good air circulation.University of Rhode Island Landscape Horticulture Program: Planting Roses
- Soil should be well draining.University of Rhode Island Landscape Horticulture Program: Planting Roses
- Roses prefer a soil with a pH level between 5.5 and 7.0.University of Rhode Island Landscape Horticulture Program: Planting Roses
- Plant spacing varies according to the variety. Here is a basic guideline of how roses should be spaced:
- Hybrid teas, floribundas & grandifloras: 18 to 30 inches
- Shrub Roses: their mature height
- Climbers (on fences): 8 to 12 feet
- Climbers (on walls): 3 feet
- Miniatures: 12 to 15 inchesUniversity of Rhode Island Landscape Horticulture Program: Planting Roses
Step 3: Fertilizing Roses
- Fertilizing should be done on a regular basis. How much and how often will depend on various factors. Some will recommend fertilizing once a month, others only three times a year.Spring Valley Roses: How to Grow Roses University of Illinois Extension: Watering, Mulching and Fertilizing Roses Therefore, you should test your soil before applying any fertilizer.Alabama Cooperative Extension System: Growing Roses
- Soils around existing rose bushes usually lack nitrogen and potassium.Alabama Cooperative Extension System: Growing Roses
- Using a higher nitrogen fertilizer at the beginning of the season will promote leaves and roots to grow.The Gardener's Network: Rose Care and Feeding
- Phosphorus helps promote flowers to bloom.The Gardener's Network: Rose Care and Feeding Use a fertilizer that is higher in phosphorus once buds begin to appear.The Gardener's Network: Rose Care and Feeding
- Roses are susceptible to iron chlorosis. This will cause leaves to turn a light-yellow color while the stems remain a dark green. It can be treated by spraying iron chelate onto the leaves.Kansas State University: Growing Roses
- Various spring and fall tonics can be applied to your rose bushes. Recipes for some of them can be founded at these sites:
- Rose Magazine: Spring and Fall Rose Tonic
- Spring Valley Roses: How to Grow Roses
- American Rose Society: Fertilizers: When and How
- Although general-purpose fertilizers as well as rose-specific fertilizers exist, some gardeners choose to use other ingredients.American Rose Society: A Fertilizer Primer: What's In that Rose Food? These things include:
- Manure.American Rose Society: Fertilizing with Manures
- Alfalfa or alfalfa tea.American Rose Society: The Value of Alfalfa American Rose Society: Fertilizing Roses - Alfalfa Tea
- Epsom salts.Spring Valley Roses: How to Grow Roses
- Bone Meal or rock phosphate.Spring Valley Roses: How to Grow Roses
- Fish or kelp liquid fertilizer.Spring Valley Roses: How to Grow Roses
Step 4: Watering Roses
- Roses love water and needs at least one-inch of water each week during the growing season.University of Illinois Extension: Watering, Mulching and Fertilizing Roses However, this amount can change depending on different factors. A mature rose bush can lose as much as 5 gallons of water in one day during hot or dry weather.American Rose Society: Water, and Why!
- Consistent moisture is essential. Do not allow the soil to dry out between waterings.Spring Valley Roses: How to Grow Roses
- Soak the soil using a slow-moving stream of water around the base of the plant until it reaches a depth of 8 to 10 inches.Alabama Cooperative Extension System: Growing Roses
- Water in the morning to ensure that leaves dry quickly.Alabama Cooperative Extension System: Growing Roses
- Water at the base of the plant to avoid wetting the leaves.The Gardener's Network: Rose Care and Feeding
- Roses should not be standing in water because it will rot the roots.Spring Valley Roses: How to Grow Roses
- Roses will wilt, drop leaves, grow smaller leaves or stop bloom production when they are not receiving enough water.American Rose Society: Water, and Why!
- Signs of too much water include limp and yellow leaves and leaves that fall off the bottom of the bush prematurely.American Rose Society: Water, and Why!
- Water clay soils less often than loam soils and loam soils less often than sandy soils.American Rose Society: How Often Should I Water My Roses?
Step 5: Pruning and Cutting Roses
- Pruning should be done in the spring after the danger of frost has passed because it will improve the size, quality and color of your roses.Alabama Cooperative Extension System: Growing Roses Before pruning, make sure you have a pair of sharp pruning shears and some heavy gardening gloves.
