You need to deadhead verbena.....and celosia too. Really no need to feed if you have added compost to your soil....but you have to cut the old flowers off any annual to keep it blooming.
Linda C

Linda C,
Thanks. I really didn't see any dead flowers; it's just as if they disappeared. I see green bud clusters on the plants, and you would think that these will eventually bloom. I'll experiment by pulling one or two and see what happens.

I grow Verbina alot and I use 20-20-20 or 10-60-10 every 2 weeks I find they get lots of flowers and hardy I grow mine in pots and flowerbeds I love them I have all kinds of colors I buy the mixed I love the white eye it really beautiful Anna

I've been finding that the trailing varieties of verbena seem to perform MUCH better than the non-trailing type. I've got both types growing right now -- the non-trailing type is standing bolt upright, lanky and flowerless already, and the trailing verbena is lush and flowering, and beginning to spill out over the edge of a planter.

I agree about the trailing verbena being superior to the standard bedding varieties. My favorite bedding variety verbena is verbena rigida. I rarely see it available as plants but seed is easy to come by. I use it in hot dry poor soil areas that get some dog traffic. It doesn't miss a beat and just blooms and blooms.