Can I Water Roses During Heat Waves?

A robust rose bush covered in blooms

Roses (Rosa spp.) can be difficult plants to please, though many gardeners find them to be well worth the fuss thanks to their showy, intricate blooms. Roses love temperate weather and are likely to suffer in times of extreme summer heat. Following a few basic care tips and watering regularly can help to ensure a healthy, long-lasting plant.

Watering

Roses require frequent watering if they are to survive a triple-digit heat wave. Water roses early in the morning, watering deeply and thoroughly. Water again in the afternoon if the plant is in a container and in a location that receives direct sunlight all day. If the heat is dry, rather than humid, spray foliage as well as the soil. Though wet foliage normally places the rose at risk for disease, wet foliage can benefit the plant in extreme dry heat, and will dry quickly.

Mulch

Mulch can greatly aid a rose during a heat wave, as it retains moisture in the soil and regulates soil temperature. Both potted roses and garden roses benefit from mulch. Apply a thick layer of spaghum moss to container roses, and a 2- to 4-inch layer of shredded bark, wood chips or dry grass clippings to garden roses. In addition to regulating temperatures, mulch also helps to prevent weeds from growing near the plant.

Location

In general, roses require a full day of sunlight to truly thrive. In extreme heat, however, all-day sun can quickly lead to scorched leaves, wilted flowers and a generally unhappy-looking plant. Move potted roses to an area with afternoon shade to give the plants some respite from the scorching sun. Place potted roses on concrete, rather than asphalt, as asphalt retains far more heat than concrete.

Fertilizer

All roses can benefit from fertilizer, which helps to encourage flowering and general plant health. A healthy rose plant with a strong foundation is less likely to succumb to diseases and pests, which are more likely to attack when the plant is stressed. Fertilize once in the spring with a general purpose fertilizer, and again after the first flush of blooms in mid-June. Do not fertilize after August 15, as this encourages the plant to produce new, vulnerable growth which is likely to be damaged in the winter.

References

• Green Harvest: Organic Rose Care
• University of Illinois Extension: Water, Mulch and Fertilizer