Growing roses in northern Illinois means choosing roses hardy to USDA Planting Zones 4b and 5a, depending on your exact geographical location. Because the northern Illinois region can experience winter low temperatures as low as -25 degrees Fahrenheit, roses must be able to withstand the cold. Paul's Scarlet climbing roses are hardy to USDA Zones 5 through 9. Because Paul's Scarlet climbers are hardy only to Zone 5 and northern Illinois is borderline for this zone, you must give these climbers a little extra winter protection to ensure they survive.
Position a strong climbing structure for the climbing rose. Use a sturdy archway or arbor, or attach a trellis to a wall.
Prepare the soil area. Dig an 18 inch wide and 12 inch deep hole for the plant. Mix compost with the soil you removed for the hole, adding 1 part compost to the soil to make the soil-to-compost ratio equal.
Soak a bare root rose bush in cool water for up to 24 hours before planting.
Place the bare root bush into the prepared hole so the bud union will be between 1 and 2 inches below soil level. Place a container rose in the hole so the rose will be at the same depth as it was in the container. Back-fill the hole carefully with the soil and compost mixture.
Water the Paul's Scarlet climber regularly throughout the growing season. Provide about 1 inch of water every week if there is insufficient rain. Keep irrigation water off the rose foliage to avoid disease.
Mulch around the base of the shrub with about 3 inches of shredded leaves or wood chips. This conserves soil moisture and slow weed growth.
Fertilise the climbing roses for the first time in the growing season when new growth is 6 inches long. Apply 1 tbsp of granular fertiliser onto the soil, and work it in with a hand rake. Apply a second dose of fertiliser later in the season, only if you notice yellow or greyish leaves.
Leave the climbing rose to grow without stringent training during the first growing season. Use stretchy ties to secure the longest canes to the climbing support, positioning the ties every 15 inches along the horizontal cane. Keep at least 4 inches of loose space between the canes and the structure for adequate ventilation.
Wait until the first hard freeze, and untie the canes from the structure. Lay the canes flat on the ground, and cover the canes and the base of the plant with about 12 inches of shredded mulch. The mulch protects the roots, the bud union and the canes from winter damage.
Remove the mulch after the final frost of the spring, and tie the canes back onto the support structure.
Prune Paul's Scarlet climbing rose after it blossoms only, or you may remove future flowers. Cut away the old and weak canes with the pruning shears, and leave about five vigorous canes growing. Prune lateral branches growing off the main canes by cutting them back so only five sets of leaves remain on each lateral.
Train the climber by gently tying the canes to the structure in a horizontal configuration, and allow the laterals to grow vertically from the canes.
Another option for winter protection is to leave the canes on the structure and construct a burlap cover for them. Wrap the canes with burlap, stuffing straw inside the burlap for extra insulation. Tie the burlap gently to the structure with twine.