A soaking once a week helps roses develop strong roots. Watering deeply also reduces the amount of weeds and makes for a healthier, more beautiful plant. Water in the morning to reduce evaporation.
A full-size hybrid tea rose in typical soil requires 6-9 gallons of water per week. A deep soak is the best way to deliver this to the plant.
Deep Watering
Roses need plenty of water to grow, flower, and maintain their overall health. The correct amount of water transports nutrients to the roots and keeps leaves turgid for photosynthesis.
Generally speaking, two to three inches of water per week (4 to 5 gallons) is enough to sustain most roses in temperate climates. However, the size of the plant and soil type can influence how much a rose needs.
Newly planted roses and roses in containers may need to be watered more frequently than established bushes. The need for water also varies depending on the season, especially in spring and summer, when growth and blooming are peaking.
The best way to determine if your roses need water is to feel the soil. Stick your fingers 1 to 2 inches into the ground and if it feels dry, it’s time to water. You can also use a moisture meter to check the depth of the water.
It’s a good idea to water early in the day to minimize evaporation. It’s important not to overwater as this fills the pores in the soil and cuts off oxygen to organisms that help convert the nutrient into forms plants can absorb. If the roses seem to wilt in the afternoon, it’s usually a good sign that they’ve had enough. However, if the wilting is dramatic and quick, it’s likely that they need more water.
Drip Irrigation
The best way to water roses is to use a drip irrigation system that delivers water directly to the soil. This method prevents splashing on the leaves, which helps avoid fungal diseases, and it allows for a slow consistent flow of water which encourages deep root growth and improves drought resistance. For those who don’t have a timed watering system, using a soaker hose is a good alternative. Just be sure that the water reaches a depth of 12 to 18 inches and avoid getting the foliage wet.
Overwatering may result in yellowing near the base of the plant, mushy or blackened roots, wilting, drooping and falling leaves, slow growth and lack of blooms. Overwatering can also promote fungal disease problems such as mildew. If you notice these symptoms check the soil moisture and adjust your watering schedule, improve drainage if necessary, add or refresh mulch to retain soil moisture and suppress weeds, and avoid over fertilizing.
To test how often to water, stick a soil probe in the ground near the roots and make sure that it’s moist. Water in the morning, if possible, as this reduces evaporation and gives the foliage a chance to dry before nightfall when temperatures cool. Watering in the evening can leave moisture on leaves overnight, which will promote fungal diseases.
Hand Watering
For a general guide, water roses every two to three days during hot weather (or as needed) with a deep soaking. It’s best to use a watering can with a showerhead-style spout to better control the flow and prevent eroding the soil around the roots; a garden hose with a sprayer or sprinkler is acceptable. If you are using a hose, avoid a jet or high-pressure stream that can erode the soil and splash the foliage which can encourage disease problems.
When determining how often to water, touch the soil to check its moisture level. Roses with loose, well-drained soil need less frequent, but deeper, watering than those in clay or sandy soils that dry out quickly.
Newly planted roses require extra water to establish themselves. When the temperature is high, they need water more frequently than established plants, and it’s important to water so that the water reaches the root zone.
Wilting is a good indicator that a plant needs water. It is caused by a process called transpiration where the plant is losing water through its leaves. This can occur when the roots are underwater or if watering is too light. A wilting rose is starving its roots of oxygen so it can’t keep up with its watering needs. Count the number of days since your last watering and if the rose has begun to wilt, it is time for another deep soak.
Mulching
A thick layer of mulch is beneficial for all garden plants, but it’s particularly important for roses. Mulch can help retain moisture, regulate soil temperature, and suppress weed growth. It can also provide a valuable source of organic matter that helps improve soil structure and aeration, especially in heavier clay or sandy soils. Organic matter also enriches the soil with a continuous supply of nutrients, which makes mulching an excellent alternative to fertilizer.
When applied properly, mulch can reduce the frequency of watering, allowing the soil to soak deeply. It can also prevent water splashing on leaves, which helps control fungal diseases. Mulch can also reduce the impact of extreme temperatures on roses, keeping the ground warmer in summer and less icy in winter.
Choose an organic mulch, such as compost, shredded leaves, or straw. Organic materials decompose slowly and naturally, adding valuable nutrients to the soil. If you have a well-aged compost pile, you can use the material directly as a mulch, though be careful not to add meat or grease wastes because they may contain phenols that inhibit plant growth. Other organic materials, such as hay and grass clippings, can be used for short-term winter protection but need to be refreshed frequently because they often contain weed seeds and don’t decompose very quickly.
