Roses

Few gardeners escape the urge to grow roses. It may strike early or late, but at some point, most of us find their color, fragrance and form irresistible.

There is a rose for whatever your taste or landscape needs – long-stemmed, perfectly formed velvety red blooms; billowy shrubs, covered in soft multipetaled cups of pink; borders of yellow blends; or graceful climbers with fragrant, white blooms. The rose-planting season has arrived, and garden centers are stocking up on the various classes of old garden roses and more recent hybrids.

The American Rose Society classifies antique, or old garden, roses as those that predate the 1867 introduction of the first hybrid tea, “la France.” Old rose experts and enthusiasts, however, don’t always limit themselves to the 1867 date and sometimes include late-19th- and early-20th-century roses that show characteristics typical of old roses, which are low-maintenance plants with fragrant, old-fashioned blooms in subtle colors.

By the mid-1800s, roses were divided into more than a dozen classes, including Bourbon, China, damask, gallica, Noisette and tea roses.

Some old roses, known as species roses, are native to this country, but most antique roses belong to a family tree that has roots in Europe and the Orient. Species roses (and related hybrids) generally are low-maintenance spring bloomers that are good companions in perennial and/or wildflower plantings.

China and tea roses are also recommended for the Houston area. Early Chinas and teas were introduced into Europe in the late 1700s and crossed with the once blooming European classes (gallicas, musks, centifolias and damasks). The results were the Noisettes, Bourbons, Portlands, hybrid perpetuals, polyanthas and hybrid musks.

Because of their profusion of flowers and resistance to disease, the long-lived Chinas are suitable as hedges-or as specimens. 'Mutabilis,' a China that's dated prior to 1894, is outstanding in Houston gardens, and recently gardeners have reported shrubs 15 or more feet in height and covered in single, yellow-orange-crimson blooms.

The teas, which flower heavily in spring, and fall and some in summer, have large, fragrant blooms in crimsons, pinks, yellows and white. Theses old roses are better than other old roses for cutting, and they are generally resistant to black spot. The fragrant, pink cupped “Duchesse de Brabant” (1857) was Teddy Roosevelt’s favorite.

Another Houston-area favorite, 'Souvenir de la Malmaison" (1843), is a Bourbon with large, pale pink flowers and is named in honor of Empress Josephine, whose vast collection of roses grew at her country estate, Malmaison.

Modern roses are bred for beautiful blooms in many solid colors and blends. They include fragrance and disease-resistance varies. See the accompanying story that lists many Houston Rose Society favorites.

Modern roses are classified as:

• Hybrid teas - long, pointed buds Dome one to a stem; formal, upright growth to 6 feet.
• Floribundas - continuous clusters of blooms on bushy, 2-to6-foot shrubs.
• Grandifloras - tall, slender shrubs with hybrid tea and floribunda characteristics; 5-6 feet.
• Polyanthas -clusters of smaller flowers on lower-growing shrubs.
• Miniatures - small, bushy shrubs often kept under 2 feet with small semidouble or double flowers that, unlike many modem roses, grow on their own roots.
• Climbers - some flowers bloom in the spring and others are ever-blooming; 8-to-20-foot canes.

Planting Roses

Roses need at least five to six hours of daily sun. While roses complement other plants, avoid planting too close to other shrubs and trees.

Roses like slightly acidic soil – a Ph of 6.5 is ideal – and good drainage is essential. A soil rich in organic matter will help provide nutrients as well as ensure drainage. Amend gumbolike soil with compost. Many rosarians add smaller amounts of alfalfa pellets, fish meal, cottonseed meal and/or bone meal to enrich growing conditions.

Raised beds are best. Add a rose or two to raised existing beds or create beds for roses only. The Houston Rose Society recommends a bed 3 feet wide to accommodate a single row of roses and a bed 5 feet wide for two rows. Space beds 4 to 5 feet apart to allow easy access to the plants in both.

If you're energetic, clear the area of turf and weeds where you wish to build a rose bed. Or simply place eight or so sheets of newspaper within the bed area to kill grass and weeds.

Build a raised bed 8-12 inches high with landscape timbers, bricks or stones, and fill with equal parts soil, sand and organic matter. Mix well. Or fill the bed with a good rose mix from a soil yard or a bagged rose mix from a nursery. It's best to wait a couple of weeks before planting to allow the soil to settle.

Bare-root roses can be planted now to mid-March. Potted roses can be planted almost anytime, but it's best to plant before the long, hot summer.

To plant a bare-root rose, soak the roots several hours in water. Cut away broken roots, and prune the canes back to a foot, to an outside growth eye. Dig a hole at least 18 inches wide and a foot deep. Add a handful of bone meal or super phosphate. Cover this by creating a mound of soil in the bottom of the hole. Place the rose on the mound so that the bud union (the enlarged, knoblike part of the plant above the roots) is 2 inches above ground. Carefully arrange the roots around the mound. Fill the hole two-thirds full with the soil mixture, firming to remove air pockets. Fill the remaining space with water; allow to drain. Fill again; drain. Fill the rest of the hole with soil mixture.

