I bought 4 Hibiscus bushes from Walmart last year and planted in the fall. They did great. Now I don't see any sign of life or new growth. Should these be showing signs of new growth???? Should I prune back?
I'm a solid 6a here & I don't usually see any sign of the hardy ones that die back to the soil until early June.
If you planted Hibiscus rosa-sinensis outdoors, then they are surely dead. This is a tropical species that is not hardy in zone 7.
If you bought H. moscheutos (or one of its hybrids like 'Lord Baltimore') that's another story entirely. This species is a hardy perennial, but they die to the ground and as tapla said, they don't show signs of life until well into spring, after most other perennials are up and growing (late April here).
The fact that you bought these plants at WalMart, tells me that you likely got Rose of Sharon's which are plenty hardy for your area. WalMart would never bring in a plant with such a narrow growing zone. I've seen numerous times on plant stakes or labels "Rose of Sharon - rosa sinensis" at big box stores, smaller hardware/nursery centers and other small garden centers. You would think that labeling would be correct but I would never depend on them being correct. I still take my Sunset Garden Book to the garden center to verify a plant will survive in my zone and/or any specific needs.
I'm sure I have the same plant as your 4. My plant loses its leaves over winter. I cut back all the thin branches back to the main stems in Spring. My plant is just beginning to develop leaves. Our weather has been in the 50 - 60's by day and nights are high 30's - 40's. We have had a few days in the 70's but not constant. I'd trim back the spindly branches now but until your soil gets to be around 60 degrees, you won't see much growth. A good garden book for your area would be very helpful to you even if you are not a big time gardener. It's very convenient to be able to run inside to get your book when you come across a weed, a pest, or your plant looks sickly.
I bet you'll have gorgeous flowers within a couple of months.