- Make all cuts about 1/4 inch above a bud that is facing the outside.American Rose Society: The Basics of Pruning
- Cut at a 45 to 50° angle.Kansas State University: Growing Roses
- First, prune any dead, damaged or weak growth.Alabama Cooperative Extension System: Growing Roses
- Next, prune any canes that cross over and rub against each other.Spring Valley Roses: Pruning Your Roses: Why, How and When
- Always remove older canes before removing newer canes. Spring Valley Roses: Pruning Your Roses: Why, How and When
- Seal your cuts with a drop of carpenter's glue, nail polish or black pruning sealer to ensure a quicker recovery.American Rose Society: The Basics of Pruning
- When you are finished, you should have removed about one-third to one-half of the volume of the plant and your rose bush should have only healthy canes with the center of the plant should be open.American Rose Society: Pruning Roses: 101
- For information on how to prune specific varieties of roses, check out any of the following links:
- Ed Hume Seeds: March is Rose Pruning Time
- Alabama Cooperative Extension System: Growing Roses
- Kansas State University: Growing Roses
- Clemson Extension: Pruning Roses
- Adams County Cooperative Extension: Pruning Roses
- University of Illinois Extension: Pruning Roses
- YouTube: How to Prune Roses with Rich Baer (Time: 6:38)
Step 6: Dealing with Pests
- Insects can be a problem with roses. Although they do not spread viruses and disease as they do on other plants, they can still leave you with damaged blooms and sickly rose bushes. Here are some of the more common pests.
Aphids
- Aphids are the most common pests on roses.University of Illinois Extension: Insect Pests of Roses They are soft-bodied insects about 1/8-inch long that vary in color from red, green, yellow or black. Aphid species vary from state to state but include the rose aphid, Macrosiphum rosae, the potato aphid, Macrosiphum euphorbiae, and the cotton aphid, Aphis gossypii.
- Aphids damage roses by sucking out the sap from their stems and buds, which can cause curling, yellowing, and distortion of leaves and stunting of shoots.UC IPM Online: Aphids Management Guidelines
- They also produce a fluid called "honeydew" which may develop a sooty mold fungus.American Rose Society: Aphids
- Early detection is essential when trying to control aphids.American Rose Society: Aphids Check your roses at least twice a week.
- Aphids have many natural enemies including ladybugs (lady beetles), soldier beetles and syrphid flies.
- Because ants feed on the honeydew excreted by aphids, they will protect them against enemies. Control ants using sticky barriers, baits, or traps.UC IPM Online: Roses: Insect and Mite Pests and Beneficials Management Guidelines
- Insecticides that contain bifenthrin, carbaryl, cyfluthrin, esfenvalerate, horticultural oil, insecticidal soap, lambda cyhalothrin, malathion, neem oil, permethrin, or pyrethrin will kill aphids.Clemson Extension: Rose Insects & Related Pests
- You can also use soil drenches or granular applications of imidacloprid, dinotefuran, or disulfoton See Table 1 for products containing these insecticides.Clemson Extension: Rose Insects & Related Pests
- Spraying plants with a mixture that is 1 part Listerine and 1 part water has been known to make plants unpalatable to aphids.American Rose Society: Rose Magazine: Rose Pests
Japanese Beetles
- Japanese beetles (Popillia japonica) is 1/2-inch long metallic green and copper brown beetles that feed on flowers, buds and leaves of roses.
- Controlling Japanese beetles can be done through various chemical and non-chemical methods.
- Many gardeners feel that Sevin provides the best control.University of Illinois Extension: Insect Pests of Roses
- Beetle traps are not recommended because they simply attract more beetles to the roses.American Rose Society: Waging War on the Japanese Beetle
- An effective method of getting rid of Japanese beetles is to treat the surrounding grassy areas with Milky Spore.American Rose Society: Waging War on the Japanese Beetle It contains a bacterium that causes a disease in grubs.
- Other insecticides that will work on Japanese beetles include bifenthrin, carbaryl, cyfluthrin, esfenvalerate, lambda cyhalothrin, malathion, neem oil, permethrin and pyrethrin.Clemson Extension: Rose Insects & Related Pests
- Soil drenches or granular applications of imidacloprid, dinotefuran, or disulfoton are better because they last longer.Clemson Extension: Rose Insects & Related Pests
Thrips
- Thrips are extremely small insects that range in color from translucent, yellowish-white, brown or black and are usually found inside blossoms. Not all thrips are necessarily bad since Western flower thrips (Frankliniella occidentalis) are a natural predator of spider mites.UC IPM Online: Roses: Insect and Mite Pests and Beneficials Management Guidelines
- Thrips cause brown streaks on blossom petals or cause petals to become distorted.UC IPM Online: Roses: Insect and Mite Pests and Beneficials Management Guidelines
- They can also feed on the upper surface of leaves.American Rose Society: Rose Magazine: Rose Pests
- Fragrant, light-colored roses are attacked more often and damaged more severely.UC IPM Online: Roses: Insect and Mite Pests and Beneficials Management Guidelines
- Cultivars with sepals that remain tightly wrapped until it blooms have less problems with thrips.UC IPM Online: Thrips Management Guidelines
- Thrips are worse when temperatures are warm during late June, July and August. University of Illinois Extension: Insect Pests of Roses
- Controlling thrips can be difficult since insecticides are most effective when thrips are still developing and hidden deep within buds and flowers.UC IPM Online: Roses: Insect and Mite Pests and Beneficials Management Guidelines
- Remove spent blooms from bushes promptly and destroy them (along with any thrips inside).American Rose Society: Thrips
- Regularly water your roses.American Rose Society: Rose Magazine: Rose Pests
- Acephate, bifenthrin, cyfluthrin, esfenvalerate, lambda cyhalothrin, permethrin and spinosad are insecticides that are known to kill thrips.Clemson Extension: Rose Insects & Related Pests
- Soil drenches or granular applications of dinotefuran, disulfoton or imidacloprid can also help control thrips.Clemson Extension: Rose Insects & Related Pests
Spider Mites
- Spider mites are extremely small relatives of spiders. To the naked eye, they look tiny red, brown or black specks.UC IPM Online: Spider Mites Management Guidelines They suck the sap out of leaves, leaving them yellowed, dried, and curled up before they fall off.University of Illinois Extension: Insect Pests of Roses
- Leaves may appear dull and the underside will feel rough.American Rose Society: Spider Mites
- Webbing can appear on the underside of leaves, which is the sign of a heavy infestation.American Rose Society: Spider Mites University of Illinois Extension: Insect Pests of Roses
- Spider mites are most problematic during hot, dry weather.American Rose Society: Rose Magazine: Rose Pests
- Chemicals can be used to control spider mites, but must be done cautiously. Mites can easily become resistant.