To plant a potted rose, dig a hole slightly deeper than you wish to plant the rose and slightly wider than the pot. Work the soil in the bottom of the hole and add a handful of bone meal or superphosphate. Cover this with soil until the hole depth is equal to the depth of sod in the pot. Cut the bottom out of the pot; position the rose in the hole so that the bud union is about 2 inches above ground level. Slit the sides of the pot and remove the rose gently, trying not to disturb the roots.

Fill the hole with water to force out trapped air. Refill after water soaks in; allow to drain. Then fill the hole with soil mixture. Tamp gently with your hands.

Fertilizing and Watering

Begin a fertilizer program with new growth in the spring. Then fertilize monthly or lightly every two weeks until September. Avoid over fertilizing, and water before and after applying any fertilizer. Composted manure, compost and other organic supplements are beneficial. There are also numerous commercial rose fertilizers available.

Roses need at least an inch of water a week - more in dry heat. Water slowly and deeply. Container roses will need attention during the summer.

Pruning Roses

On Valentine's Day we give roses-and prune roses. Roses benefit from pruning before they break dormancy. Pruning removes weak wood that drains the plant, decreases the chances of disease, and promotes Study each rose to determine

Pruning needs. Leather garden gloves and clean, sharp clippers will make the job easier.

Modern and antique roses vary in their pruning needs. Antiques grow on their own rootstock and do not require heavy pruning, just a light shaping.

If an old rose is a once-a-year bloomer, wait until it flowers to prune. Remove any dead or diseased canes and twiggy growth. Then give the overall plant a light trim. Repeat bloomers can be lightly trimmed on Valentine's Day. During the growing season, occasional light trims may be in order after a flowering spree to shape a vigorous repeat bloomer.

Modern roses need more. Prune the bush back by about a third of its height. Make 45-degree cuts a quarter-inch above a growth or bud eye on the outside of the cane. A growth or bud eye is a small bulge with a small "eye" and a horizontal crease below it. When the plant breaks dormancy, the eye will become a new shoot.

Cutting to outside bud eyes encourages outward growth rather than growth toward the center of the plant, which would decrease* air circulation and, therefore, plant health. Cutting at 45-degree angles prevents moisture from accumulating on the tips, again discouraging disease. Prune modern roses to get rid of nonproductive, damaged and unwanted canes. Look for canes that are brittle, brown or black Remove this old or dead wood at the bud union. Remove spindly stems smaller than a pencil.

Prune any canes that emerge below the bud union that bump at the base of the plant where a preferred rose has been grafted onto hardy rootstock. These are rootstock suckers, and they may bloom, but the flowers will differ from those produced above the graft, and these suckers sap energy from the desired, productive canes that grow from the bud union.

Leave three or four healthy canes for an open, vase-shaped effect. This gives the rose breathing room, opening the center for better air circulation, which in turn helps discourage fungal diseases such as black spot. Sunlight better penetrates an open rose.

Climbers are pruned according to their bloom time. Those that flower once a year are pruned after they bloom. Repeat-bloom climbers are generally pruned while dormant, so prune these when pruning modern hybrid teas. Prune all but three or four healthy young canes. Remove unproductive canes, dead or diseased canes, old and weak canes. If the rose is grafted, remove any rootstock suckers.

Climbers flower best when the canes are encouraged to grow more horizontally or arched rather than straight up. Climbers that grow straight up tend to flower only on the tips of the canes. Canes trained horizontally or arched will more likely flower at each leaf axil.

Miniature roses grow on their own root systems. Remove the top growth so that the plant is no more than a foot tall. Some gardeners prune to 6 to 8 inches. Remove twiggy growth and open the center of the plant. Take out 2-to3-year-old canes. The best flowers come on new growth.

Nip Pest Problems in the Bud

Aphids, thrips, black spot and powdery mildew are four enemies of the rose. Aphids suck sap; thrips bruise blooms.

Eliminate the soft, pear-shaped aphids (often on the undersides of the leaves ) with insecticidal sap applied according to package instructions.

Thrips attack buds, burrowing down into unfurled petals. They like a dry environment, so keep your roses watered. Spray with insecticidal soap.

Our warm, humid climate triggers black spot, a fungus that attacks rose foliage and can weaken the bush if not stopped with a fungicide. Do not water foliage while plant is infested. Modern roses tend to be more vulnerable to black spot than old roses, and many require regular fungicide treatment. But there are some among the modern varieties that hold their own fairly well against the disease.

Powdery mildew is a fungus that appears in early spring or late fall when nights are cool and days are warm. New foliage with the whitish mold should be sprayed with a fungicide.