Radiant Roses

by Tina Mast // April - May - June 2018

The rose is known as a lovely addition to the garden. It’s also known to be high maintenance. The secret of success is to give it regular attention and provide it with the most optimal growing conditions that you can. Here are some guidelines for planting, growing, and maintaining radiant roses.

LOCATION AND SPACING: Plant roses in full sun where they will receive at least six hours of light a day. Most bush-types should be spaced at least three to four feet apart, and space climbers six to 10 feet apart.

PLANTING: If your soil is very poorly drained, plant roses higher than the ground surface on a mound to facilitate better drainage. Make sure plants are well-watered before planting.

Dig a wide hole about three times the size of the rootball. The hole should be about the depth of it. Rough up the sides of the hole so there are no slick surfaces. Toss the dirt into a large container or wheelbarrow. Create a mix of 50% native soil, 40% pine bark soil conditioner, and 10% organic material (or more for sandy soils) such as composted manure in your container or wheelbarrow.

Carefully remove the plant from the container and set it in the hole making sure the top one-eighth of the rootball is above the grade of the surrounding soil if you have clay, and at the grade if you have sandy soil. If the roots are compacted and tangled, gently loosen them by hand. Backfill the hole with the soil mix and build up soil in a mound up to the level of the rootball. Make sure that the soil is one to two inches below the bud graft union (the knotty, burled part from which the shoots are coming). This will help prevent suckers coming from below the graft. Create a three-inch lip of soil around the edge of the planting hole to catch water. Water thoroughly with a diluted solution of Fertilome Root Stimulator.

MULCHING: Mulching conserves water, insulates plant roots from temperature extremes, and reduces weeds and the spread of soil-borne disease. I recommend a two-inch layer of mulch.

WATERING AND FERTILIZING: Water deeply and soak the root area once or twice a week, preferably in the morning, if there has been less than one inch of rain. Avoid getting water on foliage as it can promote disease. The amount needed will vary based on weather conditions, natural rainfall, plant size, soil structure, and sun duration/intensity. Use a fertilizer formulated for roses and feed according to label instructions. Generally, roses should be fed monthly during the growing season, usually April to mid-August. A couple shovelfuls of compost spread under each rose’s mulch layer at the beginning of the season will promote beneficial soil organisms as well as feed the plant.

SPRAYING: Roses are prone to a number of diseases and pests. A healthy, well-cared for plant is better able to resist attack than a neglected one. Keep roses well fed and watered, and regularly remove dead wood, fallen leaves, and spent blooms. During the dormant season, right after annual pruning, spray with dormant season horticultural oil to destroy many disease organisms as well as overwintering insect eggs. To control disease and insects on many hybrid roses, a regular spraying regimen during the growing season will most likely be required. The best time to spray is in the early morning before the sun hits the plants. 

PRUNING: Pruning extends the life of your roses, improves flower quality, regulates size and shape, and reduces disease. It is a good idea to have a bucket of 10% bleach solution to dip your pruners in between cuts in order to prevent the spread of disease. Bypass-type pruners and loppers are recommended for hand pruning.

For annual pruning, prune in spring just as the buds begin to swell prior to the unfolding of vegetative growth, usually late February or early March. Remove all shoots growing out from under the knotty, burled bud graft union at the base of the plant and dead, damaged, or diseased wood. Gently flake off old bark from the graft union to help promote new shoots. Remove all inward-growing branches and any that are pencil-sized or smaller to form a neat, open-centered plant. Remove canes that are four years or older, leaving about three to five canes of about one-half inch in diameter for hybrid teas, and five to seven canes for floribundas and grandifloras. On the remaining canes, reduce them down to leave at least three to five outward-facing buds on each cane. Make all cuts at an angle about one-quarter inch above an outward-facing growth bud.

On climbing roses, don’t prune for the first two to three years, except to remove dead, diseased, damaged, or crossing canes and any suckers. After two to three years, remove older gray and weak canes, leaving at least three to five vigorous ones. On once-blooming types, prune after their spring bloom. Prune climbers every few years. “Knock Out” roses can be pruned in late winter or early spring. Remove any dead wood and cut large canes down to about 24-30 inches tall (or two inches lower than the desired height of the shrub) making a slanted cut (away from the bud) about one-quarter inch above an outward-facing bud. Remove any diseased and/or spindly growth in the center of the plant.

For seasonal pruning, roses should be “deadheaded” regularly. Prune away old blooms once they are spent. The cut should be one-quarter inch above an outward facing set of leaves that contains five or seven leaflets. Control cane height by choosing any set of five or seven leaves along the stem to make the cut. In general, don’t remove more than one-third of the plant during the growing season. 

Tina Mast

Communications director at Homewood Nursery in Raleigh.