Different plants may be better suited to new weather patterns. Mr. Simmons said that a few outlets were already selling the native species mixes that the Lady Bird Johnson Wildflower Center was working on, and they were proving popular.

In Britain, “gardeners are starting to select more drought-tolerant species, and we are likely to see changes in the planting palette over coming years,” said Tim Entwisle, director of conservation, living collections and estates at the Royal Botanical Gardens in Kew, England.

More important than technology, however, is common sense, including the ability to use new technology properly, and attention to saving water. “Like all good gardeners, Kew staff adjust their watering in response to rainfall and evaporation,” Mr. Entwisle said. “We can tell by the soil condition and the look of the plant whether it needs an extra dose of water.”

But when things get dire, there must be tolerance for occasional bouts of brown grass and dying plants, as the authorities restrict watering. Last summer, about six million people faced restrictions on their use of water hoses in the northwest parts of England, said Trevor Bishop, the head of water resources at the British Environment Agency.

“Garden water can be considerable,” Mr. Bishop said. “Using a hose pipe for one hour uses as much water as a family of four over a whole weekend.”

Such measures have not been implemented so far this year and may not be deemed necessary unless the drought continues through the winter and into next summer, Mr. Bishop said.

However, watering is banned in parts of France, given the current drought. And much of Texas is under increasingly strict restrictions on how many days sprinkler systems can be used.