- Spray insecticidal soap, horticultural oil, or neem oil can be sprayed on the underside of the leaves to kill mites.UC IPM Online: Roses: Insect and Mite Pests and Beneficials Management Guidelines
- Do not use a broad-spectrum insecticide such as carbaryl.UC IPM Online: Roses: Insect and Mite Pests and Beneficials Management Guidelines It will kill off the natural enemies of spider mites and actually make the infestation worse.
- You can try applying rubbing alcohol to the affected leaves.American Rose Society: Rose Magazine: Rose Pests
- You can also use a garden hose to spray the underside of the leaves every two to three days to manage mites. This will interrupt their life cycle.University of Illinois Extension: Insect Pests of Roses
Scale
- Scales that will attack roses include armored scales such as the California red scale (Aonidiella aurantii), the rose scale (Aulacaspis rosae), the latania scale (Hemiberlesia lataniae) and the San Jose scale (Quadraspidiotus perniciosus). They also include soft scales such as the frosted scale (Parthenolecanium pruinosum), the Kuno scale (Eulecanium kunoense) and cotton cushion scale (Icerya purchasi).
- Scale insects form tiny crust-like formations that are either gray, white or tan on the stems of roses.American Rose Society: Rose Magazine: Rose Pests
- Leaves may also have a sticky honeydew substance on them when they have soft scales on them.American Rose Society: Rose Magazine: Rose Pests
- Controlling scales can be using natural enemies, pruning, and using horticultural oils or insecticidal sprays.
- Natural enemies of scales include ladybugs, lacewings, mites and parasitic wasps.UC IPM Online: Scale Management Guidelines
- If the infestation is light, you can try scraping off scales by hand and destroying them.Clemson Extension: Rose Insects & Related Pests
- Prune and destroy heavily infested canes.UC IPM Online: Scale Management Guidelines
- Horticultural oils can be applied at a rate of 3 to 4 percent during the dormant season and 1 to 2 percent during the spring to control scales. Spray when the temperature is between 40 to 85°F.Clemson Extension: Rose Insects & Related Pests
- Insecticidal sprays that are effective against young scales (known as crawlers) include: acephate, bifenthrin, cyfluthrin, esfenvalerate, lambda cyhalothrin, malathion, or permethrin.Clemson Extension: Rose Insects & Related Pests
Rose Leafhopper
- Rose leafhoppers are 1/4- to 1/2-inch long, wedge-shaped insects that vary in color from white, gray, yellow or green.Clemson Extension: Rose Insects & Related Pests
- Adults lay eggs within rose canes in the fall and hatch in the spring. The resulting wounds can lead to stem canker and other fungal diseases.Clemson Extension: Rose Insects & Related Pests
- Both adults and nymphs feed on the undersides of leaves which causes white stippling and spots.
- You may also notice cast skins and the absence of webbing on the underside of leaves.UC IPM Online: Roses: Insect and Mite Pests and Beneficials Management Guidelines
- Because they can be very difficult to control and rarely do any serious harm, most control methods are generally not recommended.UC IPM Online: Leafhoppers
- If population gets too bad, you can apply insecticidal soap or narrow-range oil.UC IPM Online: Leafhoppers
- Make sure to spray lower leaf surfaces thoroughly.
