Pests & Diseases

Home Back About the ORS Best Roses ORS Calendar Resources Species Roses Garden Residents Articles

 

 
2014 new balenciaga arena shoes Balenciaga Arena Low Top Balenciaga Arena Low Top Creased Leather Shoes 2014 Balenciaga Cotes Monochrome red replica Balenciaga Cotes Monochrome high top Shoes Balenciaga Cotes Monochrome Red Shoes Discount balenciaga Hologram-Panelled balenciaga Hologram Panelled High Top 2014 Balenciaga Hologram-Panelled black replica balenciaga Hologram-Panelled shoes review Super Perfect Balenciaga Cambure Panelled Pleated Leather 2014 Balenciaga Cambure Panelled Pleated black replica Balenciaga Pleated high top Shoes Balenciaga Arena White&Black On-foot Review 2014 replica balenciaga shoes on foot review newest replica balenciaga men shoes on-foot review 2014 new balenciaga arena shoes Review Black Beats by Dr. Dre Mixr DJ Headband Headphones by Dr. Dre Mixr Review DJ Headband Headphones by Dr. Dre Mixr Beats by Dr. Dre Mixr for DJs Giuseppe Zanotti High Top sneakers Black Suede Giuseppe Zanotti High Top Replica Men's Giuseppe Zanotti High Top Suede Spring 2014 Giuseppe Zanotti High Top Suede Men Shoes Giuseppe Zanotti Double Zipper High Top sneakers Fashion Mens GIUSEPPE ZANOTTI Metallic Blue discount Giuseppe Zanotti Double Zipper High Top Replica Men's Giuseppe Zanotti High Top Double Zipper Spring 2014 Giuseppe Zanotti Double Zipper Sneakers Mens GIUSEPPE ZANOTTI Brown Suede and neon orange Mens GIUSEPPE ZANOTTI Brown Double Zipper shoes Brown/neon orange Giuseppe Zanotti shoes discount Giuseppe Zanotti Croc White high top shoes review Giuseppe Zanotti Croc Double-Zip shoes Mens Giuseppe Zanotti Crocodile sneakers black Giuseppe Zanotti zipper sneakers Giuseppe Zanotti Black Velvet Leather High-top spring 2014 Giuseppe Zanotti High-top zipper shoes BUSCEMI 100MM Buscemi Birkin 18K shoes BUSCEMI Full Grain Italian leather High Top Shoes Coda neon green leather sneaker Gucci Neon green high top men shoes 2014Gucci Neon green high top men shoes discount Balenciaga white high top cheap balenciaga high white sneakers Balenciaga Arena Creased Navy Blue Balenciaga Arena Navy Blue men shoes rick owens for adidas 2014 spring collection rick owens x adidas runner review adidas x rick owens men shoes discount rick owens x adidas runner shoes White Giuseppe Zanotti High Top sneakers Replica Men's Giuseppe Zanotti High Top Suede Spring 2014 Giuseppe Zanotti High Top Suede Men Shoes cheap Giuseppe Zanotti High Top Suede men shoes super perfect Guiseppe Low Top Shoes Low giuseppe zanotti black sneakers Giuseppe Patent Low top sneakers in black Giuseppe Zanotti Side Zip Sneakers buscemi 100mm leather high-tops jon buscemi shoes buscemi spring 2014 for men buscemi 100mm birkin giuseppe zanotti sneakers unboxing giuseppe zanotti sneakers on feet giuseppe zanotti sneakers for men high-top giuseppe zanotti sneakers Balenciaga Arena navy blue men shoes Balenciaga Arena high top shoes review cheap balenciaga high navy blue sneakers Balenciaga Arena Creased Navy Blue Balenciaga white shoes white-yellow sole cheap balenciaga high white sneakers discount Balenciaga white high top Balenciaga Arena Creased white review cheap balenciaga pleated blue shoes Balenciaga Cambure Panelled Pleated Leather balenciaga Panelled Pleated High Top 2014 Balenciaga Pleated blue replica balenciaga Pleated red shoes review cheap balenciaga pleated Red shoes 2014 Balenciaga Pleated red replica Discount Pleated red balenciaga Cheap Balenciaga Arena Creased Leather Balenciaga Arena high top shoes discount Balenciaga Arena high top 4colors balenciaga arena creased men shoes balenciaga arena black replica 2014 new released balenciaga arena shoes Balenciaga Arena Creased Black Balenciaga Arena Black men shoes 2014 Balenciaga Cotes Monochrome Black replica discount Balenciaga Cotes Monochrome Shoes Balenciaga Cotes Monochrome high top Shoes Black Balenciaga Cotes Monochrome Shoes review Balenciaga Arena Low Top discount Balenciaga Arena Shoes Balenciaga Arena Low Top Creased Leather Shoes 2014 new mens Giuseppe Zanotti white sneakers 2014 fashion Giuseppe Zanotti croc