Extension Communications
3614 Administrative Services Building
Ames, Iowa 50011-3614
(515) 294-9915
10/26/98
Contacts:
Cindy Haynes, Department of Horticulture, (515) 294-2751
Elaine Edwards, Extension Communication Systems, (515)
294-5168
Yard and Garden Column for the Week Beginning Oct. 30
Winter Protection of Roses
By Cindy Haynes
Extension horticulturist
Iowa State University Extension
We enjoy the blooms and fragrances of many types of roses during the summer. But some varieties of roses are not reliably winter hardy in Iowa. Hybrid tea roses often require protection to ensure winter survival. There are several ways to protect your roses and increase their chances of surviving Iowa's harsh winter weather. These winter survival strategies should begin after two or three hard freezes when the plants are entering dormancy. This normally occurs in late October to early November in northern Iowa. In central and southern Iowa, rose protection should begin in early to mid-November.
The first protection strategy employs rose cones. These cone-shaped, insulated, foam products dot many Iowa landscapes in the winter. But rose cones alone do not provide adequate winter protection. After the roses are cut back to fit under the cones, mound 6-10 inches of soil around each rose plant. The rose cone is then placed over the rose with the mounded soil. The cone should cover the rose completely. Another layer of soil should then be placed around the outside base of the rose cone. A weight, like a brick or cinder block, is then placed on top of the rose cone. This last soil layer and the weight will help ensure that the cone does not blow off during strong winter winds. Rose cones can quickly become tumbleweeds if not secured properly.
While rose cones are easy and convenient, other protective methods are often more successful. Instead of cutting back your rose plants to fit under a rose cone, simply tie the branches together and mound approximately 1 foot of soil around the base or crown of each plant. Any existing mulch should be removed prior to the addition of soil. Finally, add a couple of feet of clean, weed-free straw to the top of the mounded soil. A 2- to 3-foot tall chicken wire fence encircling each rose or the entire rose garden will help hold the straw in place. In early spring as the soil begins to thaw, gradually remove the layers of straw and soil. At this time the rose branches can be cut back and the dead tips removed.
Tree-form or rose standards also require winter protection. Half to two thirds of the root system should be dug. Dig a shallow trench on the opposite side and carefully bend the tree rose down to the trench. Be sure not to damage any of the branches. The tree is then buried completely by covering with 8 to 12 inches of soil. A 2- to 3-inch layer of mulch can be added on top of the soil layer. The mulch and soil layer can be removed gradually in early spring as the ground thaws. The tree can be lifted upright after the last frost, making sure to cover any exposed roots.
There are a couple of options in protecting miniature roses. Miniature roses can be dug and placed in containers for enjoyment indoors in the winter. They should be planted in a suitable container and brought inside before the first hard frost. Miniature roses will continue to bloom if placed in a warm, sunny window. To overwinter miniature roses outdoors, gently mound 8 to 12 inches of soil over the entire rose plant. A 2- to 3-inch layer of mulch can be added on top of the soil layer. The soil and mulch can be removed in early spring as the ground thaws.
Climbing roses that bloom on last year's wood also need winter protection. Roses should be carefully removed from their trellis, arbor or climbing structure and gently placed on the ground in a shallow trench. The branches are then buried completely with 8 to 12 inches of soil. A 2- or 3-inch layer of mulch can then be added on top of the soil. The branches can be cut back slightly to a more manageable size but be sure to leave plenty of branches for next year's blooms.
These winter protection strategies should help ensure the survival of your roses. Other hassle-free options include purchasing new hybrid tea roses every spring or planting hardy rose varieties.
ml: isugarden
Extension programs are available to all without regard to race, color, national origin, religion, sex, age, or disability.