Yes indeedy. They'll do much better for you that way. You'll notice the difference real soon too.
Edit: Forgot to ask.. you do have a sand or gravel substrate, right? If you're already using a soil-type planted tank substrate, like eco-complete or some of the others... those have nutrients and you wouldn't need root tabs in addition to that. (Unless it's like 3+ years old and the nutrients have depleted.)