high top shoes fashion Giuseppe Zanotti high top white shoes on sale Giuseppe Zanotti Croc White high top Lace up Giuseppe Zanotti High Top Black Leather Replica 2014 new mens Giuseppe Zanotti black sneakers 2014 fashion Giuseppe Zanotti Black Velvet Leather High-top Sneakers fashion Giuseppe Zanotti high top black shoes on sale Gucci Neon green Sneaker online review Coda neon green leather sneaker Gucci Neon green high top men shoes Gucci Neon green high top men sneakers Giuseppe Zanotti black high top replica Giuseppe Zanotti zipper high top sneakers review 2014 new mens Giuseppe Zanotti black sneakers higher quality Giuseppe Zanotti black sneakers cheap Balenciaga Arena Black shoes 2014 new balenciaga arena shoes Balenciaga Arena Low Top Balenciaga Arena Low Top Creased Leather Shoes fashion giuseppe zanotti black high-top shoes review 2014GIUSEPPE ZANOTTI zipper high top shoes GIUSEPPE ZANOTTI high top men shoes Giuseppe zanotti high top black leather sneakers Air Jordan XI Retro Space Jam Men Shoes review Authentic quality Air Jordan 11 Retro Space Jam Men Shoes Jordan XI Retro Space Jam review Gucci High-top White Shoes with Gucci Stripe fashion Gucci High-top White Sneakers online review Review Gucci High-top Lace-up White Shoes Balenciaga Arena white men shoes discount Balenciaga white high top Balenciaga Arena Creased white replica review review cheap Balenciaga Arena black shoes discount Balenciaga Arena Shoes review Balenciaga Arena Low Top Creased Leather Shoes 2014 replica balenciaga men shoes review review Balenciaga Arena Low Top fashion Giuseppe Zanotti zipper shoes spring 2014 Giuseppe Zanotti Low-top zipper shoes fashion Giuseppe Zanotti Double Zipper shoes Giuseppe Zanotti low-top sneakers Giuseppe Zanotti black low top replica spring 2014 Giuseppe Zanotti Low-top shoes black and white Giuseppe Zanotti low top mens Giuseppe Zanotti low top sneakers Giuseppe Zanotti low top zipper sneakers Zanotti Low-top zipper shoes new Giuseppe Zanotti black Low-top zipper shoes review Giuseppe Zanotti black low top sneakers 2014 Balenciaga Cotes Monochrome red replica Balenciaga Cotes Monochrome high top Shoes Review Balenciaga Cotes Monochrome Red Shoes Balenciaga Arena Low Top Creased Shoes discount Balenciaga Arena Shoes Review Balenciaga Arena Low Top 2014 new balenciaga arena shoes Review Balenciaga Arena White shoes 2014 replica balenciaga Arena review newest released adidas x rick owens runner high fashion adidas x rick owens shoes discount rick owens x adidas runner shoes Balenciaga Arena Navy Blue men shoes cheap balenciaga high white sneakers Balenciaga Arena Creased Navy Blue Super Perfect Balenciaga Pleated men shoes Balenciaga Pleated high top Shoes 2014 Balenciaga Cambure Panelled Pleated black replica 2014 replica balenciaga men shoes discount Balenciaga Arena Shoes On-foot Review On-foot Review cheap Balenciaga Arena shoes Beats by Dr. Dre Mixr for DJs Beats by Dr. Dre Mixr DJ Headband Headphones by Dr. Dre Mixr Balenciaga Hologram-Panelled high top Shoes 2014 Balenciaga Hologram-Panelled black replica Super Perfect Balenciaga Hologram-Panelled cheap Giuseppe Zanotti High Top Suede men shoes discount Giuseppe Zanotti High Top Zipper Spring 2014 Giuseppe Zanotti High Top Suede Men Shoes Fashion Mens GIUSEPPE ZANOTTI Metallic Blue cheap Giuseppe Zanotti High Top Suede men shoes Review Giuseppe Zanotti Double Zipper High Top sneakers 2014Gucci Neon green high top men shoes review Gucci leater high top sneaker green Gucci high top men shoes new Giuseppe Zanotti double zipper shoes online review Brown Suede Double Zipper High Top GIUSEPPE ZANOTTI Spring 2014 Giuseppe Zanotti High Top Sneakers discount Giuseppe Zanotti Croc White high top shoes Giuseppe Zanotti Croc White Double-Zip Mens Giuseppe Zanotti White high top shoes Fashion Side Zip Giuseppe Zanotti Sneakers Giuseppe Patent Low top sneakers in black Low giuseppe zanotti black sneakers Super Perfect Buscemi 100mm Birkin 18K BUSCEMI Full Grain Italian leather High Top Shoes cheap Buscemi Birkin 18K shoes Giuseppe Zanotti Black Velvet Leather High-top new Giuseppe Zanotti Black High-top