- Water deeply, so that you wet the entire root zone. Light sprinkling does little good.
- Get down and dig in the dirt. If the top 2 to 3 inches of soil are dry, you need to water.
- Reduce disease problems by watering the soil, not the leaves. Roses can benefit from overhead watering once in a while, especially in dry summer climates where black spot isn’t usually a problem; however, make sure that you water early enough (in the morning on a sunny day is ideal), so that the foliage can dry before nightfall.
- Mulch! Mulch! Mulch!
Start with a watering schedule: Water once every five or six days, for example. If you live in a hot, dry climate, make it every two or three days. Watch the plant carefully and check the soil often, especially when you get to the end of the period. If the soil is bone dry about 2 to 3 inches below the surface at the end of your test period, you need to water. If the soil is still moist, wait a few days and check again. If the rose’s foliage ever starts to look dull or droopy, you’ve definitely waited too long.
Water deeply, so that the entire root zone gets wet — for roses, that means to a depth of at least 18 inches. How far a given amount of water can penetrate into the soil depends on the soil type.
Two tools can help you fine-tune your watering schedule. The first is a soil probe — an approximately 3-foot-long hollow metal tube about an inch in diameter that removes a small core of soil from the ground. By examining the soil core, you can tell how deeply you’re watering or how dry the soil is. The second useful tool is a rain gauge. It can tell you exactly how much rain has fallen, and you can adjust your watering schedule accordingly. You can purchase soil probes and rain gauges through the irrigation supply stores listed in your local telephone directory.
You can use a number of methods to water roses. The key is to apply the water only over the soil where the roots are at a slow and steady pace:
- Build a basin: Build a 3- to 6-inch-high basin of soil around the plant and fill it using a handheld hose. Make sure that the basin is wide enough to hold the amount of water your rose needs. The basin should be at least 18 inches wide for new plants, and at least 36 inches wide for really big roses. You may have to fill the basin twice to get the water deep enough.
- Use sprinklers: Many types of sprinklers are available.
- Use drip irrigation: Drip irrigation is a particularly useful watering system for areas that are dry in summer, for areas where water shortages are common, or for busy gardeners who don’t have time to water as often as they should. Most drip irrigation systems are built around 3⁄8- to 1-inch black tubing and specifically designed emitters. The emitters drip or spray water slowly — no faster than the soil can absorb it — and only wet the root area. Less wet ground means fewer weeds.
