Fall Garden Preparation for Knock Out Roses

Pruning

• Most rose pruning takes place in the spring, but gardeners should perform some light fall pruning as well. Remove the last blooms of the season as they die. Also, cut off diseased or dead parts of the plant during the fall. Tall, canelike rose plants often sustain damage from whipping around in winter winds. However, Knock Out roses are somewhat short and bushy, so gardeners should only prune back any extra leggy stems that might blow around excessively.

Soil Adjustments

• Gardeners should not apply fertilizer to roses during the fall, because it stimulates new growth that will easily sustain winter damage. Fall is a good time, however, to adjust the pH of the soil. Get a pH testing kit or send a soil sample to a lab or university for pH testing. Roses grow best in soils with a pH between 6.5 and 6.8. Gardeners with a pH below 6.5 should use a limestone soil additive to raise the soil pH. Gardeners with a pH above 6.8 can add sulfur to lower the pH.

Mulching

• Mulch insulates the soil, protecting rose roots from cold damage. The University of Vermont Extension suggests a plant-based mulch like straw, peat moss, wood chips, bark mulch or evergreen branches. Sometime during the fall, cover the soil around the base of the Knock Out roses with up to a foot of mulch. The Maryland Rose Society recommends slowly removing the mulch a little at a time from the base of the plant during the spring.

Mounding

• Besides applying a layer of insulating mulch around the base of rose plants, many gardeners also create a mound around the base of plants to add extra insulation. Instead of mulching, create a mound of loose soil between 8 inches and 1 foot tall around the base of the plant. The University of Vermont Extension recommends soil mounding instead of mulching for gardeners with mice that might live or burrow in mulch.