Heat stress symptoms
Summer heat can be as damaging as winter cold. Here are some symptoms of heat-stress damage and some strategies for surviving the summer.
WILTING AND STUNTED GROWTH — Plants that exhibit these symptoms, such as fuchsia, are in need of water and shade. If a plant is exposed to prolonged periods of heat stress, the new growth will be smaller than the old and eventually the root system will shut down.
DROOPING OR ROLLED FOLIAGE — Another mechanism plants employ to protect themselves from heat is to roll their leaves and let them droop. Commonly seen on rhododendrons, this allows the plant to reduce its leaf surface area that is exposed to the sun. If left under these conditions for a long time the plant will eventually die.
To prevent these types of heat stress, place plants appropriately in your garden. If you have plants that are sensitive to summer heat, put them in a location that receives morning sun and afternoon shade, like an eastern exposure. This placement is also good for plants that suffer leaf scorch, like hosta.
Keep plants well mulched; organic mulch shades root systems and retains soil moisture. Rock mulches tend to add heat to the root zone and don’t conserve moisture as well. Also keep plants well watered. Using drip-irrigation lines can increase moisture without requiring you to stand out in the heat.