As farmers, we can do everything right—choose the best varieties, irrigate correctly, and manage our orchards with precision—but ultimately, we are still at the mercy of the climate. The past year has been a stark reminder of this reality.

As commercial mango and avocado farmers in Limpopo, South Africa, we have been farming since 1990, but 2024 was one of the toughest years we have faced. In winter, we experienced the coldest temperatures in over 30 years, dropping as low as -4°C. This was devastating for our new developments, as flowers and early fruit sets were burnt away by the cold. Then, in December, a brutal heatwave struck, with temperatures soaring above 50°C for seven consecutive days. Despite our best irrigation efforts, the extreme heat and lack of rain caused significant fruit drop.

When facing such challenges, it’s easy to lose hope. However, there are strategies to help protect your trees and harvests during extreme temperature events.

Protecting Your Orchard from Extreme Cold

  1. Site Selection and Windbreaks (one of the most important factors):
    • Plant orchards in locations less prone to frost accumulation-low lying areas are risk areas.
    • Use natural or artificial windbreaks to reduce wind chill effects- in windy areas – like Hoedspruit and The Cape
  2. Clear all obstacles that prevent cold drainage:
    • Cold air flows like water, keep that in mind when looking at your fields.
    • Make sure that cold air can ’flow out’ of your blocks.
    • Keep this also in mind when deciding on row direction.
  3. Mulching and Soil Moisture Management
    • Apply thick mulch around the base of trees to regulate soil temperature.
    • Keep soil slightly moist before a frost event, as moist soil retains heat better than dry soil.
  4. Covering/Spraying Young Trees
    • Use frost cloth, plastic tunnels, or other coverings to protect young and vulnerable trees from severe temperature drops.
    • Do a K and Si foliar spray when a cold spell is expected.
  5. Heating and Smoke Practices
    • In extreme cases, consider orchard heaters, controlled burning, or sprinklers to mitigate frost damage.
  6. Timing
    • Spray with Silica/Potassium mixed with mildew fungicides for limited protection.
Fully grown mango tree destroyed by tempretures below zero degrees.
Dead cambium of a young mango tree.
Early Dec, when the heatwave was only getting started.
Strong Macadamia leaves withering away from the heat.

Protecting Your Orchard from Extreme Heat

  1. Irrigation Management
    • Water deeply and consistently before and during heatwaves to reduce plant stress.
    • Use drip irrigation to ensure water reaches the roots effectively.
    • Measure soil moisture content at least 3 times a week with multiple methods, physical moisture testing, tensiometers, probes can be used.
  2. Mulching for Moisture Retention
    • Apply organic mulch to prevent excessive evaporation and keep the root zone cool.
    • Mulching is a great way to manage evaporation.
  3. Canopy Management and Shade Protection
    • Keep tree canopies well-structured to provide natural shade.
    • In extreme conditions, consider installing shade nets over young orchards.
  4. Soil Health and Organic Matter
    • Improve soil organic content to enhance its water-holding capacity and resilience to heat stress.
    • Mulching Mulching Mulching! Mulching over the long term (years) will build your soil health exceptionally well.
    • Adding other organic matter, like composted manure is also great, just make sure of your soil labs and the nutrient content in the composted manure. It should align with you soil needs and not shoot certain elements through the roof.
  5. Chemical Protection
    • Several applications will be necessary. Starting when fruit is golf ball size.
    • Si based products can be sprayed to help, especially- on the N/W side of the trees to give protection of fruit against sunburn.
  6. Monitoring and Adaptation
    • Use temperature sensors and weather forecasts to anticipate extreme weather events.

Adjust orchard management practices based on changing climatic patterns. Eg. Timely spraying with sun protection chemicals.

New development of 2024: The cold was too much, all the trees had to be replanted.

Conclusion:
Extreme weather events are becoming more frequent and unpredictable. While we cannot control the climate, we can take proactive steps to protect our orchards and ensure long-term resilience. Our experience in 2024 reinforced the importance of adaptability and preparation. Farming is a test of patience and perseverance, but with the right strategies, we can continue producing high-quality fruit, even in the toughest conditions.

If you’re looking for advice on selecting resilient tree varieties or improving orchard management, we’re here to help.