How Much Water Do Roses Need?
It’s rose-growing season! As we move further into spring and closer to the heat of summer, it’s helpful to look at our roses and their water needs to ensure that we water efficiently and for the healthiest plants. So, how much water do roses need? Here, gardening expert Katherine Rowe explores the basics of rose watering and the variables to consider in your garden.
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The right rose in the right place is a forgiving plant and a gorgeous garden feature. Roses adapt to a variety of conditions and, depending on the rose, thrive with a few best cultural practices in place. Water is essential to rose health, and efficient watering is vital for us gardeners.
Roses grow best in consistently moist, organically rich, well-draining soils. Proper watering ensures nutrient delivery and circulation from the base of the roots to the tips of the stems for healthy, floriferous plants. Depending on the water available in your area, they’ll benefit from regular moisture during the active growing season.
Once established, roses are relatively carefree and sustainable with average rainfall (they even tolerate drought) and with supplemental water during prolonged dry spells. Healthy soils and mulch are key components to their success in all conditions.
The Short Answer
How much water roses need depends on site-specific factors, including soil type, plant size, and seasonal weather. Aim for evenly moist soils surrounding the rose. Water deeply rather than frequently to promote a robust root system. Two to five gallons per week per rose is sufficient in moderate climates with average soils (the equivalent of one to two inches of water).
In hot, dry, or windy periods and sandy soils, increase watering sessions to two to three times a week for even soil moisture. A simple touch test tells us when soils are dry. Dig knuckle-deep (about one inch) into the soil to determine whether it feels dry, wet, or just right.
The Long Answer
Your garden is unique in many ways, including site-specific factors like soil type, exposure, weather, plant size, and placement. These are all variables to consider in determining how much water your roses need.
Roses grow and flower best in consistently moist soil. Once established, they grow without supplemental water with rainfall (and even in drought). The goal is to keep the soil evenly moist around the roots. Watering deeply—but infrequently—encourages a deep root system to support the plant during high heat and freezing temperatures.
Observing the plants and feeling the surrounding soil is the best way to determine if you’re watering enough. Underwatered roses wilt (as they’re apt to do in periods of extreme heat, too). Leaves turn yellow and crisp. Overwatered roses also exhibit yellowing leaves, which are soft and spongey. When the soil feels dry to the depth of one inch, it’s time to water.
How Much to Water
We’ll look at the variables that impact water amounts below, but generally, rosarians recommend two to five gallons of water per rose weekly, which is the equivalent of one to three inches of water per week.
Water needs relate to rainfall amounts. Cut back during rainy weeks, and pay attention to dry or windy spells and periods of intense heat for increased water needs. Add a session or two during these spells.
The goal of watering with two to five gallons at a time (some say two to three, others say three to five) is to achieve a deep soaking all around the roots. The ideal watering depth is 16-18 inches to moisten the surrounding soil. This depth promotes root growth and strengthening and improves overall plant health and vigor.
On the other hand, frequent shallow watering encourages roots that grow laterally and just beneath the surface rather than deep into the soil. Shallow roots impact plant stability, hardiness, and nutrient sources.
Soil Type
Soil type plays a significant role in the water needs of all plants. Fortunately, roses grow in a variety of soil conditions. Prime soils for roses are rich in organic matter and well-draining.
To irrigate efficiently, it helps to know how local soils absorb and retain water. A simple soil test (often available at your local university extension service) helps with this information. Typical soil types include blends of:
Clay soils
Clay has a slow absorption rate, slow drainage, and holds water. It needs up to three inches of water (4-5 gallons) at a time to penetrate the 16-18-inch root depth. Water permeates slowly through the clay, though retention is high. Clay soils may stay overly wet at shallow levels.
Loamy soils
This ideal soil contains organic material to aerate and retain moisture. Loams need about one and a half inches of water (2 gallons) to achieve a root depth of 18 inches.
Sandy soils
Sandy soils are the fastest-absorbing and fastest-draining. They dry out quickly. Sandy soils need about one and a half inches of water to infiltrate 18 inches deep but more frequently to attain regular moisture.
In poor soils (sandy or clay), incorporate three to six inches of compost derived from completely broken-down plant material. Compost helps with soil aeration, moisture retention, drainage, and nutrition. If your soil holds moisture and tends to stay wet, avoid overwatering roses (too much water or “wet feet” promotes root rot).
Seasonal Conditions
Roses grow actively from early spring through fall and require more water during the warm growing seasons, especially in hot conditions and periods of dryness. In spring and summer, water established roses once a week (and more if soils dry out). Water newly planted roses every few days.
Roses are dormant in the winter and won’t need supplemental water unless in warm climates or containers, and only then when the soil is dry.
Rose Type and Stage
For newly planted roses, water every two to three days to keep the surrounding soil moist. After about a month, start increasing the length of time between watering. Allow the roses to dry out slightly between sessions.
Established and mature roses will be well-adapted to your soil type and watering conditions. In moderate climates, natural rainfall is enough to sustain them. Supplemental water, especially during dry spells or prolonged drought, can ease plant stress with regular moisture.
Pay special attention to roses in containers, which dry out more quickly. Terracotta and clay pots are porous and dry out faster than glazed or synthetic materials. Roses in containers will appreciate one to two gallons per session, depending on the pot and plant size.
Due to their size, large roses, like vigorous climbers and ramblers, use more water than shrub roses or hardy landscape roses. A good rule of thumb is at least two gallons per session, increasing sessions in hotter periods.
Climbing roses along walls and fences sometimes receive reflected heat from those surfaces. The structures may also block rainfall (a rose planted on a pillar under an eave, for example), so observe plants and feel the surrounding soil for moisture content and water needs.
When to Water
Water early to prevent diseases like powdery mildew and blackspot. Morning water gives leaves and flowers a chance to dry under the day’s sunshine.
Early watering allows resources for the rose during the heat of the day. They’ll benefit from the deep soaking before evaporation from the soil and transpiration (natural water loss through the leaves’ pores).
How to Water
There are many “how-to” recommendations for watering roses. To prevent diseases and pests, avoid overhead watering and the routine splashing of leaves and flowers.
We know roses benefit from rain, so overhead water is not technically detrimental. When using spray heads, disease prevention is at its highest when watering occurs in the morning, and leaves have time to dry out during the day. Skipping overcast days and refraining from evening watering is important.
Water at the base of roses, slowly and deeply, pausing if water starts to run off. The idea is to give roots a good soaking session. A watering can or bubbler fitting on a hose are good options. Drip irrigation and soaker hoses are efficient in low volume with little runoff and consistent delivery.
To deter and displace insects during the active season, spray plants with a jet stream of water once weekly or as needed. Do this, too, in the morning so foliage dries out during the day.
The Value of Mulch
Maintain a three-inch layer of mulch year-round to retain moisture, regulate temperature, and suppress weeds around roses. Mulch cools roots in the summer and insulates them in the winter. Mulch also adds nutrients to the soil as it decomposes.
Apply fresh mulch in the spring—water well after mulching to keep it in place and promote retention.
Final Thoughts
Honing in on your rose-watering technique increases water efficiency and plant health. The great thing about growing roses (aside from their incredible blooms!) is their adaptability. Following basic cultural requirements for roses gives the best chance of success for a relatively carefree and gorgeous garden performer.