- Insecticidal sprays that are effective against rose leafhoppers include: acephate, bifenthrin, cyfluthrin, esfenvalerate, lambda cyhalothrin, malathion and permethrin.Clemson Extension: Rose Insects & Related Pests
- You can also use soil drenches or granular applications of dinotefuran, disulfoton or imidacloprid to suppress leafhopper populations.Clemson Extension: Rose Insects & Related Pests
- Avoid using broad spectrum insecticides that will kill the natural enemies of rose leafhoppers such as damsel bugs and assassin bugs.Clemson Extension: Rose Insects & Related Pests
Rose Slugs or Sawfly Larvae
- There are three types of slugss that can cause problems on roses—all are actually the larvae of sawflies.
- The roseslug, Endelomyia aethiops, is black to pale green with legs.UC IPM Online: Roses: Insect and Mite Pests and Beneficials Management Guidelines
- The bristly roseslug, Cladius difformis, is pale green with hairlike bristles over its body. It will grow between 3/8- to 5/8-inch long.Rose Magazine: Rose Slugs
- The curled roseslug, Allantus cinctus, is pastel green with white spots on its thorax and abdomen and a yellowish head with black eye spots. It will grow about 3/4-inch long.Rose Magazine: Rose Slugs
- Depending on the species, rose slugs will feed on either the upper or lower surface of the leaves between the veins and may chew large holes into the leaf.Clemson Extension: Rose Insects & Related Pests
- Rose slugs can removed using your fingers or with a strong stream of water. Once removed, they cannot climb back onto the leaves.Clemson Extension: Rose Insects & Related Pests
- Bacillus thuringiensis will not work because rose slugs are not the larvae of moths or butterflies.Rose Magazine: Rose Slugs
- You can kill rose slugs with an application of insecticidal soap or horticultural oil.UC IPM Online: Roses: Insect and Mite Pests and Beneficials Management Guidelines Clemson Extension: Rose Insects & Related Pests
- Insecticidal sprays that can be used include acephate, bifenthrin, carbaryl, cyfluthrin, esfenvalerate, lambda cyhalothrin, permethrin or spinosad.Clemson Extension: Rose Insects & Related Pests
- Spray both the upper and lower leaf surfaces and the soil under the rose bushes where the larvae pupate prior to overwintering.Rose Magazine: Rose Slugs
Other Insects
- Caterpillars: Caterpillars, which are the larvae of moths and butterflies, are occasionally seen feeding on the leaves of roses.
- They will leave irregular-shaped holes on leaves.Clemson Extension: Rose Insects & Related Pests
- Damage is rarely severe enough to warrant treatment.UC IPM Online: Roses: Insect and Mite Pests and Beneficials Management Guidelines
- You can either remove the caterpillars by hand or use insecticidal sprays such as Bacillus thuringiensis, acephate, bifenthrin, carbaryl, cyfluthrin, esfenvalerate, lambda cyhalothrin, malathion, neem oil, permethrin, pyrethrin or spinosad.
- Soil drenches or granular applications of imidacloprid, dinotefuran, or disulfoton will also work.Clemson Extension: Rose Insects & Related Pests
- Leafcutting or Leaf Cutter Bees: Leafcutting bees, also known as leaf cutter bees, are part of the Megachile species.UC IPM Online: Leafcutting Bees
- They appear similar to honeybees, but have a metallic purple or green color and are about 1/2-inch long.
- Females cut round sections out of the edges of leaves to line their nest.University of Illinois Extension: Insect Pests of Roses
- Because bees are important for pollination and they are not harming the plant, they should be tolerated rather than killed.Rose Magazine: Rose Pests
- Nematodes: Nematodes are microscopic, eel-like roundworms that live and feed on plant roots.UC IPM Online: Nematode Management Guidelines
- They can cause low plant vigor, small yellow leaves, stunting, fewer bud formations and leaves to shed early.Alabama Cooperative Extension System: Diseases of Roses and Their Control
- There are no chemicals available on the market that will control nematodes.Alabama Cooperative Extension System: Nematode Control in the Home Vegetable Garden
- Rose Midges: Rose midges (Dasineura rhodophaga) are very tiny flies that lay eggs inside the sepals of flower buds.
- When eggs hatch, the larvae feed on the flower buds, causing them to wither, blacken and die.UC IPM Online: Roses: Insect and Mite Pests and Beneficials Management Guidelines
- The rose midge has no known predators and no natural means of control.Rose Magazine: Rose Pests
- Don't confuse the rose midge with another midge, Aphidoletes aphidimyza, that feeds on aphid colonies.UC IPM Online: Roses: Insect and Mite Pests and Beneficials Management Guidelines
- Rose Galls: Rose gall is caused by a species of wasp that secretes a chemical and causes a round mass on rose canes in which it can lay its eggs.Rose Magazine: Rose Pests Pruning off affected canes should provide sufficient control.UC IPM Online: Roses: Insect and Mite Pests and Beneficials Management Guidelines
Less Common Pests on Roses Step 7: Dealing with Disease
- Dealing with disease is one of the most common problems that rose growers have to deal with. As with any problem, prevention is always better than treatment. Below you will find how to do both with some of the major diseases that affect roses.