zipper shoes spring 2014 Giuseppe Zanotti High-top zipper shoes cheap Giuseppe Zanotti High Top Suede men shoes Spring 2014 Giuseppe Zanotti High Top Suede Replica Spring 2014 Giuseppe Zanotti High Top Suede Men Shoes Replica Men's Giuseppe Zanotti High Top Suede newest replica high top creased balenciaga discount Balenciaga Arena Shoes 2014 new balenciaga arena shoes 2014 replica balenciaga review fashion giuseppe zanotti black high-top shoes review Giuseppe zanotti high top black leather sneakers 2014GIUSEPPE ZANOTTI zipper high top shoes discount Gucci High-top White Shoes review fashion Gucci High-top White Sneakers online review 2013 Gucci High-top White Shoes with Gucci Stripe fashion Authentic Air Jordan 11 Space Jam Men Shoes Authentic AJ11 Retro Space Jam Shoes review review Air Jordan 11 XI Retro Space Jam Men Shoes GIUSEPPE ZANOTTI Hi Top Black Leather London Men's Sneakers Giuseppe Zanotti black Grained Leather Sneakers Mens High Top Sneaker Black Giuseppe Zanotti With Chain Double-Zip Extra White Balenciaga Arena High Sneakers Balenciaga Arena High Trainers where to buy balenciaga fake arena sneakers Super Air Jordan 6 VI Retro Oreo White Black Carmine Men's Shoes Air Jordan 6 VI Retro Oreo air jordan 6 carmine men shoes Balenciaga high top hologram shoes Balenciaga Hologram-Panelled High Top Men Sneakers high top Balenciaga Hologram shoes Balenciaga panelled men shoes Balenciaga Cambure Panelled Pleated Leather balenciaga Pleated blue shoes review review balenciaga Pleated blue shoes Balenciaga Cambure Panelled Pleated Leather cheap balenciaga pleated Red shoes 2014 Balenciaga Pleated red replica discount Balenciaga Arena high top 2014 new released balenciaga arena shoes Balenciaga Arena high top shoes Balenciaga Arena Creased Black shoes discount Balenciaga Black high top Balenciaga Arena high top shoes fashion balenciaga new shoes white 2014 Balenciaga Arena white shoes cheap balenciaga high white sneakers cheap balenciaga high navy blue sneakers Balenciaga Arena navy blue men shoes 2014 Balenciaga Arena Navy blue shoes fashion balenciaga new shoes white Balenciaga Arena Creased Leather 2014 Balenciaga Arena white shoes 2014 Balenciaga Cambure Panelled Pleated black replica balenciaga Panelled Pleated High Top Balenciaga Pleated high top Shoes Black balenciaga Sneakers review Balenciaga Arena Low Top Creased Leather Shoes Balenciaga Arena Low Top Balenciaga Arena Low Top Balenciaga Arena Low Top Creased Leather Shoes White balenciaga Sneakers review GIUSEPPE ZANOTTI White crocodile effect hi-top trainers kanye west white Crocodile giuseppe zanotti shoes Giuseppe Zanotti High Top white croc Sneakers Buckled Double Zip Giuseppe Zanotti Black Velvet Gold Bar Sneakers Giuseppe Zanotti Black Velvet Leather High-top sneakers Giuseppe Zanotti Men Black Velvet Buckled Veronica Sneakers Rick Owens x Adidas Rick Owens shoes adidas Rick Owens shoes Rick Owens x Adidas balenciaga panelled balenciaga hologram balenciaga sneakers arena balenciaga arena high sneakers balenciaga high top mens balenciaga sneakers balenciaga sneakers for men balenciaga sneakers for sale men giuseppe zanotti shoes Giuseppe calfskin leather shoes men giuseppe zanotti sneakers Balenciaga Paneled High Top Sneakers balenciaga hologram high top clear balenciaga men sneakers hologram balenciaga shoes balenciaga hologram trainers balenciaga sneakers men balenciaga hologram low top balenciaga men shoes balenciaga panelled leather sneakers Balenciaga Hologram Paneled High Balenciaga sneakers High Balenciaga's panelled sneakers Balenciaga Cotes Monochrome RED balenciaga pleated red balenciaga pleated sneaker buscemi 125mm shoes Jon buscemi 125mm high top sneakers buscemi 2014 125mm red sneakers Maison Martin Marginal sneakers MMM men sneakers Marginal black leather line 22 men shoes BEST SNEAKER QUALITY Buscemi 125mm 2014 buscemi 125mm high top sneakers Men buscemi 125mm shoes perfectkickz Maison Martin Margiela shoes Maison Martin Margiela white patern leather sneakers MMM line 22 high top sneakers perfectkickz unboxing Maison Martin Margiela shoes unboxing buscemi 125mm shoes unboxing

