I have noticed black spot on some of my roses. What do you suggest?
Try 1 cup of cornmeal to 1 quart of water. Set for one hour and spray roses.
In rose care the best thing is a systemic feed that also has properties against black spot. After care, the best thing is a commercially produced and carefully applied fungicide labelled specifically for black spot.
Once you get rid of the black spot, be careful to avoid reintroducing conditions favourable to its development-don't water close to or after dark; keep the center of the plant open with proper pruning; space new bushes proper distances apart; and disinfect your pruning tools between cuts, not just plants.
Feed with one of the systemics to keep a beautiful and healthy plant.
If you have rose bushes, fungal diseases such as black spot and mildew can be prevented, but not cured. Spray a fungicide every 7 to 10 days as a preventative measure.
By Terri H.
Listerine works great for this...buy the generic for more frugal solution..get original flavor.
I have also heard it is very important to remove any leaves from beneath the rosebushes, that may have fallen in autumn etc, to stop the fungus from going through the bushes that way.
Diamondee, Do you use full strength "listerine" or do you dilute it?
I have also heard that tea tree oil works well for fungus on plants. I'm not sure about the quantities, but dilute maybe twenty drops per gallon of water, put in a spray bottle, shake well, and spray away. Doing the same with citronella oil also works for many plant pests. A combo of the two oils might be a good overall cure and even preventive measure (spraying once a week in warm months) for problem plants, both indoors and out. Diluted garlic oil is also a good bet for pests of various sorts, but can burn the leaves of plants. Crush several cloves and let them soak overnight in a cup of light vegetable oil (Olive is too heavy), then strain out the garlic bits with cheese cloth and mix the leftover oil with water.
HAPPY SPRING FROM MISSOURI
What can be done about roses that have extreme black leaf?
By Paula H.
In the old days, they would tell you " throw your dirty dish water on it". Now a days very few people wash dishes by hand. So put a little dish soap in your watering can, suds it up and pour it over your rose bush. I would remove the bad leafs. I have alot of rose bushes and it works for me. Do not use eletric dishwashing detegent!
I was having problems growing roses, so I went to a class. the most important thing I learned was to make sure I never water the leaves. Since I started only hand watering the rose bushes from the bottom, they are doing great! I also keep lots of composted soil around them, covered with mulch and then I do not even need to fertilize them at all.