The wilting could just be a reaction to the planting - transplant stress - combined with the forgotten watering. Keep watering them deeply (perhaps not daily - just do not allow them to dry out) and give them some time to recover. My dichroa is in a container and has now and again shown signs of drought wilting, but has responded to increased watering well.

Are there only 2 fert spikes for the entire bed or 2 per plant? 2 per plant is probably excessive. FWIW, fertilizer spikes are the least efficient method of fertilization. As a matter of fact, they are pretty much a waste of money and I'd avoid using them at all. If necessary, a granular type fertilizer scratched into the soil surface over the entire area will provide much better results (and save money) but newly planted plants seldom require additional fertilizer. A good organic mulch should suffice for 99% of your nutrient requirements if your soil is any good at all.