This will help you identify solutions for Fungus Diseases, Unwelcome Guests, and Other Problems.

Note: A good rose reference book with pictures will greatly assist your identification of rose problems. This information is offered as a general guideline for the south Puget Sound area. This material has been adapted from the Time Magazine Book, How to Grow Roses, pages 94 - 97.

There are no cures for most rose diseases.  Fungal diseases in particular must be prevented.  Fungicides cannot cure infected plants, but only stop the spread of fungal diseases.  That is why we recommend a preventative fungicide program, beginning as soon as leaves appear in spring. If you're very good, and keep up the fungicides through spring, you might be able to cut out spraying over the summer when the weather dries.  Blackspot in particular needs water on the leaves to germinate, although powdery mildew needs simply humidity and does not germinate well in free water.  That's why blackspot shows up in spring, but powdery mildew not til summer.

 

Fungus Diseases

Problem/Symptom Cause Solution
Circular black spots 1/4 inch in diameter appear on upper leaf surfaces. Each black spot has a feathery margin and is surrounded by a yellow halo. As the spots enlarge and coalesce, the entire leaf turns yellow and falls from the plant.  Purplish or brownish spots and streaks may appear on canes.

Blackspot on leaves

Blackspot on leaves

Blackspot. This fungus disease is most common in humid and rainy conditions; the fungus spores germinate in water. Once a plant is infected, the fungus will remain in the canes through the winter and reappear on the next season's growth. VERY common in the Pacific Northwest. There is no chemical cure for infected plants.  Plan on spraying with fungicides on a regular  basis to prevent infections. Prune out affected canes in your early spring pruning, and apply a fungicide before the leaves open. To prevent blackspot from infecting new plants, spray with a fungicide as soon as leaves appear in spring, and repeat according to label directions.  If symptoms appear, remove and destroy all infected leaves, including those on the ground. Do not water plants from above; wet leaves are hospitable to germinating spores.
Leaves, especially new leaves, become twisted or curled and are covered with a white powder. Flower buds and canes may also be affected.

Powdery Mildew

Powdery mildew, a fungus disease carried by wind. The problem is most severe when nights are cool and humid, and days are warm and dry. Remove and destroy all infected leaves, including those on the ground.  You will probably only have one or two varieties of roses that are susceptible to powdery mildew. To prevent mildew or to arrest its spread, spray with a fungicide starting in early summer.
Small red, brown or purple spots develop on upper leaf surfaces. The center of each spot eventually dries out, turns white and may fall out of the leaf. Leaves eventually turn yellow and fall from the plant.

Anthracnose spots on leaf

Spot anthracnose, a fungus disease. The fungus spreads in water.  This disease is somewhat similar to blackspot in appearance but appears in cool early spring weather, where blackspot needs warmer, late spring weather. Regular preventative fungicide applications for blackspot will be the best you can do for anthracnose.  Do not water plants from above, since the fungus spreads in splashing water.
Rosebuds fail to open and are covered with a grayish brown, fuzzy mold. Open flowers are flecked with yellow or brown and lower petals are wilted and brown. The stems below infected flowers become discolored.

