Feeding in Summer?

I checked my colonies 3-4 weeks ago and they were doing great! Honey available in the younger (swarm) hives and the older hives were busting at the seams. Waiting for honey to cure and figured, "...give it a week and they'll have the honey cured and ready...", checked one hive last week for brood and stores for a trap-out and there was no open brood at all. Started a light 1:2 sugar:water to try and stimulate brood and surprisingly it worked, eggs and ready to go. Went in today and found no eggs no open brood no stores. Went to next hive and lifted...light as air. The other two hives ('russian') I'm getting into tomorrow (I am very slow at getting around) and this should tell me something as they always have extra honey when everyone else is feeding, I have watched them fly in directions other than where the other yards are. Point is, that I have two hives (not seen any robbing and they are in great moods) out of stores and three other hives bringing in stores. All colonies are bringing in pollen (yellow, golden, and almost orange). All have large populations. So I guess I'll start feeding them now and see what happens. I am not normally a feeder, until January to start brood stimulation, but I want to see what happens and if this is just their bloodlines. Elderberry is still blooming as are blackeyed susans and coneflowers, mint, some crepe myrtles and melons/cucumbers and other garden plants, with rose of sharon, acaisia and mimosa. Should these be enough nectar sources for them? There are alot of blooms within a mile, you can't look anywhere without seeing color.

I posted this because most folks with more experience are on crop pollenation and don't seem to rely on what's available like those of us here in town. Sorry I got long winded.