Successful Roses in Iowa depends on season long care and proper winter protection.
Planting Roses
Planting is the first and most important step in assuring winter survival. The graft is the most tender portion of the rose plant therefore the planting hole should be deep enough so the graft is 2-4 inches below the surface.
Pruning Bare Root Roses
- Remove dead wood.
- Cutback cane tips.
- Prune roots lightly.
Rose Planting
- Place the rose in the newly dug hole.
- Back fill the soil making sure the rose is at its proper depth.
- Water and allow the soil to settle naturally. (do not compact the soil)
Rose Fertilization
- Apply an even analysis fertilizer @ 1 lb. actual nitrogen per 1000 sq. ft.
- Apply fertilizer once in May and once in July.
- Weigh the fertilizer accurately.
- Distribute the fertilizer evenly over the entire rose bed.
Proper Pest Control Methods
When applying or treating roses for pests:
- Read and follow label directions.
- Wear protective clothing.
- Measure pesticide accurately.
- Keep equipment clean and in good operating condition.
- Post signs in treated areas.
- Keep accurate records.
Rose Pest Control
- The most common diseases in roses are Black Spot and Powdery Mildew.
- Begin the spray program May 15.
- Spray roses at recommended rates every 7 to 10 days.
- Alternate between two different pesticides for decease control.
Rose Insect Control
- Scout weekly for insect problems.
- Use mechanical methods of control when possible.
- Use insecticides at recommended rates only when necessary.
- The most common insects in roses are Spittle Bugs, Aphids, and Spider Mites.
Deadheading Roses
Deadheading (removing spent blossoms) allows a constant bloom throughout the season. Methods vary with growth habits of the rose variety.
Tea Roses
Cut back spent flowers to the to the first leaf with 3 leaflets.
Grandiflora & Floribunda Roses
- Remove individual flowers as the petals drop.
- Remove entire flower head back to the first leaf with 3 leaflets when all of the blossoms are spent.
Hardening Off Roses for Winter
- Discontinue the spray program Sept. 15. (slight disease infestations slow plant growth)
- Discontinue dead-heading roses Oct.1. (seed development slows plant growth)
Steps
- Remove all wood mulch and tie up the roses using twine in late October. (Do not trim the roses back)
- Mound the roses with 10-12 inches of soil no earlier than November 15th.
- Build an 18-24 inch high fence using re-rod and chicken wire.
- Loosely place oat straw around the roses in the fenced bed.
- The following spring:
- Remove the straw mulch.
- Remove the soil mounds.
- Remove the fencing.
- Cut back the roses to 8-12 inches.
- Mulch the rose bed with 3-6 inches of bark mulch.