I planted a row of 28 Daylilies, 3 feet apart, in 2012, and many of the plants foliage touch each other. Many of these have become very large clumps in only three years, Daylilies really are hardy, fast growing plants, I agree with those who say choose by how often you wish to divide. I divided several large ones this year, and Frillylily is right about it being tough work. Good luck with your new bed :-)
Gale
