When is the best time to apply dormant spray to my roses?Updated 2 months ago
After finishing your dormant pruning, take a moment to clean the rose bed before applying the dormant spray.This is the time to remove all debris and old rose plant material & leaves around the base of your roses. Yes, every little leaf and stem - toss everything into the trash—not the compost bin. Why? Overwintering diseases and pests could be hiding within that plant material, just waiting for the warm weather to thrive. Think of this cleanup as setting the stage for a fresh, healthy growing season.
Once your rose beds are cleared, it's time to kick off your dormant spray routine. Timing is key here—you'll want to apply your spray within a week of dormant pruning and ideally before the buds start to push out. My approach is simple, effective, and organic, bringing great results year after year. Start with two straightforward products: a horticultural oil and a copper spray. Copper, available in liquid form, is my favorite fungicide here on the farm. It's a powerhouse disease control, but be sure to follow the label application rate directions, as too much copper can cause burning to the plant. Follow this up with horticultural oil—it's a fantastic insecticide that works by smothering overwintering insects. Together, these two are an unbeatable team for keeping diseases and pests under control in your rose garden. Make sure to spray on a dry, calm day when temperatures are above 40°F (4°C) but below 85°F (29°C).
For a more comprehensive routine, you can also include a follow-up (non-organic) systemic treatment once you see the first stages of new leaf growth to tackle additional overwintering diseases. Apply a systemic fungicide like propiconazole. It's amazing for preventing black spot, rust, and powdery mildew. Unlike copper, propiconazole is absorbed by the plant, giving you longer-lasting protection. Aim to apply your first and second fungicide treatments a minimum of two weeks apart. If you want to stay all organic you can just apply a second round of liquid copper or lime sulfur instead of the propiconazole. Using this friendly, strategic approach will set your roses up for success, helping them grow strong and stay healthy throughout the season!
Proper application is key to success—check the product label and use the correct application rate, pay attention to the intervals between applications and and avoid spraying while pollinators are out and about. And don't skip protective gear! Always wear proper PPE (personal protective equipment) to ensure you're protecting not only your plants but yourself.
The truth is, most people fail at disease control because they don't follow the directions for the correct application rate or apply the product not as directed on the label. If you want to elevate your gardening skills, consider taking a chemical application safety class through your local agricultural extension or master gardener program. Or grab Felicia's favorite chemical safety book. It's a great way to learn how to read labels, mix products, apply them safely and really master this essential part of rose care. And remember, even organic products are still chemicals that need to be handled with care.