What Climbing Roses Require Direct Sunlight?

Every climbing or rambling rose (Rosa spp.) seen in nursery catalogs have one thing in common -- they all require at least six hours of direct sunlight each day. However, in summer's blistering afternoon sun, rose colors fade. It is best to locate your climbing roses where they have direct sun in the morning and dappled shade at mid-day. Afternoon shade promotes good bloom color, and morning sun dries out the dew so the rose has less chance of contracting a fungal disease.

Roses need the sun for energy, which is absorbed through their leaves in a process called photosynthesis. This process produces the sugars and oxygen the rose needs to build cell walls and continue to grow. The amount of sunlight supporting roses changes with the seasons. As the daily intensity and length of sunlight changes with the shorter daylight hours of fall, the plant's ability to absorb its energy through photosynthesis declines.

Climbing roses grown in direct sunlight with no respite from the afternoon heat need more attention than roses that only get morning sun. For the most part, roses are heat-tolerant, but it's important to keep the soil moist. They need deep watering to ensure moisture seeps down to the lowest areas of the root system. All roses are thirsty plants, and they lose their heat tolerance if the soil is allowed to dry out. Add 3 inches of mulch to help keep the soil cool and moisture levels constant. New transplants will need shading in the afternoon sun until they get established. Use shade cloth, cedar boughs, or even a sheet of cardboard to block out or filter the sun.

Climbing roses don't actually climb. They simply send out long vertical canes that need to be tied into a structure to keep them in order. Most climbing roses offer repeat blooms after the spring flush. Some of the best climbing roses that grow well in direct sunlight include "New Dawn" (Rosa "New Dawn") and "White Dawn" (Rosa "White Dawn"), both growing to 20 feet. Consider the vigorous "Miss Caroline Testout" (Rosa "Miss Caroline Testout") with its bright pink blooms; or choose the old favorite, "May Queen" (Rosa "May Queen"), which is an all-purpose climber. "Golden Showers" (Rosa "Golden Showers") puts on a cheerful display with large yellow blooms. All thrive in U.S. Department of Agriculture plant hardiness zones 4 through 10.

Rambling roses are also considered climbers, but their canes are less stiff, and they will grow both outward and upward, rambling and scrambling along fences and over arbors. Most offer clusters of flowers with no repeat blooms. "American Pillar" (Rosa "American Pillar") is an old standard, rambling to 15 feet along fence lines or over arbors. It's often paired with "Dorothy Perkins" (Rosa "Dorothy Perkins"), both hardy in USDA zones 4 through 11. "Minnehaha" (Rosa "Minnehaha") blooms later, useful in extending the blooming season. It is hardy in zones 4 through 9. The big ramblers such as " Kew Rambler" (Rosa "Kew Rambler") and "Adelaide d'Orleans" (Rosa "Adelaide d'Orleans") are vigorous and will cover an arbor within a few seasons. Both thrive in zones 5 through 11.

When choosing climbing roses for your garden, consider the bloom color and bloom type. In general, the deeper the bloom color, the less heat-tolerant the rose. Climbing roses with lighter-colored blooms, such as "Meg" (Rosa "Meg"), which is hardy in USDA zones 5 through 10, and "Swan Lake" (Rosa "Swan Lake"), hardy in zones 4 through 11, are tolerant of both full afternoon sun or partly shady conditions better than climbers with hot-colored blooms, such as the orange-flowered "Joseph's Coat" (Rosa "Joseph's Coat"), hardy in USDA zones 4 through 10, or the deep red "Sympathie" (Rosa "Sympathie"), hardy in zones 4 through 9. Climbing roses with single-petal blooms, such as "Lawrence Johnston" (Rosa "Lawrence Johnston"), which is hardy in USDA zones 4 through 9, or "Complicata" (Rosa Gallica "Complicata"), hardy in zones 5 through 9, are more shade-tolerant as well.