Sun, Humidity, And Spacing

The success of your roses depends a great deal on the conditions in which they are grown. Most roses need at least six hours of direct sunlight each day. They also need rich, well-drained soil, ample growing room, protection from the winter, spacing, good watering.

Although you can do little to change the basic climate of your garden, the odds are that you can find or create a small area where roses can thrive. Even the harshest environment offers locations that are sheltered from prevailing conditions, thanks to differences in vegetation, variations in terrain, or the proximity of buildings and other structures. For example, the warm and sunny south wall of a house can harbor plants that would perish if placed in the middle of a chilly, windswept garden.

If a favorable site for rose growing does not exist in your garden, you may be able to create one through small modifications, such as building a fence to shelter plants from the wind or cutting back surrounding foliage to admit more air and light. Your roses will be your companions for years to come, so it is worth making the effort to provide them with the best possible surroundings.

Sunshine

Roses need at least six hours of direct sun a day to grow and flower their best. It is better that the sunny hours occur in the morning than in the afternoon, since morning sun dries off the foliage early, reducing the chance of disease. Morning sun is also less likely than stronger afternoon sun to burn leaves and flowers, especially in hot climates.

Roses that are not receiving enough sunlight will show spindly growth and will have thin, weak canes. Leaves will be farther apart than normal and flower production will be poor. If these symptoms appear in your garden, you may be able to correct them by moving the plants, by trimming any nearby tree limbs that block the light, by painting an adjacent wall or fence white to reflect available light, or by using a light-colored mulch.

Some roses can grow in partial shade if you take some extra precautions. Locate your roses where they will not compete with other plants for food and water. Even though shaded roses do not grow as large as those grown in full sun, the spacing of plants should be the same. This ensures good air circulation-a necessity in shady areas, where disease organisms such as mildew can thrive. Before planting, work in extra compost or other organic matter to hold moisture and nutrients. But avoid the temptation to add extra fertilizer to compensate for the lack of light; since roses grow less profusely in reduced light, they need fewer nutrients. Overfertilizing is not only a waste of money, but can actually burn the roots and foliage.

Because the various classes of roses differ in their light requirements, you may get better results by planting another type. If your garden is too shady for modern roses, try one of the hybrid musks, which can grow and bloom in less sun than other types. Hybrid musks need about four hours of direct sun a day. Miniature roses, too, tolerate a little more shade than some of their larger cousins, and are happy in four hours of direct sun. Many climbers also grow happily in the filtered shade of a tree.

Humidity

When the air around roses is extremely humid, the incidence of disease rises, since the fungal spores that attack roses thrive in high-moisture conditions. For this reason you should select a site where air can move freely. But avoid a windy location, because rapid airflow can dry out roses and tear the flowers and foliage. In humid climates particularly, choose a spot where roses will not be closely surrounded by hedges, large plants, or walls that can constrict air movement. Where humidity is naturally low, you can raise it by reducing air motion, such as with a fence or other structure; by placing a coarse mulch on rose beds, which will evaporate a considerable amount of water into the air, or by watering often. Misting plants in the morning also raises the humidity around them.

Spacing

Because roses are demanding of sun, water, and nutrients, they should be placed where they will not be crowded by other plants. If possible, avoid positioning them at the bases of trees or where their roots will compete with those of other vegetation. If you must plant near a tree, locate your roses no closer than halfway between the trunk and the farthest spread of the tree limbs. Better still, place your rose completely outside the canopy of the tree. When planting roses near trees, prune away the lower tree limbs to improve air circulation and let in more light.

Keep roses at least 3 feet away from the bases of other shrubs. If your garden is small and this is not possible, dig a hole that is 24 to 30 inches wide and 24 to 30 inches deep, and install an underground barrier around each rose. Ideally made of plastic or metal sheeting (such as vinyl siding, aluminum, or sheet metal), an underground barrier will prevent nearby shrub and tree roots from invading the territory around the rose. It is easiest, of course, to put one in at planting time. But if you don't, you can excavate the soil at a later date, cut out the invading roots, and then install the barrier. Be sure the barrier is as close as possible to the edges of the hole, so that the roots of your roses can grow to their fullest. Where a large rose bed is situated near competing plants, you will find it easier to install the barrier around the entire bed rather than around each plant.

Roses can be interplanted with small shrubs, perennials, annuals, bulbs, and some ground covers, such as ajuga and periwinkle. Ivy, however, is usually too aggressive, growing into the rose plants and robbing them of fertilizer and water. Be aware that roses stationed among other plants need a little more fertilizer and water.

When planting roses near a building or a solid fence, set the plants out at least 18 inches from the structure to allow room for growth and air movement. In hot climates, try to avoid planting roses in front of a white wall or fence that can reflect burning light and heat. However, in cool climates or where light is low, planting roses near a reflective wall or fence can increase growth.