Easiest perennial with long blooming time? Your favorite and why?

I have water restrictions again this summer. Mid atlantic region with fair amount of clay. My black eyed susans and yarrow do excellently, but some others are very high maintenance and hard to grow. If you can't water them a lot, lots of sun, what is really hardy with long flowering season? I'm hoping for reds, pinks, purples (most of my stuff is yellow now)...Easiest perennial with long blooming time? Your favorite and why?
I love chocolate cosmos (cosmos atrosanguineum)! they are a true perennial hardy to zone 7. The reasons why I love them are: a very unusual rich brownish red flower color, the bloom from July through first frost, they tolerate poor soil and will do ok with limited water once they are established, ohhhhhh and they smell like chocolate!!!!!





http://www.clematis-nursery.co.uk/Cosmos鈥?/a>





http://www.cottage-gardens.net/showdetai鈥?/a>





One of my other favorites for a color other than yellow, that is drought tolerant, has a long bloom time is is a fun dark red color. It is Gaillardia grandiflora ';burgundy.'; It too makes a good cut flower.





http://www.parkseed.com/product_images/4鈥?/a>





However, since your watering is limited, I think that it would be money better spent if you wait until fall to plant so that there would be less of a chance of losing them. But, it definitely could be done if you really wanted them for this summer. I have plenty of other ideas if you need more!Easiest perennial with long blooming time? Your favorite and why?
For pinks, yellows, oranges, and whites consider the coneflowers:





http://springhillnursery.com/search.asp?鈥?/a>





If it's purple you're seeking the minty smell of salvia may be one to consider also:





http://springhillnursery.com/product.asp鈥?/a>





And for crimson, try Scabiosa (also in pink and/or blue):





http://springhillnursery.com/product.asp鈥?/a>





All of these are my favorites simply because they are quite hardy and drought resistant.





Also ... to help with your clay soil ... when you plant, use a peat humus and mix in with your soil at planting time. It will help to enrich your soil and provide nutrients to the plant roots at the same time. (http://www.gardening-quick-n-easy.com/so鈥?/a>





ENJOY!!
these are shrubs but they're my favorite! Rose of Sharons stand up to heat and need very little water.... and have flowers all summer long. I got the new one for this year.... ';lil kim'; ....which will only get 3 feet tall and the flowers last longer then a regular rose of sharon!
Yellow daylilies are very hearty and multiply every year. They bloom from late may til august in Illinois and do not require much watering. Bee balm, coneflower and stonecrop are also very nice with a long flowering season. Stonecrop is even good in draughts.All of these grow to about 2-3 ft high with multple blooms. Coneflowers are very similar to black-eyed susans but have white or purple flowers. Stonecrop is usually pink and bee balm can be light pink to dark magenta.

Ltd