Black Spot
- Black spot (or blackspot) is a very common problem among roses caused by the fungus Diplocarpon rosae.
- Symptoms: Small, round or irregular black spots that ranging in size from 1/16-inch to 1/2-inch in diameter. Canes may develop raised, reddish-purple spots.Virginia Cooperative Extension: Rose Black Spot
- Spots will have feathery margins and there will be no powdery growth on the undersides of the leaves.UC IPM Online: Black Spot
- The spots will be mostly on the upper surface of leaves and will yellow around the spots.Ohio State University Extension Fact Sheet: Black Spot of Roses
- Leaves eventually turn yellow and fall off prematurely.Virginia Cooperative Extension: Rose Black Spot
- Unlike other leaf spot disease, black spot has fringed margins and darker, blacker spots.Virginia Cooperative Extension: Rose Black Spot
- Causes: Fungus needs a wet environment of about 85 percent humidity with a temperature of at least 75°F.American Rose Society: Seeing Spots Before Your Eyes? If these conditions continue for over seven hours, the fungus will germinate and symptoms will appear with three to ten days.Rose Magazine: Blackspot
- It can be spread by splashing water as well as on clothing, tools and your hands.University of Illinois Extension: Disease and Insect Pests of Roses: Diseases American Rose Society: What is Blackspot?
- Miniature roses are more susceptible than other varieties of roses.UC IPM Online: Black Spot
- The fungus can overwinter on fallen leaves and stem cankers.University of Illinois Extension: Disease and Insect Pests of Roses: Diseases
- Treatment: Treatment for blackspot includes pruning and using fungicides.
- Neem oil (Triact), propiconazole (Banner Maxx), stylet oil (JMS Stylet Oil) thiophanane methyl (Cleary 3336 or FungoFlo), chlorothalonil (Daconil 2787), mancozeb (Fore, Dithane or Maneb), thiophanate methyl + mancozeb (Zyban), trifloxystrobin (Compass) and myclobutanil (Systhane) are fungicides that have been approved for treatment of black spot.American Rose Society: Seeing Spots Before Your Eyes? Virginia Cooperative Extension: Rose Black Spot
- Spray a mixture of 4 teaspoons baking soda in a gallon of water and a 1 percent solution of narrow-range horticultural oil or Neem oil.UC IPM Online: Black Spot Do not spray on blossoms.
- Remove infected canes by pruning them back to within 1 to 2 inches of the bud union in the fall or early spring.Clemson Extension: Rose Diseases
- Remove infected leaves when they appear.Clemson Extension: Rose Diseases
- One home remedy that may work is to use a solution of 1 teaspoon baking soda, 1 quart of water and a few drops of liquid soap.Rose Magazine: Blackspot Spray infected plants thoroughly.
- Prevention: Taking steps to prevent black spot is advisable since it is such a wide-spread problem.
- Plant varieties of roses with a higher resistance to black spot.University of Illinois Extension: Disease and Insect Pests of Roses: Diseases You can find lists of varieties that are resistant:
- Ohio State University Extension Fact Sheet: Black Spot of Roses
- Purdue University: Reduce Defoliation From Rose Black Spot; Plant Tolerant Cultivars (March 22, 2004)
- Virginia Cooperative Extension: Rose Black Spot
- Berkeley Horticultural Nursery: Disease Resistant Roses
- Do not wet the leaves when watering.University of Illinois Extension: Disease and Insect Pests of Roses: Diseases
- Water in the morning so the leaves have a chance to dry.UC IPM Online: Black Spot
- Plant roses in an area with good air circulation.University of Illinois Extension: Disease and Insect Pests of Roses: Diseases
- Spraying a fungicide such as triforine, chlorothalonil or phaltan may help prevent it.UC IPM Online: Black Spot Ohio State University Extension Fact Sheet: Black Spot of Roses Spray after it has rained.Rose Magazine: Blackspot
- Do not used infected plants in compost.Rose Magazine: Blackspot
- Plant varieties of roses with a higher resistance to black spot.University of Illinois Extension: Disease and Insect Pests of Roses: Diseases You can find lists of varieties that are resistant:
Powdery Mildew
- Powdery Mildew is caused by the fungus Sphaerotheca pannosa var. rosae and is a widespread and serious problem with roses.Clemson Extension: Rose Diseases
- Symptoms: White to gray fuzzy powdery growth on both surfaces of the leaves, shoots, sepals, buds, and petals.UC IPM Online: Powdery Mildew on Ornamentals Management Guidelines
- Young, expanding leaves and shoots may twist and distort or develop a purple coloration.Alabama Cooperative Extension System: Diseases of Roses and Their Control University of Illinois Extension: Disease and Insect Pests of Roses: Diseases
- Mature leaves are less likely to be affected.University of Illinois Extension: Disease and Insect Pests of Roses: Diseases
- Mildew will affect the top of the plant first.University of Illinois Extension: Disease and Insect Pests of Roses: Diseases
- Flower buds may fail to open or produce poor-quality flowers.Clemson Extension: Rose Diseases
- Causes: Powdery mildew occurs when temperatures are between 70 to 80 degrees F and the humidity is high at night but low during the day.Clemson Extension: Rose Diseases
- Worse in shady areas and during cooler periods.Clemson Extension: Rose Diseases
- Most severe during dry climatic conditions.Virginia Cooperative Extension: Powdery Mildew of Ornamental Plants
- Mildew is spread by wind.Virginia Cooperative Extension: Powdery Mildew of Ornamental Plants
- It is rarely seen during hot weather.Alabama Cooperative Extension System: Diseases of Roses and Their Control
- Treatment: Once powdery mildew is visible, it can't be eradicated.American Rose Society: Powdery Mildew: An Ounce of Prevention. . . However, there are some things you can do to limit its effects.
