Answer: Soil might contribute to the problem, but establishment is more likely the problem. Even though your drought tolerant plants are heat lovers, they need to establish a deep root system in order to thrive under hot, dry situations. So, it's important to water deeply the first year so the roots can establish themselves. Plan on deeply soaking your plants once each week for the remainder of the growing season. By next spring they should be mature enough to endure the hot summer sunshine with only occasional waterings.
Best wishes with your garden!
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