Preparing Your Hive for Winter: The Fall Checklist

---

title: "Preparing Your Hive for Winter: The Fall Checklist" category: "Seasonal Care" summary: "Winter colony losses are mostly caused by decisions made in August and September, not January. Here's the fall prep checklist that gives your bees the best chance of making it through." readTime: 8 difficulty: "beginner" season: "fall" slug: "fall-winter-prep" publishedAt: "2026-03-02" course: "beginner" module: "Seasonal Care" lessonOrder: 17

Most winter colony deaths have their root cause in September, not February. By the time a colony collapses in January, the decisions that led to it — untreated Varroa, inadequate stores, a failing queen — were made months earlier. Fall preparation is the highest-leverage work of the beekeeping year.

Here's the checklist, in the order it matters.

1. Treat Varroa — This Is Non-Negotiable

Your fall Varroa treatment is the most important intervention of the year. Here's why: the bees your colony raises in August and September are its winter bees. These long-lived bees (they can survive 4–6 months, compared to 4–6 weeks for summer workers) need to enter winter with intact fat bodies and healthy immune systems. A bee that developed in a cell infested by Varroa enters life already compromised — shorter-lived and immunologically weakened.

Timing: Treat before your colony raises its winter bees — in most of North America, this means treating in August. Waiting until September or October means the damage is already done.

Threshold: If your August alcohol wash shows 2% or higher (2 mites per 100 bees), treat immediately. Some beekeepers use a 1% threshold in fall given the higher stakes.

Treatment options in brood-present colonies: Apivar (amitraz strips), Apiguard (thymol gel), or MAQS (formic acid). Each has temperature requirements and timing considerations — follow label instructions.

Oxalic acid (brood-free treatment): Highly effective, but only when the colony has no capped brood (mites in capped cells are not exposed). In most climates, this means waiting until mid-to-late October or November when the colony has stopped or greatly reduced brood rearing. Oxalic acid dribble or vaporization in a brood-free colony reduces mite load by 95%+. It's an excellent insurance treatment after a primary fall treatment.

Do a mite wash 4–6 weeks after treatment to confirm efficacy. If counts are still elevated, reassess your treatment protocol.

2. Assess Winter Food Stores

A full-strength colony in a Langstroth deep needs 60–80 lbs of capped honey to survive winter — roughly 6–8 fully capped deep frames, or the equivalent in medium frames. This is a minimum in cold climates; more is always better.

How to estimate: Heft the back of the hive with both hands before cold sets in — a heavy hive (difficult to lift one side) is well-stocked. More precisely, pull frames and count capped honey frames. A full deep frame of capped honey weighs approximately 8–9 lbs; a full medium frame, approximately 6 lbs.

If stores are short: Feed 2:1 sugar syrup (2 parts sugar to 1 part water by weight) in early fall while temperatures are still above 50°F — bees need warmth to process and dehydrate the syrup, cap it, and store it. Stop syrup feeding when temperatures consistently drop below 50°F. Bees cannot properly process cold syrup, and uncapped liquid stores can ferment over winter.

Pollen substitute: Late summer and fall pollen is important for the fat body development of winter bees. If your area experiences a late-summer dearth (common in late July–August in many regions), a pollen substitute patty placed directly on the top bars can support fat body protein stores in the bees your colony is raising for winter.

3. Evaluate Your Queen

A colony going into winter needs a young, productive queen. A failing or aging queen may limp through summer but won't produce the population of healthy winter bees needed for spring buildup.

Signs of a queen problem in late summer:

• Brood pattern becomes irregular or spotty — many empty cells in the middle of brood frames
• Fewer frames of brood than in previous inspections without an obvious reason
• Supersedure cells appearing — the colony is already attempting to replace her

Requeening in late summer (July–August) is often the right call for colonies with queens in their second or third year, or colonies that show a struggling brood pattern. A young, well-mated queen heading into winter means strong spring buildup.

4. Reduce the Entrance

A full-width hive entrance in winter is an invitation for mice. Mice enter hives in fall searching for warm nesting sites, and will destroy comb and kill bees. An entrance reducer set to the smallest opening (typically 3/8") keeps mice out while still allowing adequate ventilation.

Install the entrance reducer before nighttime temperatures drop consistently into the 40s°F (below 10°C).

5. Ventilation and Moisture Management

Bees don't die from cold — they die from moisture. A winter cluster generates significant heat and water vapor from respiration. If that moisture condenses on cold surfaces above the cluster and drips down onto the bees, it chills and kills them.

Upper ventilation: Many beekeepers add a small upper entrance (a 3/8" notch in the inner cover, or a shim between boxes) to allow moist air to escape without creating a draft on the cluster. In humid climates, this is particularly important.

Quilt boxes or moisture quilts: A moisture quilt (a box filled with wood chips or burlap above the inner cover) absorbs condensation before it can drip. Useful in wet climates but not universally necessary.

Insulation: In cold climates (sustained below-zero temperatures), wrapping hives or adding an insulation board above the cluster reduces the energy the bees expend maintaining cluster temperature. The goal is not to heat the hive — bees do that themselves — but to reduce heat loss.

6. Leave Them Alone

Once the cluster forms in late fall, minimize inspections. Opening the hive in cold weather breaks the cluster, chills bees, and disrupts the thermal envelope the colony is maintaining. Resist the urge to check until temperatures reliably reach 50°F+ on a sunny day.

The exception: if you see concerning signs at the entrance in mid-winter — no dead bees being removed (normal in cold weather), a sudden large number of dead bees, or evidence of mouse activity — a quick external inspection is warranted.

Key Takeaways

• Treat Varroa in August, before your colony raises its winter bees. This is the highest-impact action of the year.
• Verify stores are 60–80 lbs of capped honey before cold sets in. Feed 2:1 syrup to make up any deficit while it's still warm enough.
• Evaluate your queen in late summer — a weak queen now means a weak spring.
• Install an entrance reducer before mice start looking for winter housing.
• Provide upper ventilation to manage moisture. Cold doesn't kill winter bees; wet cold does.
• Leave the cluster alone once winter sets in. Check externally; open the hive only when temperatures allow.