AMES, Iowa — Modern roses, such as hybrid teas, grandifloras and floribundas, are attractive additions to the home landscape. While roses are beautiful, Iowa State University Extension and Outreach horticulturists say they do require good care. Proper planting is critical. After planting, important cultural practices include watering, fertilizing, deadheading, weeding, pest control and winter protection. To have additional questions answered, contact Hortline at 515-294-3108 or firstname.lastname@example.org.
Remove the soil in late March or early April in southern Iowa, mid-April in northern portions of the state. A frost or freeze in early spring won’t harm the roses.
The upper portions of modern roses, such as hybrid teas, floribundas and grandifloras, typically winterkill due to exposure to low winter temperatures and extreme temperature changes. Gardeners should prune out the dead wood after the winter protection is removed from modern roses in late March to mid-April.
In early spring, all dead wood should be removed from hybrid tea and other modern roses. Identifying live and dead wood is easy. Live wood is green and has plump, healthy buds. When pruned, the center of the stem (pith) is white. Dead wood is brown and has no live buds. Its pith is brown or gray.
When pruning roses, make the cuts at least 1 inch below the dead, brown-colored areas on the canes. Make slanting cuts about one-fourth inch above healthy, outward-facing buds in the same direction as the bud. Remove the entire cane if there is no sign of life.
Because of the severe winter weather, hybrid tea, grandiflora and floribunda roses often suffer a great deal of winter damage. Normally, the primary objective of rosarians in the upper midwest is to remove all dead wood and save as much of the live tissue as possible. If roses suffer little winter damage because of a mild winter, prune the rose canes back to within 8 to 12 inches of the ground.
In Iowa, early spring (before the plant begins to leaf out) is the best time to transplant a rose. The optimal time period is normally early to mid-April. Dig up the rose using a shovel or spade and replant immediately. After transplanting, water the rose on a regular basis for several weeks.
Dormant, bare-root roses should be planted in early spring before the plants begin to leaf out.
Before planting bare-root roses, soak their roots in water for several hours. In Iowa, the bud union (denoted by a knob or crook in the stem of the plant) of hybrid tea, grandiflora and floribunda roses should be planted 2 to 4 inches below the soil surface. This helps protect the rose from harsh winter weather. Dig a hole large enough to accommodate the plant’s roots.
Position the bare-root rose in the center of the hole with the bud union at the proper depth. Spread out the plant’s roots then begin to place soil back in the hole. Gently firm the soil around the roots as the hole is filled. Thoroughly water the plant after the hole has been filled. Let the soil settle and mound 3 to 4 inches of soil around the base of the canes to prevent desiccation injury. Remove the soil once growth begins.