Botrytis blight on flower

Botrytis blight, also called gray mold, a fungus disease that spreads in moist air and cool temperatures.  It can be widespread in spring, and often appears on mail-order roses that have been kept in a dark damp box during shipping. There are no chemical cures for blight once it occurs. If symptoms appear, cut off and destroy all infected plant parts. Spray with a fungicide to keep the disease from spreading.
Red or brown sunken spots with dark margins develop on canes. Cracks may appear within the spots. The spots enlarge and eventually encircle the cane. Leaves and stems above the damaged area turn yellow, wilt and die. Canker, a fungus disease. The fungus spreads in water and enters the plant through cuts or wounds in the canes. The problem is most severe in early to middle spring, when plants come out of dormancy. There is no chemical preventive or cure for canker. When symptoms appear, prune infected canes below the canker. Use sharp pruning shears and make the cut just above a node at a 45 degree angle.
An orange, powdery substance appears on the undersides of the leaves. Eventually, yellow or brown spots appear on upper leaf surfaces. Infected leaves may wilt or curl.

Rust

Rust, a fungus disease that spreads in moist air and moderate temperatures. The problem is most severe in the Pacific Northwest, where the climate is cool and humid. Remove and destroy all infected leaves, including those on the ground. Avoid overhead watering because the fungus spreads in water.  Rust prefers plants growing in hot, dry, nutrient-deficient soils, and is not common in the Olympia area.
Black patches appear on upper leaves, then spread to rest of the plant.  Unlike blackspot, these spots are angular or squared-off, stopping at leaf veins, and don't have a yellow halo.  Leaves fall off within a few days of patches appearing.  There may be long black streaks on the canes.

Downy mildew

 

Downy mildew, a fungal disease that is not at all common in the Puget Sound area, but does show up once in a great while.  Spray damage can look similar - blackened or browned patches on the upper surfaces of the leaves, but the leaves don't fall off.

If you think you might have downy mildew, call one of our Consulting Rosarians for a confirmation before embarking on control measures.

Prune out and destroy (don't compost!) all affected parts of the plant.  Spray remaining plants with Stature, Subdue, or Alliette.  You will probably have to get these mail-order.  Follow label directions to the letter.  Do not add anything else to the spray mix.  Downy mildew can kill a rose plant within weeks so act fast.  You may want to simply dig out and burn the affected plants.  Clean all tools before using on unaffected plants.

nike air max nike air max 1 nike air max 1 Canada nike air max 2012 nike air max 2013 nike air max 2014 nike air max 90 nike air max 90 Canada nike air max 95 nike air max Canada nike Canada nike Canada online nike Canada sale nike Canada store nike free 3.0 nike free 4.0 nike free 5.0 nike free 5.0 Canada nike free 5.0 womens nike free 5.0 womens Canada nike free Canada nike free run nike free run 2 nike free run 2 Canada nike free run 3 nike free run 3 womens nike free run 5.0 nike free run 5.0 womens nike free run Canada nike free run womens nike shoes Canada nike shoes Canada online nike air max 90 nike air max 90 Canada nike air max 95 nike air max thea nike air max 90 nike air max 90 Canada nike air max 2013 nike air max 2013 Canada nike air max womens nike Canada online nike Canada store nike free 3.0 nike free 4.0 nike free 5.0 Canada nike free 5.0 womens nike air max 95 nike air max 90 nike air max 2013 Nike Air Max 1 Mens nike Canada online nike Canada store nike free 3.0 nike free 4.0 nike free 5.0 nike free 5.0 Canada nike free 5.0 womens nike free run 2 Nike Air Presto Nike Air Presto Nike Air Max 1 Womens Nike Air Max 95 Womens Nike Air Max 90 Womens Nike Free 3.0 Mens Nike Free 5.0 Mens Nike Roshe Run Nike Air Max 1 Nike Air Max 95 Nike Air Presto Nike Free 5.0 Nike Free 4.0 V2 Nike Free 3.0 V4 Nike Free 3.0 V5 Nike Free 4.0 V3 Nike Free Trainer Nike Roshe Run womens Nike Free 3.0 V2 Nike Free 5.0 Mens Nike Free 5.0 Womens Nike Free 4.0 V2 Nike Free 3.0 V4 Nike Free Run 2 Nike Free 5.0 V4 Nike Free 3.0 V5 Nike Free 4.0 V3 Nike Free 3.0 V2 nike free 5.0 nike free 5.0 Canada Michael Kors Canada Michael Kors Outlet Michael Kors Online Cheap Michael Kors Handbags Michael Kors Handbags Cheap Michael Kors Michael Kors Sale michael kors outlet online michael kors outlet canada michael kors outlet handbags michael kors canada outlet michael kors handbags canada michael kors handbag michael kors bags outlet cheap michael kors bags michael kors outlet handbags canada michael kors handbags outlet michael kors outlet store michael kors canada outlet michael kors handbags canada michael kors handbag michael kors bags outlet michael kors online outlet michael kors factory outlet michael kors wallet michael kors bags on sale Michael Kors Outlet Michael Kors Online Cheap Michael Kors Handbags Michael Kors Handbags Cheap Michael Kors Michael Kors Sale michael kors outlet online michael kors outlet canada michael kors outlet handbags cheap michael kors bags michael kors outlet handbags canada michael kors handbags outlet michael kors outlet store michael kors canada outlet

