Cold weather in the subtropics
Winter is relatively mild in the Southern African subtropical regions. However, the months of June and July have been quite cold by subtropical standards, which may cause some problems with perennial and tropical plants with little cold tolerance. Sunny warmer daytime temperatures may worsen the cold damage. What are the signs that the plants are affected by cold weather?
Signs of cold or frost damage
Brown leaves, especially in places exposed to water and direct sunlight. Weathering stems or leaves and drying up of new shoots and flowers—or stunted growth and, in worse cases, death of the plants.
What can we do to prevent cold damage?
Plant evergreens in sheltered locations. You can use shade nets or move pots in sites protected by direct wind and sunlight. Higher canopy plants, walls, or shrubs in the property boundaries are cost-effective and convenient. The microenvironment will be relatedly warmers, and the soils will not dry out too quickly due to reduced transpiration. Adding composted manure and mulch keeps the soils nutritious, moist but not soggy.
Most importantly, the soils remain warm, allowing the plant roots to stay warm and moist. Keeping the tropical trees shorter will reduce cold damage from strong winds. Water the plants at least once or twice weekly. The pawpaw, Syzygium oleosum (blue Lilly pilly), Chayote, coffee and potted herbs thrive in the Subtropical Urban Eden despite the cold, windy nights.
Share any tips for protecting tropical plants from cold damage.