If they are container grown, you can plant anytime. If bare-root, you can plant now, as long as they have time to settle in and start new growth before the really hot weather sets in. I moved a bunch last April and May, and they did just fine. If you are planning to order from out of state, the grower may not ship to Texas until the fall.
Jim

I planted daylilies in April and October last year. Some of the ones planted in April bloomed in May and June.

Thanks!

When I use to order dayliles from Patron's I got them in January, they always did better than the dayliles I received later in the year. They had time to get a good root system going before the hot weather set in. Barbra

If you're in the Dallas area, Saturday, April 21, would be a great time to plant because that's when the Daylily Growers of Dallas will hold their spring plant sale at NorthHaven Gardens. I've always been happy with what I get there, and mostly they bloom that same summer. Nice folks to deal with also. But be there early!