Unwelcome Guests

 
Problem/Symptom Cause Solution
Leaves curl, rosebuds and foliage wither or become distorted in shape. A clear, sticky substance that attracts ants appears on foliage. Aphids, semitransparent insects 1/8 inch long that cluster on new growth and flower buds. They suck the juice from the plant and secrete the sticky substance. Aphids can carry and spread diseases. Aphids may be knocked off plants with a stream of water. In severe infestations, spray with an insecticide or an insecticidal soap.
Small, rounded holes appear in leaves. Eventually, the entire leaf surface between the veins disappears.

Rose slugs, the larvae of sawfly wasps. The slug is light green with a dark brown head and up to 1/2 inch long. Some species have shiny bodies; others are covered with hair. Rose slugs generally feed on the undersides of leaves; they do not eat buds and flowers. Spray with a systemic insecticide and make sure the insecticide covers the undersides of leaves.
Buds do not open, or flowers are deformed. Petals have brownish yellow streaks and small dark spots or bumps. White and pastel roses are particularly susceptible. Thrips, tiny orange insects with elongated bodies. Thrips feed at the bases of rosebuds and on the petals of open flowers. They seem to be attracted to light-colored blossoms. To discourage thrips from attacking, spray plants with a systemic insecticide just before the buds open. If signs of thrip damage appear, remove and destroy infected flowers and buds. Spray infected plants with an insecticide. If the infestation is severe, repeat applications may be necessary.
Roses fail to blossom or existing buds suddenly turn black and die. The foliage and the stem surrounding affected buds may also blacken and die.

Rose midge, a fly larva that is white and 1/12 inch long. The larvae feed in clusters at the bases of rosebuds. A soil-applied insecticide applied to the ground around the plants is your best bet.  Imidacloprid is the most widely recommended insecticide.  Foliar sprays won't help, since the midge spends most of its 2 week long life either in the soil or deep inside rose buds.
Leaves become dry and have a bronze sheen. Tiny specks may be visible on the undersides of the leaves. Eventually, thin webbing appears on the foliage.

Spider mites on leaf

Spider mites on underside of leaf

Spider mites, nearly microscopic pests that may be red, black, yellow or green. To confirm their presence, shake a leaf over a piece of white paper; the mites will be visible moving against the white background. Mites proliferate in hot, dry weather. Knock adults off plants with a strong stream of water.  Most infestations can be controlled with regular showers of water.  Only if that doesn't work, spray with a miticide three times, three days apart. Use different miticides; mites may build up resistance to a single miticide. Mites produce new generations in a few days, so repeat treatments will be necessary.

Avoid insecticide use, as insecticides kill the beneficial insects that keep mites under control.  Reducing reflected heat will go a long ways to preventing mite infestations - use cool mulches, underplantings of low-growing annuals and perennials, or  use overhead sprinklers and hose down surrounding hard surfaces in hot weather.

