Not mentioned specifically above, but hidden in the comment from MichaelG about Cindi's friend George: I do know George and he gardens in southeastern most Texas. Mid day works for him. What y'all may not know about that part of the Gulf Coast is that in the morning, summer (all eight months of it), the humidity when you wake up is often 100%. It stays 100% until 9 or 10 in the morning. Were he to spray then, the spray on the leaves wouldn't dry and when the sun hit it, it would be more likely to burn where there were droplets. But by waiting till noon, the humidity drops, the temperature rises, and the spray dries fast on the leaves. And that's what you want. Leaving the leaves wet in some some temperature ranges is a way to encourage Black Spot.

Also depends on which fungicide is being used. You need to be careful about spraying Daconil with the sun out when temps get up around 78 F. Daconil is a good cool weather springtime spray here -- helps prevent botrytis. It is not as good as summer heats up as it will burn roses in warm weather. If you spray any fungicide in the evening, spray at a time that your spray dries before nightfall. If the spray does not dry it will likely exasperate the fungal problems. Fungicides are ineffective when wet, and spray on the roses that does not dry within a reasonably short time will contribute to fungal problems.

Like Nancy said, if I never sprayed when the weather was too hot, my roses would go un-sprayed at least half the year. Whether Banner Max, Ortho triforine, or Bayer tebuconozole (sp?), I've never had a burn problem from anti-fungal sprays. I HAVE burned roses with chemical fertilizers a number of times. Ouch! I always try to make sure the plants are well-watered before spraying, but honestly, I don't count out 6 hours. Sometimes I spray an hour after watering. And I've sprayed morning, mid-day, or early evening, just depending on my hectic schedule. It certainly dries fast at mid-day, but if that's preventing a needed absorption period, I can't tell, because I still haven't had any blackspot in ages--ever since I started spraying some of the time with Bayer Advanced Disease Control. That stuff is a miracle product! (I do alternate it with Banner Max, since I already have a good supply of the Banner Max). Might as well keep the fungal spores off-balance. Mike

You're welcome. From what I see about the label on line: VEGETABLES, HERBS, SPICES, ROSES, HOUSEPLANTS, FLOWERS, TREES, AND SHRUBS. APPLICATION INSTRUCTIONS ferti-lomeî ROSE, FLOWER & VEGETABLE SPRAY is an effective fungicide for the prevention and control of various Fungal Diseases including Powdery Mildew, Black Spot, Downy Mildew, Anthracnose, Rust, Leaf Spot, Botrytis, Needle Rust, Scab and Flower, Twig and Tip Blight, and Alternaria. As a preventative, apply ferti-lomeî ROSE, FLOWER & VEGETABLE SPRAY on a 7 to 14 day schedule until the potential for Disease development is no longer present. To control Disease already present, apply ferti-lomeî ROSE, FLOWER & VEGETABLE SPRAY on a 7 day schedule until Disease pressure is eliminated. Then continue spraying on a 14 day schedule to prevent the Disease from reoccurring. To prevent Rust Leaf Spot Diseases, Anthracnose and Scab, begin applications at the first sign of Spring budding. To prevent Powdery Mildew, apply in mid-Summer or when Disease is first detected. Continue applications until Disease pressure no longer exists. MIXING INSTRUCTIONS Mix ferti-lomeî ROSE, FLOWER & VEGETABLE SPRAY at the rate of 2 tablespoons (1 fluid ounce) per gallon of water. Thoroughly mix solution and spray all Plant surfaces (including undersides of leaves) until completely wet. Frequently mix solution as you spray. Hopefully, you didn't exceed the 2 TBS per gallon. Even at that rate, if your weather is expected to be as hot as you've indicated, you might experience some burn. But, what is worse? Scorched leaves of black spotted, falling foliage? You're right, it's always something! Your higher heat is going to help prevent some of the disease spread because it can get too hot for the spores to germinate. Until it begins remaining cooler, I wouldn't spray be once every two weeks for fear of burn. Good luck! Kim