Wilt Proofing

It has been hot, hot, hot and dry, dry, dry. Storm clouds have rolled in spitting a few rain drops and if we are lucky a quick sometimes heavy shower. Instead of permeating the soil, most of the water just runs off providing very little to us gardeners. 

It has been said that when temperatures climb men sweat and ladies wilt.  Just as humans perspire plants have the self protective mechanism known as transpiration to survive excessive heat causing the leaves and flowers of many plants to drop in hot weather.  Plant cells are largely made up of water. When these cells are full the plant's stems stand upright; leaves expand to receive sunlight and the plants roots make nutrients available. However, as the soil dries out it becomes increasingly difficult for the plants roots to provide proper plant function. Lack of water can result in reduced flowering, leaf drop, and increased pest problems. 

While we have no control over the weather, how we plan or maintain our gardens is key to minimizing its negative effects on our plants. 

  • This starts with choosing well-suited plants for the growing conditions. For instance, in dry areas, consider using drought tolerant plants; perennials such as agastache, butterfly weed, sedum or else yarrow or the annuals lantana, celosia, zinnia or ageratum. 
  • Plants that are newly planted should also be given regular moisture until they become established to bloom through hot, dry conditions. Understand also that some annuals with broad leaf surfaces and all kinds of hydrangeas are well known for wilting. Try to plant them in areas with morning sun and some afternoon shade. 
  • Wherever possible, improve soil conditions before you plant by adding organic matter so that plants can send out strong, abundant roots to better deal with stress. 
  • Water only when needed. If garden plants are watered too frequently they may develop shallow root systems making them vulnerable to drought. Even during hot, dry weather landscape plants should not need dampened every day. When watering, the objective is to encourage the plants roots to search deeply for moisture. Generously soak around the plants root zones. This often takes two to three times longer than just observing a wet soil surface. Water should penetrate the soil at least six to eight inches. A simple way to determine whether your garden is getting enough or needs water is to poke a finger down into the soil. Dryness a couple of inches down is a sign to water. For the reason that a soil's surface dries out too quickly, simply touching it will be a poor watering indicator. 
  • Early morning is the ideal time to water. Cooler air decreases evaporation and also gives the leaves of plants susceptible to fungal diseases, such as roses or dahlias, a chance to dry quickly. Late afternoon is the next reliable time for watering but wetting the plant's leaves should be avoided since they will have less chance to dry in the cooler evening air encouraging fungal growth. And lastly, by all means mulch. Most water lost from landscape plantings is from soil evaporation. 
  • Mulch acts as a sunscreen retaining moisture and reducing the need to water. 

Prolonged hot sun and dry soil are the primary causes of wilting but factors including high humidity or wind can cause this problem as well. Nevertheless, healthy plants grown in nutritious soil then watered and mulched properly are the best line of defense against the challenges hot, hot weather can cast upon us.