I live in southern middle Tennessee. Our summers can be very hot and dry. My backyard is fenced and it runs along a fairly large treeline. It seems the trees take in all of the water for 10-15 ft into the yard. A flower bed runs (approx 5 x 40 ft) along the fence and it does well until June when the entire bed just dries up. I have wanted the bed to attract butterflies, hummingbirds, and birds. What are some solutions to overcome the lack of moisture? Should I change plants, add dirt, or just water more?
You could plant drought tolerant plants or add a soaker hose to the bed to aid in watering and cover this with mulch to help retain the moisture. his article may also help: https://www.gardeningknowhow.com/special/xeriscape/irrigation-systems-for-xeriscape-environments.htm
For a list of drought tolerant plants, these articles should help: https://www.gardeningknowhow.com/special/xeriscape/drought-tolerant-flowers.htm