Small circles or ovals appear in leaf margins. Leafcutter bees, which are shiny black, blue or purple bees. The bees do not eat the foliage; they use leaf material to build their nests. Prune out canes that have damaged foliage. Since leafcutter bees are pollinators of several crops, the use of chemicals to destroy the bees is not recommended.
Round or oval masses appear on stems and canes. Foliage wilts, turns yellow and drops from the plant. Growth is stunted and flowers are not produced. Rose scales, 1/8-inch, white, gray or brown insects with crusty shells. Scales usually appear in clusters. Prune out and destroy heavily infested canes. To prevent scale infestation, spray plants with horticultural oil in early spring.
Holes appear in unopened rosebuds. Leaves and stems may also have holes or may be chewed off.

Caterpillar damage

Caterpillars, the larvae of moths and butterflies. Most are yellow or green and up to 1 inch long. Some, such as budworms, attack only the flowers; others eat the leaves and stems. Spray with Bacillus thuringiensis, called Bt, a bacterium fatal to caterpillars but harmless to plants and other animals.
Upper surfaces of leaves are covered with small yellow specks. Leaves may curl.

Leafhopper damage

Leafhoppers, which are triangular, white or light yellow insects 1/8 to 5/8 inch long. They feed on the undersides of leaves and suck the sap from the foliage. Leafhoppers can carry and spread diseases. Spray with an insecticide or insecticidal soap. In the fall, rake up leaves and remove weeds that can harbor leafhopper eggs through the winter.

Rosebuds have holes drilled in them, or unopened bud falls over after something drills a hole in the stem right below the bud.

Rose curculio weevil damage on flower

Rose curculio.  Curculio weevils chew on rose buds. Annoying, but whaddya gonna do. Usually they are very small, dark reddish weevils, with a long dark snout. Hand pick these small weevils.  Hold a largemouth jar full of soapy water below the weevils as they will drop to the ground at the slightest disturbance.
Leaves and flowers have angular holes chewed from the edges.

    

Root weevils.  There are a couple of species whose adults will chew on flowers as well as leaves, such as the raspberry bud weevil and clay-colored weevil, and the Fuller rose beetle in Oregon. And of course the ubiquitous black vine weevils that decimate rhodies can also chew on rose roots and leaves. Hand pick the weevils (usually gray), or dust with carbaryl or Spinosad.  Some slug control products include one of these for soil insects.  Larvae feed on roots, so treat the soil too.
Growing tips, foliage and canes wilt. Swollen areas up to 1 inch long appear on canes. Borers, moth larvae that are white or yellow worms up to 1 inch long. Borers enter the canes through wounds and through pruned stem tips. Cut off the affected area. Make the cut below the swelling on the cane to be sure you remove the borer. To prevent borers from entering canes, apply shellac or white glue to the exposed tips after pruning.
Overnight, roses are chewed and trampled.  Buds and blooms are damaged the most.  Buds and new growth may appear to have been clipped off with pruners. Deer See "Deer Control Methods" (Word Doc) for help.

Other Problems

Problem/Symptom Cause Solution
Round growths about 2 inches in diameter appear at the base of the plant. The growths are light green when young and turn brown and woody as they age. Plant growth is stunted, foliage is abnormally small and few buds are produced.

Crown gall

Crown gall, a disease caused by bacteria that live in the soil. The bacteria enter a plant through the roots or through wounds at the root area. The bacteria cause abnormal cell growth, which produces the galls. There are no chemical controls for crown gall. Small galls may be pruned out with a sharp knife or pruning shears. Disinfect tools with alcohol or household bleach after each cut. In severe cases, remove the plant and the soil surrounding the roots to prevent the bacteria from spreading.
Leaves are mottled or streaked with yellow or the develop a pattern of yellow netting. Plant growth slows, flowers may be few and/or small.

Rose mosaic virus

Virused leaves

Mosaic, a virus disease. Although the virus does not affect flowers, it detracts from the overall health and appearance of the plant. There are no chemical controls or cures. In mild cases, symptoms often disappear by themselves. In severe cases, infected plants should be removed.
Leaf margins are brown and crispy.  Weather has been hot.

Heat damage on leaves

Heat damage. Give the plants more water.
Canes turn brown inside and out.  New growth may appear, but soon shrivels and dies.

Winter-killed canes

Winter-killed canes

Winter freeze damage. Prune out damaged canes.

 

 

?/font> 2008,  The Olympia Rose Society . This page last modified:  Saturday, November 12, 2011