Add the second box when the bees have drawn and are actively working about seven of the ten frames in the first one. Not when seven frames have comb on them — when seven frames are covered in bees and being used. That distinction is where most people get it wrong in both directions.
Why not add it earlier?
Because a northern spring is cold, and a colony can only heat so much space. Give a small colony two boxes in May and it spreads thin, struggles to hold temperature in the brood nest, and slows down.
This is one of the places where advice written for warmer climates actively hurts you here. In Georgia, extra space early is harmless. In North Dakota in May, it costs you buildup.
What happens if I wait too long?
They run out of room, and a colony out of room starts thinking about swarming. Once swarm preparations begin, adding space often doesn't stop them — you've missed the window.
Congestion also caps the laying rate. A queen with nowhere to lay simply lays less, and in a short season that's growth you never get back.
How do I judge "seven frames working"?
Open the box and look down between the frames without pulling them. If bees cover the top bars across seven or more frames and you can see comb drawn and in use beneath, it's time.
Pull one or two frames to confirm brood is present out toward frames three and eight. Brood spreading outward is the real signal — the queen is running out of middle.
Where should the new box go?
On top, in almost every case. Bees expand upward naturally and it keeps the brood nest intact.
You'll sometimes read about "checkerboarding" or moving drawn frames up to encourage them. It works, but it also breaks up the brood nest, and in a cool northern spring that's a real cost. For a first- or second-year beekeeper, just add the box on top.
Should I feed after adding?
Yes, if they're still drawing comb. Drawing wax is expensive — bees consume a lot of resources to produce it — and a colony drawing a full box of foundation with no flow on will stall without feed.
Stop feeding once a real flow starts, or you'll end up with syrup stored where you wanted honey.
What about a third box?
Same rule. Seven frames working in the second box before the third goes on. Most first-year colonies in our territory get to two deeps; a strong one on a good flow might justify a third or a super.
Questions about any of this? Call or text us at (701) 809-0153. We're always happy to help, even if you didn't get your bees from us.