Growing Roses in Warmer Climates: Strategies for Success

Roses are beloved worldwide, but they can present unique challenges in tropical and subtropical climates. In a recent video, Jason from Fraser Valley Rose Farm explored how to grow roses in areas with intense heat, high humidity, monsoon seasons, and no true winter dormancy. While his expertise is rooted in a cooler, temperate climate, Jason provided valuable insights into how gardeners in warmer regions can adapt their rose care strategies for success.

Understanding the Challenge of Warmer Climates

Roses, traditionally northern temperate shrubs, thrive in climates with cold winters that enforce a period of dormancy. This dormancy helps roses recover from pest and disease pressures and store energy for robust spring growth. In warmer climates, where roses grow continuously without rest, gardeners face challenges like increased fungal diseases, pest persistence, and heat stress.

Managing Intense Heat and Bright Sunlight

Hot seasons can be a major stressor for roses, but careful planning can help them endure and recover effectively:

1. Provide Shade: Strategic planting can shield roses from the harsh midday and afternoon sun. High dappled shade, such as that from trees or shade cloth, can protect plants during peak heat while allowing enough light for healthy growth.
2. Deep Watering: Roses require consistent soil moisture during hot periods. Superficial watering won’t suffice; a deep soak ensures water reaches the root zone. Jason recommends watering thoroughly for several minutes and checking soil moisture by digging near the roots.
3. Mulching: A thick layer of mulch helps retain soil moisture and keeps roots cool. It also reduces competition from weeds and can improve overall soil health.
4. Avoid Stressful Practices: Activities like heavy pruning, pesticide applications, or excessive fertilizing during hot weather can shock already stressed plants. These tasks are better suited to cooler seasons.

Tackling High Humidity and Wet Seasons

High humidity and rainfall can create ideal conditions for foliar fungal diseases like black spot and powdery mildew, as well as issues with flower formation. Here are strategies for managing these conditions:

1. Focus on Drainage: Standing water around rose roots is a quick path to plant decline. Ensuring well-drained soil is essential, especially in areas with heavy rainfall or monsoon seasons.
2. Improve Air Circulation: Prune roses into an open vase shape to create space around each stem. This promotes airflow and helps foliage dry quickly after rain, reducing fungal infections.
3. Leaf Maintenance: During rainy seasons, remove diseased foliage promptly to prevent infections from spreading. At the end of the season, clean up fallen leaves and replace mulch to minimize overwintering pests and pathogens.
4. Boost Fertility Post-Rain: Heavy rains can leach nutrients from the soil. After wet seasons, replenish fertility with balanced fertilization to help roses recover and thrive.
5. Use Fungicide Alternatives: For fungal control, cultural methods like pruning and cleaning are often effective. If needed, treatments like potassium bicarbonate or neem oil can be used, though temperatures should be checked to avoid phytotoxicity. Jason advises against using sulfur with oil-based products.

Choosing Roses for Warmer Climates

Not all roses are well-suited to tropical or subtropical conditions. Old garden varieties like Albas and Centifolias often struggle in warm, humid climates due to their need for winter dormancy. Instead, roses with Asian ancestry, such as Chinas and Teas, tend to perform better. Many modern hybrids, including floribundas and hybrid teas, have inherited heat tolerance from these species.

Here are some top recommendations for roses that thrive in warmer climates:

• Belinda’s Dream: This medium pink shrub rose boasts large, double blooms with a moderate fragrance. Developed in Texas to withstand hot temperatures, it exhibits strong disease resistance, making it ideal for warm climates.
• Elina: Also known as ‘Peaudouce,’ this light yellow hybrid tea rose features large, mildly fragrant blooms. Its robust growth and disease resistance make it adaptable to various climates, including warmer regions.
• Aloha: A vigorous climber with pink-apricot blooms, ‘Aloha’ is known for its hardiness and ability to thrive in diverse conditions.
• Don Juan: This dark red climbing rose is celebrated for its strong damask fragrance and large, velvety blooms. It performs exceptionally well in warm climates, showcasing its best colors in areas with warm nights.
• Beverly: A hybrid tea rose with light pink, classic-shaped flowers and an exceptional sweet citrus fragrance. ‘Beverly’ is noted for its disease resistance and repeat blooming, making it a reliable choice for warmer climates.
• Julia Child: Known in the UK as ‘Absolutely Fabulous,’ this floribunda rose displays golden butter-colored blooms with a sweet licorice fragrance. It is heat tolerant and has excellent resistance to blackspot and mildew, making it a popular landscaping plant in warmer regions.
• Cinco de Mayo: This floribunda rose offers unique smoky lavender and rusty red-orange blooms with a mild fragrance. It is very disease resistant and blooms profusely, making it well-suited for warm, humid climates.
• Old Blush: An old China rose with pink blooms, ‘Old Blush’ is renowned for its resilience and ability to thrive in warm climates, often blooming continuously throughout the season.
• Sombreuil: This climbing rose produces creamy white, fragrant blooms and is known for its vigor and adaptability, performing well in warmer climates.
• Gruss an Teplitz: A robust shrub rose with crimson blooms and a strong fragrance, ‘Gruss an Teplitz’ is appreciated for its heat tolerance and continuous flowering in warm climates.

These roses are celebrated for their ability to withstand the challenges of warm, humid environments, offering both beauty and resilience.

Conclusion: Thriving with the Right Approach

Growing roses in warmer climates requires thoughtful adjustments to traditional rose care. By providing shade, managing water wisely, pruning for air circulation, and selecting heat-tolerant varieties, gardeners can overcome the challenges of heat and humidity. Jason’s advice underscores the adaptability of roses and the importance of tailoring care to local conditions.