- Prune diseased leaves and canes during the growing season.UC IPM Online: Powdery Mildew on Ornamentals Management Guidelines
- Azoxystrobin (Heritage), Fenarimol (Rubigan), lime sulfur, Myclobutanil (Systhane), neem oil (Triact), Piperalin (Pipron), potassium bicarbonate (Kaligreen), Stylet oil (JMS Stylet Oil), Triadimefon (Strike), wettable sulfur copper hydroxide, copper salts of fatty acids, copper sulfate pentahydrate, propiconazole, thiophanate-methyl, triadimefon, triforine or triforine + acephate & hexakis are fungicides that have been approved for treatment of powdery mildew.American Rose Society: Seeing Spots Before Your Eyes? Clemson Extension: Rose Diseases
- Prevention: Preventative methods are essential when dealing with powdery mildew and must be done on a regular basis.American Rose Society: Powdery Mildew: An Ounce of Prevention. . .
- Protect new growth with a cover of fungicide.University of Illinois Extension: Disease and Insect Pests of Roses: Diseases
- Plant roses in sunny areas with good air circulation.American Rose Society: Mildew in May
- Sodium bicarbonate (baking soda) when combined with horticultural oils can control powdery mildew. Use 4 teaspoons of baking soda per gallon of water and a 1 perscent solution of narrow range oil.UC IPM Online: Powdery Mildew on Ornamentals Management Guidelines Apply early in the morning.American Rose Society: Mildew in May
- Control measures may not be needed until the drier months of late summer.Clemson Extension: Rose Diseases
- Planting varieties of roses with a resistance to powdery mildew is also a good idea. You can find lists of varieties that are resistant:
- Purdue University: Reduce Defoliation From Rose Black Spot; Plant Tolerant Cultivars (March 22, 2004)
- Virginia Cooperative Extension: Powdery Mildew-Resistant Woody Ornamentals
- Berkeley Horticultural Nursery: Disease Resistant Roses
- Alabama Cooperative Extension System: Diseases of Roses and Their Control
Downy Mildew
- Downy mildew is a fairly common problem on roses that is caused by the fungus Peronospora sparsa.American Rose Society: Diseases of Roses - Downy Mildew
- Symptoms: Downy mildew causes purple, red or dark brown spots about 1/2-inch in diameter on the leaves.
- The undersides of leaves may be covered with gray downy fungal growth.Alabama Cooperative Extension System: Diseases of Roses and Their Control
- Spots may be surrounded by a yellow halo.Alabama Cooperative Extension System: Diseases of Roses and Their Control
- Leaves may yellow and drop within two days of infection.American Rose Society: Seeing Spots Before Your Eyes?
- Symptoms will appear on the top third of the plant and move their way down the plant.American Rose Society: Seeing Spots Before Your Eyes?
- Causes: It is most common when temperatures are below 80°F and humidity is above 85 percent.American Rose Society: Diseases of Roses - Downy Mildew It can be spread by splashing water and through the air.American Rose Society: Seeing Spots Before Your Eyes?
