Answer: This depends partly on what kind of verbena you planted, many are annuals. The perennial types such as "Homestead" are marginally hardy in your area and tend to die back almost completely in the winter then come into regrowth very late in the spring. With a very well drained spot you would normally have a good chance of it surviving but this past spring was very stressful with crazy oscillating temperatures so you may well have lost it. You could trim it back, beginnning at the tips, until you reach live wood with some green inside the stem. So, yes it is slow but yes, too, it might be dead.
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