Many gardens include at least one rose and perhaps several. Roses are dormant from late winter to early spring (when buds begin to swell), so now is the time for major pruning.

This column presents an overview of the categories of garden roses and brief sections on maintenance, annual pruning and propagation.

Categories of garden roses

The genus Rosa includes up to 180 species, divided into four subgenera. Three subgenera include one or two species, while the subgenus Rosa contains all the other roses, divided into eleven sections. For most gardeners, the most significant section of the subgenus rose is Chinensis, which contributes much to the parentage of today’s hybrid roses. For more info, visit en.wikipedia.org/wiki/rose.

Garden roses are categorized in different ways without reference to botanical principles. In terms of size and shape, the categories are bush (2-7 feet tall), miniature (15 inches tall) and shrub (growing larger than bush roses).

Regarding ancestry, we have three groups: wild, old and modern garden. The wild roses include natural species and their hybrids. The old garden roses originate in the Mediterranean region and include several one-blooming woody shrubs, sometimes called heritage or historic roses. The modern garden roses category began with the 1867 introduction of Rosa ‘La France’ and now includes many cultivars in several categories. For more info, visit wikipedia.org/wiki/Garden_roses.

This column’s image gallery includes rose blossoms from my garden. These archival images were taken during the bloom season and depict the wild, old and modern garden categories.

Maintenance pruning

Throughout the growing season, maintenance pruning includes deadheading spent blossoms. For modern garden roses, deadheading involves removing the bloom stem to the first or second five-leaf set (sometimes called a “true leaf”).

For old garden roses, trim the spent clusters rather than cut down to the “true leaf.” The secondary clusters will still be blooming after the primary cluster has finished.

Maintenance also includes cutting off diseased or damaged wood and, for grafted roses, removing shoots (suckers) that emerge from below the graft union.

Good pruning practice includes using sharp, clean pruning shears, loppers or saws, as required by the thickness of the canes. Make cuts at a 45-degree angle, 1/4 inch above an outward-facing bud.

Annual pruning

Annual pruning is essential for maintaining plant health, encouraging vigorous growth and ensuring prolific blooms. This process also provides the opportunity to adjust the size and form of the plant to meet landscaping priorities.

Hybrid tea roses are popular in many types and cultivars. Substantial pruning encourages larger (but fewer) blooms. Cut back aggressively: reduce the plant to 12-24 inches high. If you prefer more (but smaller) blooms, prune less aggressively and leave the plant taller. Retain three to five of the thickest, healthiest canes, and remove the weaker, spindly ones. To shape the plant, create an open-centered, vase-like form to allow air and light into the plant’s center.

A radically different approach to pruning hybrid tea roses is shearing the plant to about 18 inches in height. This is done by lopping the canes straight across the top, using hedge shears or other tools. Research done several years ago by England’s Royal Horticultural Society concluded that this approach “produces better rose bushes than the classical method” in terms of bloom, growth, health and overall performance.

Climbing roses have long, arching canes that bloom on either old or new wood, depending on the variety. Avoid cutting back main canes that are healthy and undamaged. Delay annual pruning until the plant has been established for two or three years. Secure the main canes horizontally to encourage lateral shoots that bear flowers. If your climber blooms on old wood, prune immediately after flowering. Every two to three years, remove the oldest canes at the base to encourage new growth. Cut lateral flowering shoots back to two or three above the main canes in late winter or early spring.Rambling roses are vigorous growers that produce masses of small flowers, often in large clusters and typically bloom once per season. They can quickly become unruly; regular maintenance after flowering keeps them in check. Allow young ramblers to grow freely for the first couple of years to establish. Pruning controls size, promotes healthy flowering, and removes old, unproductive canes to encourage new canes. Since ramblers bloom on old wood, prune immediately after their summer bloom. Cut out about one-third of the oldest canes at the base to rejuvenate the plant. Secure new canes horizontally to encourage flowering along their length. Remove overcrowded or tangled canes to keep the plant manageable.

Wild roses, called species roses, often have simple, single blooms and a more natural growth habit. California natives like Rosa californica are valued for their hardiness and ecological benefits. These roses are essential for wildlife (providing hips for birds and shelter for insects), so consider leaving some hips intact for ecological benefits. Pruning objectives include maintaining the plant’s natural form while promoting health and controlling size. Minimal pruning is required. Focus on removing dead, damaged or diseased wood. If controlling size, trim lightly after flowering but avoid heavy cuts that disrupt the natural shape. Every few years, remove one-third of the oldest canes at the base to rejuvenate growth. Species roses often spread via underground runners. Allow suckers to grow for a natural thicket effect or remove them to contain spread.

