Drought Tolerance: The Amazing Plant Adaptations

Here comes the drought stress…

June first marks the beginning of Florida’s rainy season – although, it has not been that rainy lately. In fact, we’ve already received a couple of burn ban notifications from the Florida Forest Service. While our spring started off wetter than normal, the past couple of weeks have been dry. Some parts of my landscape are longing for rain, while others seem unaffected. As a result, this is the time of year I typically find myself irrigating certain parts of my landscape to prevent drought stress on some plants. Thankfully, by adhering to the principles of the Florida-Friendly Landscaping program, we can easily select plants with drought tolerance that withstand the hottest, dryest days in Florida. This allows our landscape to thrive, look beautiful, require minimal irrigation, and, importantly, demand less effort—a perfect combination for this lazy gardener.

Drought-Tolerant Plants

Drought-tolerant plants are truly fascinating. When thinking of the most drought-tolerant species, one might immediately picture plants from the desert southwest, such as rabbitbrush, cacti, acacia, agaves, and yuccas. However, these are not the only plants with impressive drought tolerance. Many of Florida’s native plants also exhibit a high degree of drought tolerance. Consequently, once established, many plants in our landscapes require no irrigation, even during severe drought periods. This resilience is due to specialized morpho-physiological characteristics that allow these plants to protect and conserve water.

Plant Adaptations

Plants employ various morpho-physiological adaptations to increase their drought tolerance, primarily aimed at reducing water loss. Strategies include different photosynthesis processes, hormonal regulation, osmotic adjustments, and changes in root morphology. Simply put, plants become adept at conserving water. One crucial strategy is the closure of stomata—tiny openings on leaf surfaces—during dry periods to minimize water loss.

Despite the complex adaptations that enhance drought tolerance, certain physical characteristics can help us quickly identify drought-tolerant plants. When browsing your local nursery, look for plants with thick, leathery, or hairy leaves, or those with thin, strappy leaves. The thick and leathery leaves will sometimes have a waxy cuticle – this helps the plant reflect away light/heat. This is like us wearing light colors in the summer rather than dark colors. Thin and strappy leaves reduce the overall surface area of a leaf, which minimizes water loss opportunities. Lastly, the hairy leaves shade stomata and reduce the plant’s direct contact with warm air. These attributes aid in temperature regulation and reduce water loss, helping plants endure warm, dry conditions.

Signs of Drought Stress

Surprisingly, part of the Florida-Friendly Landscaping™ program’s “water efficiency” principle involves encouraging plants to experience some level of drought stress rather than overwatering them. This approach promotes deeper root growth, enhancing plant resilience to drought. Signs such as folded leaf blades and changes in leaf color indicate when turfgrass needs watering, while wilting leaves and leaf loss indicate drought stress in shrubs and trees.

When to Irrigate…

Trees and shrubs generally require less frequent watering compared to turfgrass. If signs of drought stress appear, consider targeted irrigation only where necessary. Turfgrass and trees/shrubs should ideally have separate irrigation zones to prevent overwatering.

When to try Something New

If a part of your landscape consistently requires irrigation due to low drought tolerance, consider replacing those plants with drought-tolerant species. Use resources like online plant selection apps to ensure you choose the most suitable plants for your environment. Some favorite drought-tolerant plants include coontie palms, native lantana, rosemary, beach dune sunflower, blue daze, native clumping grasses, firebush, Texas sage, palmettos, hollies, and cedar trees.

Become a Lazy Gardener with the FFL Program

As a self-professed lazy gardener, I adhere to the principle of “right plant, right place.” If a plant doesn’t thrive in its environment, it’s not the right fit. My aim is to cultivate a landscape that is resilient, low-maintenance, and beautiful, requiring minimal supplemental watering. By doing so, I hope to contribute to the conservation of Florida’s water resources for crucial sectors like agriculture, fisheries, springs, estuaries, and tourism, all vital to the state’s economy. Thankfully, achieving this goal is straightforward with the guidance of the Florida-Friendly Landscaping™ Program.

Other Drought Tolerant Resources

How to Reach Us!

If you have any questions about planting, selecting, and maintaining your garden, reach out to our Master Gardener Volunteer Help Desk at Nassau County’s extension office for more tips. For all your questions about managing your gardens and landscapes, you may reach out to the Nassau County Master Gardener Volunteers at NassauMGV@ifas.ufl.edu.