Tamara Kelly SHOULD OUTDOOR PLANTS BE WATERED EVERY DAY IN HOT WEATHER? Should you water outdoor plants more often in hot weather? It's the hot topic of the day as we start to feel the effects of the heatwave. Plants will need to be watered more regularly in hot weather, but not necessarily every day – unless they're in a container or a wallside border that restricts their root growth. "It all depends on factors like soil type, plant maturity, and location," advises professional gardener Jane Dobbs.