In this part of the country you can probably expect to see your bees drawing out comb spring through the first half of summer. Once late summer and fall arrives it seems nearly impossible to get them to draw out any new comb. They will just fill all empty available comb and not waste any resources on building new comb as they prepare for winter.
You want to encourage them to continue to draw as much comb as possible right now and into early summer. Feeding now will help them out tremendously until you get into a good nectar flow and then you will likely see them begin to ignore the syrup. Use your best judgment, but you can probably back off feeding once you get into the flow.
Heading into the dry part of the summer you may want to think about feeding again to help them through it, if necessary.
These are just a few observations I've made locally.
To everything there is a season....