- Treatment: Because it is often mistaken for blackspot, it is important that you have accurately diagnosed the problem before beginning a treatment.American Rose Society: Diseases of Roses - Downy Mildew
- Neem oil (Triact), dithiocarbamates (Dithane T&O and Protect), sulfur dusts azoxystrobin (Heritage 50W) and fosethyl-Al (Aliette T/O or Prodigy T/O) have been approved for the control of downy mildew.American Rose Society: Seeing Spots Before Your Eyes? Western Connection: Downey Mildew Control Alabama Cooperative Extension System: Diseases of Roses and Their Control
- You should also remove and destroy any diseased canes and leaves.Alabama Cooperative Extension System: Diseases of Roses and Their Control
- Prevention: The best way to avoid problems with fungus is to plant roses in areas with full sun.Alabama Cooperative Extension System: Diseases of Roses and Their Control
Stem Canker and Dieback
- Canker is a disease caused by a combination of stress and a type of fungi including ''Botryosphaeria, Leptosphaeria, Coniothyrium'' or ''Cryptosporella''.University of Illinois Extension: Disease and Insect Pests of Roses:
- '''Treatment:''' Prune and destroy any infected canes.West Virginia University Extension Service: Canker of Rose Make sure you disinfect your pruning shears in alcohol after each cut. Fungicides used to treat black spot and powdery m
- '''Causes:''' Canes are infected through wounds during periods of humid weather.Alabama Cooperative Extension System: Diseases of Roses and Their Control It is common on canes weakened by black spot, poor nutrition or winter inju
- '''Prevention:''' Preventing injury to your rose bushes during the winter, when pruning or flower cutting, and during cultivating and transplanting is the best way to avoid stem cankers.Clemson Extension: Rose Diseases Also
Botrytis Blight
- Botryris blight is caused by the fungus Botrytis cinerea that attacks dying tissue on rose bushes. It is also called gray mold.University of Illinois Extension: Disease and Insect Pests of Roses: Diseases
- Symptoms: First symptoms appear as small light-colored spots that are sometimes surrounded by a reddish-maroon halo that can expand into large, gray-brown, irregular blotches that cover much of the petal.American Rose Society: Seeing Spots Before Your Eyes?
- Infected buds fail to open and may droop.American Rose Society: Seeing Spots Before Your Eyes? This is similar to symptoms caused by thrips.American Rose Society: Seeing Spots Before Your Eyes? Clemson Extension: Rose Diseases
- Infected canes have discolored sunken areas and will dieback.Clemson Extension: Rose Diseases
- More frequently found on older parts of the rose bush.University of Illinois Extension: Disease and Insect Pests of Roses: Diseases
- Causes: More common during cool and rainy weather during the spring or summer when the temperature is between 62 to 72°F.Cornell University: Botrytis Blight Factsheet Clemson Extension: Rose Diseases
- Treatment: Fungicides that control black spot, such as chlorothalonil (Daconil), myclobutanil (Immunox) and thiophanane methyl (Cleary's 3336), captan and neem oil (clarified hydrophobic extract) have been effective against Botrytis blight.Alabama Cooperative Extension System: Diseases of Roses and Their Control Clemson Extension: Rose Diseases
- Other fungicides that can work include fenhexamide (Decree), fixed copper (Kocide, BlueShield, Champ), mancozeb (Dithane) and neem oil have been approved for treatment of Botrytis spp.American Rose Society: Seeing Spots Before Your Eyes?
- Use PCNB or copper sulfate pentahydrate on dormant bushes.Clemson Extension: Rose Diseases
- Prune out infected blooms, canes and buds immediately.Alabama Cooperative Extension System: Diseases of Roses and Their Control
Rust
- Rust is a disease caused by several species of species of the fungus Phragmidium that is more prevalent on the West Coast than the East Coast.Rose Magazine: Rust
- Symptoms: Small, orange, powdery pustules appear on parts of the plant starting on the underside of lower leaves.University of Illinois Extension: Common Rust of Roses
- Upper sides of leaves may discolor and the leaves turn yellow may drop.UC IPM Online: Roses: Diseases and Abiotic Disorders Management Guidelines
- In the late summer or early fall, it can appear as masses of dark brown or black spores on the leaves and stems.University of Illinois Extension: Common Rust of Roses
- Causes: Rust can develop when the temperature is between 65 to 70 degrees with continuous moisture for over two hours.Colorado State University Extension: Diseases of Roses in Colorado Rain and wind will spread spores.Rose Magazine: Rust
- Treatment: Remove and destroy any affected leaves.Rose Magazine: Rust If necessary, treat with a fungicide. Azoxystrobin (Heritage), mancozeb (Dithane), myclobutanil (Systhane), propiconazole (Banner Maxx) and triadimefon (Strike) ferbam, and lime sulfur are fungicides that have been approved for treatment of rusts.American Rose Society: Seeing Spots Before Your Eyes? Clemson Extension: Rose Diseases
- Prevention: With nine different varieties of rust that can infect roses, prevention can be difficult.
- Plant varieties of roses with a resistance to rust. To find lists of rose varieties that are resistant to rust check out:
- Purdue University: Reduce Defoliation from Rose Black Spot; Plant Tolerant Cultivars (March 22, 2004)
- Berkeley Horticultural Nursery: Disease Resistant Roses
- University of Illinois Extension: Common Rust of Roses
- Colorado State University Extension: Diseases of Roses in Colorado
- Destroy any wild or uncared-for roses that are nearby.
