Issue 67 How to Know When to Water

Ever wondered how to tell when you need to water your plants?

In Garden Gate issue 67, we talked about using the drooping leaves of some plants, like ligularia and New Guinea impatiens, as a sign it’s time to water. Many plants’ leaves will wilt in the heat of a summer day. But if the plant is still wilted in the morning after a night of cooler temperatures, it’s a definite sign of water stress. Here are a few more “indicator plants.”

Plant name Comments
Astilbe Astilbe spp. Drooping leaves
Astrantia Astrantia major Drooping leaves
Birch Betula spp. Drooping leaves
Coleus Solenostemon spp. Drooping leaves
Dogwood Cornus spp. Drooping leaves and stems
Impatiens Impatiens spp. Drooping leaves and
Ligularia Ligularia dentata Whole plant droops dramatically
Plectranthus Plectranthus spp. Drooping leaves
Plumeria Plumeria spp. Drooping leaves
Primrose Primula spp. Drooping leaves
Squash Cucurbita hybrids Drooping leaves
Tomato Lycopersicon hybrids Drooping leaves and stems

Remember that the best way to water is early in the day and close to the soil with a watering wand, drip irrigation system or soaker hose. Much of the water from a sprinkler used on a sunny or windy summer day evaporates before it can do the plant any good.