Whether your rose is a climber, a shrub, a hybrid tea, or a species, it will need water; the development of flowers and rose hips depends on a regular supply of moisture. If watering is done improperly, however, it can be harmful. For example, a harsh jet of water from a hose aimed at the top of a root ball can rapidly wash away soil, exposing roots to drying, damaging sun and wind. Or, if roots are left standing in waterlogged soil, they are likely to rot, eventually killing the plant.
How Much and When
Though many roses are resilient and reliable once established, getting them to that point requires special attention. Watering, again, is crucial to the process. Plant your roses in early spring to avoid heat surges, which can harm plants as they establish themselves. When you do water, be sure to saturate the soil. A new planting should receive at least an inch of water per week during dry weather. This kind of deep watering will promote strong root growth that will extend further into the soil and help your roses through droughts and heat once they have matured. Water early in the morning; this allows the plant foliage to dry out during the day (dry foliage is less prone to diseases and harmful fungi). Avoid watering at sunset.
What to Use
There are many types of watering devices available. Here are some things to keep in mind when picking one that's right for your roses.
Water wands can extend your reach by 24 to 48 inches. If you have only a few new plants in a small area, you may want to use one. They attach to any standard garden hose and come with an adjustable valve that can regulate the flow of water.
Overhead sprinklers come in many shapes and sizes. Use them when you have a large area to cover. Impulse sprinklers can cover up to 80 feet in diameter; oscillating sprinklers adjust for coverage from 75 to 3,600 square feet. Your choice will depend on the size of your flower beds.
Drip irrigation is the most efficient way to water and can also be ideal if you garden at a weekend home. Porous, flexible hoses gradually release water through the hose surface and directly soak the soil below. Water flow is timed and pressure-controlled at the source, usually a spigot from a house or main water source. Many systems now feature digital controls that can be programmed for several days' worth of watering cycles.
Choosing and preparing the site for roses is as important as choosing the right plant. Roses need full sun and plenty of it--at least 5 to 6 hours a day. Some species and old-fashioned roses, will tolerate dappled shade. Give roses enough space for good air circulation and enough light to discourage fungal diseases.
Space roses to allow for their full diameter of growth: If you are planting shrubs that will reach 3 feet in diameter, space them 3 feet apart, measuring from their centers. You can adjust the spacing, depending on the mix of plants. For instance, climbers can be placed somewhat closer to nonclimbers, accounting for their upward growth. When using roses in mixed borders, try not to crowd perennials around the base of the roses.
Roses are heavy feeders--they need a lot of nutrients to look their best. Nutrients can be supplemented through fertilizers, but nothing beats a well-prepared garden bed. To achieve this, follow the suggestions below.
Start with a soil test to determine the pH level. Roses prefer it slightly acid, 6.5 pH. Call your local cooperative extension service to ask about soil testing kits, and for advice on making appropriate adjustments if the level is significantly high or low. If only a minor adjustment is needed, you might try organic amendments such a leaf mold, compost, and aged manure can help balance the acidity or alkalinity of soil. Such amendments also improve the soil structure, making it better able to retain moisture and nutrients, and to drain faster, both of which are essential for roses to thrive.
How much organic matter should you add? By adding one-third of the total volume of soil you are amending, you'll increase the overall quality of your soil substantially. In other words, if you are amending your soil to a depth of 12 inches, add 4 inches of aged manure, compost, leaf mold, or a combination of these.
Some people swear by seaweed, such as kelp, and particular aged manures, such as chicken manure, for better roses. Visit botanical gardens, nurseries, and rose gardens in your area, and ask what works in those places.
And don't stop once you have planted. Soil improvement is an ongoing project. Mulching with leaf mold or compost every spring and fall improves the soil and replenishes its nutrient levels, keeping those hungry roses happy.