- Make sure there is good air circulation around the plants.University of Illinois Extension: Common Rust of Roses
- Water before noon and make sure the leaves do not get wet.Clemson Extension: Rose Diseases
- Use fungicides as a preventative.UC IPM Online: Roses: Diseases and Abiotic Disorders Management Guidelines
- Plant varieties of roses with a resistance to rust. To find lists of rose varieties that are resistant to rust check out:
Other Diseases
- Crown Gall: Crown gall is caused by a soil-inhabiting bacteria Agrobacterium tumefaciens that invades rose plants thorough wounds.UC IPM Online: Roses: Diseases and Abiotic Disorders Management Guidelines
- It causes shaped, rough, dark-colored masses (known as galls) to appear on stems near the soil line.University of Illinois Extension: Disease and Insect Pests of Roses: Diseases
- Once a rose plant is infected, nothing can be done to treat it.Clemson Extension: Rose Diseases Destroy any infected plants.Colorado State University Extension: Diseases of Roses in Colorado
- For more information, check out one of the following links:
- Alabama Cooperative Extension System: Diseases of Roses and Their Control
- Virginia Cooperative Extension: Crown Gall of Woody Ornamentals
- UC IPM Online: Crown Gall
- Anthracnose or Spot Anthracnose: Anthracnose is caused by a fungus and not very common.
- Symptoms include small, red or purple, round leaf spots that are less than 1/4 inch in diameter that may have dark red margins. The center of the spot may drop out (known as a "shot-hole" effect).Colorado State University Extension: Diseases of Roses in Colorado
- Hybrid teas, old-fashioned climbing and rambler roses are most susceptible. affected.UC IPM Online: Roses: Diseases and Abiotic Disorders Management Guidelines
- Fixed copper (Kocide, BlueShield, Champ), Neem oil (Triact) are fungicides that have been approved for the treatment of anthracnose.American Rose Society: Seeing Spots Before Your Eyes?
- Rose Rosette Disease: Rose rosette disease is caused by either a virus or virus-like pathogen that is spread through grafting or by an eriophyid mite to susceptible roses.Virginia Cooperative Extension: Rose Rosette Disease Penn State Weed Management: Rose Rosette Disease
- Infected canes sprout thick clusters of stubby, soft and brittle stems with small, distorted leaves that may have a conspicuous red pigmentation.American Rose Society: Watch Out for Rose Rosette Virginia Cooperative Extension: Rose Rosette Disease Flowers may be distorted or an abnormal color and have fewer petals than normal.Virginia Cooperative Extension: Rose Rosette Disease
- There is no practical way to manage it in susceptible roses.Virginia Cooperative Extension: Rose Rosette Disease
- Using the insecticide dimethoate (Cygon) to kill the mite that spreads it has been successful at preventing it. Other insecticides have been ineffective.American Rose Society: Watch Out for Rose Rosette
- Cercospora Leafspot: Very little is known about Cercospora leafspot, but it seems to have similar characteristics to black spot especially when it comes to how it is spread and treated.American Rose Society: Cercospora Leafspot in Roses
- Symptoms include tiny maroon to purple oval spots scattered long the surface of the leaves. The center of the spots may turn tan or gray and leaves may turn yellow and drop.Alabama Cooperative Extension System: Diseases of Roses and Their Control
- Many varieties of roses that are resistant to Cercospora leaf spot are susceptible to Blackspot.American Rose Society: Cercospora Leafspot in Roses
- Chlorothalonil (Daconil), fixed copper (Kocide, BlueShield, Champ), mancozeb (Dithane), Neem oil (Triact), propiconazole (Banner Maxx), triadimefon (Strike) and Myclobutanil (Systhane) are fungicides that have been approved for the treatment of Cercospora leaf spot.American Rose Society: Seeing Spots Before Your Eyes?
Step 8: Winter Care for Roses
- If you live in an area where the temperature goes below 5°F in the winter, you will need to protect your roses.All-America Rose Selections: Winter Protection There are various methods this can be used. The most common is to mound or pile up soil around the plant:
- After the first hard frost, prune back the rose plants until they are about 24 inches long.All-America Rose Selections: Winter Protection
- Tie the canes together with twine.All-America Rose Selections: Winter Protection
- Place an 8 to 12 inch mound of loose soil or compost around the base of the plant.All-America Rose Selections: Winter Protection
- You can add an additional layer of hay, evergreen boughs, hardwood leaves or straw if desired after the mound has frozen.University of Illinois Extension: Winter Protection of Roses
- Remove the mound when spring arrives.The Gardener's Network: Winter Protection For Roses
- If you live in an area that experiences extreme cold, you may want to take further methods of protecting your roses. There are various methods that you can use. For further information, check out any of the following links:
- American Rose Society: Winterizing Roses in the North Central District
- University of Illinois Extension: Winter Protection of Roses
- American Rose Society: Winter Protection in New York
Conclusion
- Now that you have the basics of rose growing down, you may want to check out Mahalo's page on How to Arrange Flowers Of course, you could also give them to that special someone. If you don't have a special someone, check out Mahalo's pages on How to Date Online, How to Flirt or How to Have a Perfect First Date.
