As an Amesbury Rotary service member, Cheryl Keim has worked on establishing tough, drought-resistant flowering perennials at the Rotary Adopt-a-Spot triangle garden at the intersection of routes 110 and 150 in Amesbury.  The first year new plants need extra water until their roots grow deep enough to help them endure heat and drought.  With a good start, they will thrive and provide a reliable show of color every year.
She has watered the young garden plants every 2 to 4 days, and they have survived despite the drought, blooming well and looking like they will survive and prosper.  
She worked carefully using a small bucket to dispense the water to all of the plants, stepping lightly, careful not to compress the roots making sure the gaillardia and echinacea plants (they look like colorful daisies) get a good drink; they are the newest additions and are blooming vigorously.  The 20 gallons every few days seems to be just enough to keep everything going until rains return. Here are some photos of the garden!