Propagating roses

Propagating your roses is an enjoyable and inexpensive practice that yields cost-free new plants and qualifies you as a real gardener. Here’s the process.

When your rose has finished blooming and entered dormancy, cut 6 to 8-inch-long pieces of flexible, pencil-thick new wood, removing the leaves except for a few at the top.

Fill nursery pots with 6 inches of dampened garden mix, with a good measure of perlite for excellent drainage.

Stick the cuttings into the pots, with at least two leaf nodes in the soil.

Put the pot in a plastic bag, seal the bag to maintain high humidity and place it in a sunny spot with some shade during the hottest part of the day.

Open the bag every few days to check that the soil remains moist (not wet).

After about two weeks, the cutting will develop roots and new growth and be ready for a new home.

Adding roses to the garden

The ideal time to add roses to your garden is during the dormant season, which runs from November to March. Garden centers and mail-order suppliers offer both bare-root and potted roses, 2-year-old plants ready to bloom in the following spring.

Bare root roses are less expensive than potted roses for mail-order purchases because they are lighter in weight and cost less to ship. Because they are dormant, they have no difficulty resting during the buying season.

The varieties offered for purchase can be so numerous as to become bewildering. When preparing to buy roses, plan where you will install the plants in your garden. Roses need light, so select on sites with at least six hours of daily sunlight exposure and good drainage.

Consider the size of the plant that would be appropriate. Many roses have sizes within 3 to 5 feet in height and width, but some will grow to smaller or larger sizes. The plant labels or online descriptions should provide the dimensions of the mature plant.

When considering a climber or rambler, keep in mind that roses do not have tendrils or suckers, as do some other climbing plants, so you will need a trellis or other form of support for the plant. As noted above, these plants will need training, particularly during their first three years of growth, to provide an attractive form and many blossoms.

Many of the modern garden roses are grafted varieties. A desirable bloomer has been grafted on a rootstock that supports vigorous and rapid growth of the plant. That’s good in several respects, but grafted roses can be taken over by “suckers,” unwanted canes rising from the rootstock.

I prefer “own root” roses, plants not grafted on a rootstock. I appreciate the character of a pure variety and don’t enjoy removing suckers.

After considering your intended sites, exposure, plant size and support requirements, the buying process still involves choices of plant type. Hybrid tea roses are very popular, but there are many others, i.e., floribunda, grandiflora, polyantha, etc.

Then, there is the choice of blossom color. A particular color might complement other plants in your garden or be pleasing for its singular appearance.

Rose growers often pursue overall approaches to their rose collection, focusing on, for example, color combinations, antique (or heritage) varieties, newer introductions, etc. The range of choices is very significant, so a plan could guide purchasing decisions.

Advance your garden knowledge

Roses have been enormously popular garden subjects, so there are many sources of information, books, magazines, websites, etc., to support the successful cultivation of roses in your garden.

The premiere online resource is the website of the American Rose Society (rose.org), with extensive information about all aspects of roses. The Monterey Bay Rose Society (montereybayrosesociety.org) shares expert information and recommends Easy Roses for California’s Central Coast.

Some principal rose suppliers have useful websites describing specific varieties, video presentations on rose cultivation, etc. Some helpful websites include jacksonandperkins.com, heirloomroses.com and highcountryroses.com.

For more targeted information, visit YouTube and search for your current interest: “propagating roses,” “cultivating roses,” “pruning roses” or other options.

Enjoy your garden and particularly your roses!

Tom Karwin is a past president of Friends of the UC Santa Cruz Arboretum and the Monterey Bay Iris Society, a past president and Lifetime Member of the Monterey Bay Area Cactus & Succulent Society and a Lifetime UC Master Gardener (Certified 1999-2009). He is now a board member of the Santa Cruz Hostel Society, and active with the Pacific Horticultural Society. To view daily photos from his garden, facebook.com/ongardeningcom-56651176 3375123. For garden coaching info and an archive of previous On Gardening columns, visit ongardening.com.