Sedum, probably 'Autumn Joy'

I agree with saypoint. You don't need to do anything with them, except enjoy them. They will gradually increase through the years, and eventually you will be able to divide them. Many people leave the stalk with the dead flowers for winter interest (I've found that a really harsh ice storm will knock them flat). Very early next spring, gently remove any remaining dead growth, and that's it! Well - if you have no rain for a couple months, they would like a drink of water, but sedums do very well in dry conditions and actually prefer to grow on well-drained slopes. Because these sedums are often late to sprout and don't look like much until fall, you may like to plant annuals for spring and summer pleasure. A short dianthus such as 'Spotty' would do well in that location, as would marigolds.

I mix daylilies and spring bulbs along with my sedum for a year around affect but not too close together.