On individual disturbed or undisturbed Macartney rose clumps.
- Undisturbed – Undisturbed plants that are 5 feet or less in height and diameter.
- Disturbed – Mowed or otherwise disturbed plants should be treated within 3 years of disturbance. However, avoid spraying them earlier than 9 to 12 months after mowing or when the plants have a high percentage of new growth. Expect poor control if plants are less than 3 feet tall when sprayed.
When to Apply:
Begin in the spring under good growing conditions when the soil temperature reaches 75 degress F at 12 to 18 inches deep. Stop in late spring during flowering and hip (“apple” or fruit) formation. Begin again in late summer or early fall under good growing conditions, and continue until soil temperature drop below 75 degrees F.
1. Prepare Equipment
Small pump-up garden sprayers, backpack sprays, cattle sprayers, or sprayers mounted on 4-wheel all-terrain vehicles (ATV) work well. For a few plants, garden sprayers are best; in denser stands, backpack sprayers are usually the most efficient; and in large acreages or as the distance between plants increases, ATV sprayers become more efficient.
Larger plants require higher sprayer pressures. Make sure your sprayer has an adjustable nozzle that can deliver a coarse spray (large droplets) to the top of a 5-foot clump. Conejet™ 550 x-6 or x-8 adjustable cone nozzles work well.
2. Mix Herbicide Spray
You can achieve 76 to 100 percent rootkill by spraying Macartney rose with Grazon P+D™, which is a restricted use pesticide. A certified Texas Department of Agriculture (TDA) Pesticide Applicators License is required to buy or apply the product.
To prepare the spray mix, add Grazon P+D™ at a concentration of 1 percent to water. To make sure that spray sticks to the waxy foliage, add either liquid dishwashing detergent or a commercial surfactant to the spray mix (see tables below). It may be helpful to add a dye, such as Hi-Light™ Blue Dye, to mark the plants that have been sprayed.
Recommended spray mixture using a surfactant or liquid dishwashing detergent.*.
|Ingredient||Concentration in spray solution||Gallons Mixed|
|3 gal.||14 gal.||25 gal.|
|Grazon P+D™||1%||4 oz.||18 oz.||1 qt.|
|Surfactant||1/4%||1 oz.||3 oz.||8 oz.|
|Hi-Light Blue Dye™||1/4-1/2%||1-2 oz.||3-6 oz.||8-16 oz.|
*All spray solutions are mixed in water.
3. Spray the Macartney Rose
Macartney rose can be sprayed in either the spring or fall under good growing conditions. You should not spray when flowers or fruits are present or when the soil temperature is below 75 degrees. The spray period may last through late October
Wet the entire foliage in the canopy of each Macartney rose plant until the leaves glisten, but not to the point of dripping. The spray pressures may need to be high to penetrate larger plants with heavier canopies (300 psi or higher).
Keep these points in mind:
- Follow herbicide label directions.
- For best results, don’t spray when:
- rains have stimulated new growth.
- leaves are wet.
- plants are less than 3 feet tall after mowing.
- foliage shows damage from hail, insects or disease.
- soil temperatures are below 75 degrees F.
- you are working immediately upwind of desirable trees, shrubs or crops.
- flowers or fruits are present.
- Treat only what can be managed in a year. Control measures may suffer if too much is taken all at once.
- The cost of treatment increases rapidly as the rose hedge becomes larger and more dense. Also, controlling Macartney rose is not a one-time job. You’ll need to go over your land now and then to eliminate unwanted rose hedge sprouts.
- Macartney rose generally grows on soils with a high clay content. Soil-applied herbicides generally should not be used on such soils and are generally ineffective for controlling rose hedge.