I have over 15 rose bushes and 1 and maybe a half of one have white stuff on the leaves. how do I treat?

Question

The leaves on two of my bushes have white stuff on them and they look like they are dying. what is this and how do I treat it?

Answer 1

That sounds like Powdery Mildew, You can make a home remedy of baking soda and water, 1 tablespoon baking soda to 4 cups of water and be diligent every couple of days go out and spray!
Or you can buy BAYER Rose and Shrub disease and insect control and water it in the ground. Then it will climb systemically through the plants system and protect the roses against several diseases and insects! Also, just get Safer Soap at the store and spray as often as you do the Baking Soda mix until ALL the Spores are dead.

Answer 2

Yes you can, but transplant, as you say, may not be the correct word. I've heard long ago that you can cut a bare spot into a branch of a live rose bush and bond the branch of the broken one you have onto the live one and, with proper care, the branch will grow into and become a part of the one you attached it to. I live near what we call The Rose Capital of Texas (Tyler, Texas) and I'm SURE professionals over there know the how-to's of this, but I have no specific name or number for you to call. Maybe you can find something in the phone book, but I don't know how long you have to work with before the branch you have dies. Best wishes on this.

Answer 3

Treat it with a spray on fungicide...I may take a couple of days to kill it(the fungus, not the bush. Go to a hobby and garden shop (not home depot or lowes, etc.) tell them what you have and follow their advice. I've grown roses for 20 years, they are beautiful, but a pain in the butt. You might also try watering them in the morning instead of at night. Where I live, the humidity causes a condition called chlorosis...the leaves turn yellow, then get brown spots and fall off. The bush doesn't die, but look like it. I had the fungus looking stuff, I was told it was mite infestation, so off I went to gey an insecticide also.
Good luck sister.

Answer 4

Yup. Sounds like powdery mildew. Get a fungicide from your local nursery. Also pick off the infected leaves.

Answer 5

Bobby is correct. It sounds like a type of Fungus and it will continue to kill your Bushes if you do not spray them with a Fungus Killer. You can buy the Concentrate at Walmart and keep them sprayed. If it rains Respray them...Best of Luck

Answer 6

This is a fungal disease. Sphaerotheca species infect roses. It generates a powdery white to gray fungal growth on leaves, stems and buds. The fungus penetrates the cell walls to steal nutrients. It rarely kills but does injure the host plant.
Infection can occur on dry leaves if the air is still and humid. Warm temperatures, poor air circulation, and shady conditions encourage the fungus to grow and spread. The optimum temperature for infection is between 68 - 77 degrees F and relative humidity between 40 to 100% is sufficient for the spores to germinate. Low, diffuse light also seems to favor powdery mildew development. There is a general belief that wetting the rose leaves will cause this or black spot but watering is not a direct cause though splashing soil borne spores onto the branches is not a good idea. Clean up all fallen leaves and dust the area with corn meal at 2 pounds of cornmeal into the soil for every 100 square feet. Water well to activate the fungus killing properties. There is a cheap, nonfood grade available at garden centers.

Powdery mildew thrives where high rates of nitrogen have been used promoting tender leaf formation. Organic fertilizers or slow-release lawn fertilizers are good choices.
Sulfur is effective against powdery mildew when used every 7 to 14 days. Garlic naturally contains high levels of sulfur and can be used to make a homemade spray.
To make garlic tea, liquefy 3-4 bulbs of garlic in a blender 1/2 to 2/3 full of water. Strain the solids and add enough water to the garlic juice to make 1 gallon of concentrate. Use 1/4 cup of concentrate per gallon of spray. Add 2 T of blackstrap molasses as a sticker.

Bonide makes 141 sulfur dust, Lilly Miller makes Sulfur Dust, Cooke's is a wettable sulfer, Safer makes Garden Fungicide, & Microthiol Special uses Sulfur.

Do not use sulfur within two weeks of an oil spray.

Soap sprays can dessicate the fungus on the rose.

Cornell oil spray
Mix into one gallon of water, in the order listed:
1 T dishwashing soap (Palmolive, Dr Bonner or Ivory) optional with Sunspray
2 T of ultrafine horticultural oil ( Sunspray brand contains a sticker so no soap is necessary)
4 tsp of baking soda
1 T of fish oil/seaweed emulsion
3-5 drops of Superthrive (plant vitamins)
Spray leaf surfaces LIGHTLY, not to dripping. Reapply every two weeks.

Cornmeal Juice
Make by soaking horticultural cornmeal in water at one cup per gallon of water. Put the cornmeal a nylon stocking bag to hold in the larger particles. Soak over night. Spray without further diluting just pour through a coffee filter to use.

Another really good method is milk spray ...... In 1999, a Brazilian scientist found that milk helped control powdery mildew on cucumbers just as effectively as a synthetic fungicide. So far, there has been success reported on the use of milk to control powdery mildew and black spot on roses.
Any type of milk can be used from full milk to skim to powder. However, the low fat milks produce less odour. The recipe calls for milk to be mixed with water at a ratio of 1 part milk to 7 parts water and applied every 5-7 days for 3 applications.

Potassium bicarbonate Fungicide
Mix 4 teaspoons (about 1 rounded tablespoon) of potassium bicarbonate into one gallon of water. Spray lightly on foliage of plants afflicted with black spot, powdery mildew, brown patch and other fungal diseases. Potassium bicarbonate is a good substitute for baking soda in Cornell spray. There are commercial EPA registered as well as generic products available.

It is best to alternate fungicidal treatments because fungi, like all quickly reproducing organisms, select for resistance to whatever is used against it rapidly leading to non-kill. For the same reason never use a fungicide pesticide all in one like bayer unless you also have insect problems. You will only be harming beneficials & building general resistance for no purpose.
Site specific/ local systemic fungicides of low human toxicity; Immunox & for severe mildew cases use Rubigan.
Slightly more toxic is Benzimidazole; Benlate, Topsin-M, Nova, Strike & Cleary's 3336. toxicity class II- it works against rust and powdery mildew for about 28 days, but its overuse can cause short bloom stems.
Never use a fungicide on unwatered plants. WATER AT LEAST 24 HOURS IN ADVANCE (AND 24 HOURS AFTER IF VERY HOT) OR YOU WILL HAVE BURN PROBLEMS!!