How I Raise Nucs (My Proven, Step‑by‑Step Method)

Petr Drabek
Nov 3
6 min read

A practical guide to creating strong, healthy nucleus colonies for growth, queen replacement, and winter insurance.

Why I raise nucs

Over the years, raising nucleus colonies (“nucs”) has become one of the highest‑leverage habits in my beekeeping. Nucs let me:

Replace failing queens on my terms.
Expand apiary numbers without buying packages.
Keep a “spare tire” for winter losses.
Select genetics that thrive in my climate and management style.

My goal is simple: build compact, well‑fed, mite‑managed nucs with young queens that are ready to either grow into full hives or overwinter as reliable backups.

Timing and targets

I make most nucs as soon as drones are flying and mature (for queen mating), when nectar is available or I’m ready to feed. In my area this typically means late spring into early summer; adjust to your local flow and weather. I want each nuc to reach these benchmarks:

2–3 frames of solid brood within 4–6 weeks (if headed by a mated queen).
Adequate food: at least one heavy food frame (honey/pollen) plus steady feed until self‑sufficient.
Low mite load confirmed by sampling (sugar/CO₂ roll or sticky board) and treated if needed according to local regulations and label instructions.

Equipment I actually use

5‑frame nuc boxes (wood or poly). Ventilated lids help during transport.
Entrance reducers/screened entrances to prevent robbing.
Internal feeders (frame or top feeders) for 1:1 syrup.
Extra drawn comb if available (huge advantage); otherwise foundation.
Queen cages with candy plugs and push‑in cages for tricky introductions.
Queen cells (ripe), mated queens, or the materials for a walk‑away nuc.
A dedicated nuc record card or app notes per box.

Pro tip: Label every nuc clearly (number + queen source + date). Small details save big headaches later.

Donor colony selection (where I pull frames)

I only take from booming, disease‑free colonies with good temperaments and low mite counts. I prefer colonies that:

Wintered well and built up early.
Maintain solid, even brood patterns.
Show hygienic behavior and low swarming pressure.

I never build nucs from colonies showing chalkbrood, European foulbrood (EFB), American foulbrood (AFB), or noticeable viral symptoms. If in doubt, I test or skip the donor.

The nuc “recipe” I follow

I aim for a 5‑frame nuc configured like this:

Brood frame with eggs/young larvae (with adhering nurse bees)
Capped/emerging brood frame (with adhering bees)
Food frame (honey + pollen)
Drawn comb (for the queen to lay immediately)
Foundation (to expand)

Then I shake in extra young bees from a brood frame (avoid shaking the queen!). Young bees are more likely to stay; I try to bias the nuc with nurses. Not necessary if nuce is created early in spring.

Entrance: reduce to a small opening.
Location: shade or dappled light for the first days helps a small colony regulate temperature.
Feed: 1:1 syrup immediately unless a strong nectar flow is on.

Queen options (and how I decide)

Best acceptance and fastest build: introduce a mated queen in a cage.

Cost‑effective and still fast: add a ripe, protected queen cell (ready to emerge in ~1–2 days). Make sure the nuc is queenless.

Budget/backup option: make a walk‑away nuc with a frame of eggs/young larvae and let them raise their own queen. Slower timeline; results depend on weather and drone availability.

My introduction routine (mated queen)

Assemble nuc and ensure it’s queenless (no hidden virgin). If I split from a single donor, I wait at least 6–12 hours before introduction to increase acceptance.
Hang the caged queen between brood frames with candy plug accessible.
Do not disturb for 3–5 days. Then check for release and calm behavior around the queen.
First inspection (day 7–10): look for eggs laid in a solid pattern.

Using queen cells

I position a ripe queen cell near young brood, well protected from crushing.
I avoid jostling and temperature shock during transport.
I do not open the nuc until 10–14 days later, to avoid disrupting mating.

Timeline note (queens): From egg to emergence is ~16 days for queens; mating and the start of laying often occur one to two weeks after emergence, depending on weather and drones.

I always mark my queens after they are mated, it makes live easier.

