How often should I water plants during a heat wave?

The equation is simple: When it is hotter, plants need more water. Container plants may need daily or twice-daily watering in extreme heat, according to Iowa State University.

Experts recommend watering plants in the early morning or evening, when it’s cooler and less water will evaporate. However, “if your plant is dry, and the only time you can water it is 2 p.m., give your plant water,” Griswold said.Overwatering is still possible in hot weather, and some plant diseases thrive in hot, wet conditions, Griswold cautioned. Gardeners should follow the usual rule of thumb: Check the soil in the plant’s pot, as deep as is possible, and only add water if it is dry.Bottom watering is another good option for potted plants during a heat wave, said Karen Mitchell, a Purdue University College of Agriculture consumer horticulture extension specialist.

To do this, place a pot — with a hole in it — in a layer of water about an inch deep. Let it soak, allowing the roots to suck up the moisture and distribute it throughout the soil, until the soil feels moist toward the top of the pot when you touch it with your finger — usually between 10 minutes and an hour, depending on the size of the plant.