Feeding strategy

Small colonies don’t have foragers to spare. I:

Feed 1:1 syrup in small internal feeders until I see steady white wax and nectar coming in.
Avoid open feeding near nucs (invites robbing).
Ensure pollen availability; if flows are poor, I provide a quality pollen substitute outside robbing hours and only if truly needed.

Robbing prevention and nuc security

Tiny entrance; widen only as the population grows.
Keep nucs grouped but spaced so drifting is limited.
Work quickly, keep boxes covered, and avoid spilling syrup.
If robbing starts, close entrances to a single bee‑width, add a wet towel over the lid temporarily, and stop feeding at the entrance.

Mite management (non‑negotiable)

I sample all nucs after they’re established and again before winter. If treatment is needed, I use methods and products legal in my country and follow all label instructions. Lower brood volumes can make nucs more responsive to timely treatments—this is where nucs shine.

My week‑by‑week checklist

Day 0: Build nuc, feed, add queen (caged) or cell. Reduce entrance.

Day 3–5: Confirm queen release (if caged). Don’t handle frames more than necessary.

Day 7–10: Look for eggs. Add another drawn frame if the queen is laying and bees are drawing comb.

Day 14–21: Expect small patches of capped brood from a mated queen; if using a cell, this may be the pre‑laying window.

Day 28–35: Should have a frame or two of brood; adjust feed. Consider moving to a 10‑frame box if population and nectar justify it.

If there’s no sign of a laying queen by day 28–35, I re‑queen immediately. Don’t let nucs drift into laying worker territory.

Scaling up queen production (how I do small runs)

When I want more queens:

I create a queenless starter to prime nurse bees (lots of open brood moved above an excluder or shaken into a dedicated box with food).
I graft (or use the Miller method) and return cells to a finisher with heavy nurse populations and open nectar.
I protect ripe queen cells and distribute them to nucs on the day before emergence.

For beginners, buying a few quality mated queens to seed nucs is absolutely fine and often the most reliable path.

When to promote a nuc to a full hive

I upsize when:

Bees cover all five frames and need room.
The queen has a solid pattern and fresh eggs across multiple frames.
There’s a nectar flow or I’m committed to feeding.

I move the nuc into a 10‑frame box with additional drawn comb/foundation and continue careful feeding and mite monitoring.

Overwintering nucs (my recipe)

Overwintering nucs is like carrying spare queens through winter. I aim for:

Population: a dense cluster filling a 5‑frame box (or better, a double‑nuc setup: two five‑framers sharing warmth, separated by a divider in a single 10‑frame body or stacked 5‑over‑5).
Stores: at least 2–3 full deep frames of honey (adjust for your climate). I top up with syrup early and use fondant/candy only as insurance in late winter.
Insulation & ventilation: insulated lids, moisture control, and small upper ventilation if condensation is an issue in your area.
Varroa: confirm low mite counts after autumn treatment and again in the brood‑light window. I always use extended release oxalic acid.

Come spring, these nucs explode and give me options—combine, sell, or use to re‑queen laggards.

Records I keep (and why it matters)

Every nuc gets:

Build date and source colony.
Queen source (mated/cell/walk‑away) and genetics.
Inspection dates with brood pattern notes.
Feed amounts and mite counts.

Good records turn nuc‑raising from guesswork into a repeatable system. I use our app mobile app ApiNote for all that work.

Troubleshooting quick list

No eggs by day 28–35: re‑queen.
Spotty brood early: young queen settling or poor mating; reassess in a week.
Robbing: shrink entrance, pause feeding, work early/late in day.
Chilled brood (spring cold snap): improve insulation, reduce space, avoid long inspections.
Laying workers: add a frame of open brood weekly for 2–3 weeks or combine with a queenright nuc.

Safety and biosecurity

Disinfect tools, especially between apiaries.
Quarantine suspicious colonies; don’t donate from them.
Learn to recognize AFB/EFB; if suspected, consult local experts immediately.

Final thought

Raising nucs isn’t complicated—it’s disciplined. Build with healthy brood and young bees, give them the right queen at the right time, feed steadily, prevent robbing, and manage mites. Do those consistently, and nucs will become your most reliable engine for growth and resilience.