September: The Most Critical Beekeeping Month
September is the single most consequential month in beekeeping. The bees raised in August through September are your winter bees — they live 4–6 months versus the 6-week summer lifespan. If varroa damaged these bees, they die early and the cluster fails mid-winter.
This is your final effective treatment window before winter bees are raised. Delaying treatment into October means the damage is already done to the bees that must survive until March.
All supers should be off by September 15 in northern states. Any remaining honey in supers will crystallize or be consumed by the colony. Remove them to reduce hive volume and consolidate the cluster.
The hive should feel very heavy. Target 60–80 lbs of honey in the brood box. A light hive needs immediate feeding — winter bees cannot be raised on empty comb.
Feed 2:1 sugar syrup until bees stop taking it. They self-regulate intake once stores are adequate. Do not stop until the hive feels heavy or the bees reject the feeder.
No laying queen in September means the colony will not survive winter. Look for eggs and young larvae. If the queen is failing, requeen immediately or combine with a stronger colony.
💡 Tip: September varroa treatment is the single most important fall task. Even perfect winterizing cannot save a varroa-damaged winter bee population.
October: Winterizing Checklist
October is the physical preparation month — closing up the hive structure for cold. Focus on reducing drafts, blocking pests, managing moisture, and securing the hive against wind and weight.
Limits cold drafts and deters mice from entering. A reduced entrance also makes it easier for guard bees to defend against robbers during the fall nectar dearth.
Mice enter in October to nest through winter. A simple metal mesh mouse guard blocks them while allowing bees to pass. Install before the first frost.
Screened bottom boards are great in summer but increase cold airflow from below in winter. Insert the solid tray to reduce drafts while maintaining some ventilation.
Drill a 3/4" hole in the upper box or prop the inner cover 1/4". Moisture from the winter cluster must escape upward. Without it, condensation forms on the inner cover and drips onto the cluster, chilling bees.
A 1–2 inch rigid foam insulation board cut to fit the inner cover provides thermal protection without blocking ventilation. Do not seal the hive completely — bees still need fresh air.
Secure with ratchet straps in wind-exposed locations. A tipped hive in January is a dead hive — the cluster breaks and bees freeze individually.
Reduces wind chill and absorbs solar heat during short winter days. Wrap the hive body only, not the entrance or upper vent hole.
Metal Entrance Mouse Guard
Fall Feeding: The 2:1 Syrup Guide
Feed 2:1 sugar syrup from September through mid-October while temperatures stay above 50°F. Bees cannot process syrup below 50°F, so switch to dry sugar or fondant before cold weather arrives.
Fall feeding is different from spring feeding. In spring, thin 1:1 syrup mimics nectar and stimulates brood rearing. In fall, thick 2:1 syrup is stored directly as winter food. The higher sugar concentration requires less evaporation, making it efficient for bees to cap and store.
Ratio
2 parts white sugar : 1 part water by weight. Thicker = more efficient to store, less energy to convert.
Temperature
Feed only while daytime temps stay above 50°F. Cold bees cannot evaporate moisture from syrup.
Amount
Feed until bees stop taking the syrup. When stores are adequate they self-regulate and ignore the feeder.
If temperatures drop before stores are adequate, switch to dry sugar using the mountain camp method — pour 5 lbs of white granulated sugar directly on newspaper placed on the top bars. The bees cluster directly below and consume the sugar as needed. Alternatively, place a fondant candy board on the inner cover for a more organized emergency feed.
⚠️ Warning: Stop liquid syrup once nighttime temperatures consistently drop below 50°F. Cold bees cannot evaporate moisture from syrup — it accumulates in the hive causing dysentery.
How Much Food Does a Colony Need to Overwinter?
A colony needs 60–80 lbs of honey stores for a moderate winter. Cold climates require 80–100 lbs or more. The single most common preventable cause of winter death is starvation — not cold.
| Climate | Minimum Stores | Recommended |
|---|---|---|
| Mild — South, Pacific Coast | 40–50 lbs | Short winter, brief cluster period |
| Moderate — Mid-Atlantic, Midwest | 60–80 lbs | Standard recommendation |
| Cold — Upper Midwest, Northeast | 80–100 lbs | Long winter, extended cluster |
| Very cold — Canada border, high altitude | 100+ lbs | Add candy board backup |
How to estimate honey weight: A full deep frame of capped honey weighs approximately 6–8 lbs. A full medium frame weighs 4–5 lbs. Count your capped frames and multiply. If your brood box has 8–10 frames of honey, you are in good shape. If it has 4 or fewer, feed aggressively.
Final Inspection Before Winter
Your last inspection in late October or early November confirms the colony is queenright, well-fed, and structurally ready for months of isolation. Work quickly — this visit should take under 5 minutes to minimize chilling.
Look for eggs and young larvae. A queen laying in late October is producing the long-lived bees that will carry the colony through to spring. No eggs = a critical problem to solve immediately.
Any queen cells in late October indicate a queen problem — either the colony is trying to supersede or swarm on a reduced scale. Solve immediately or combine with a strong colony.
Stores should flank the brood nest, not be isolated away from the cluster path. The cluster moves upward and outward through winter. Honey above and beside the brood is accessible; honey in a separate box is not.
Empty syrup feeders, entrance feeders, and frame feeders before winter. They create unnecessary space, collect condensation, and can leak if they freeze and thaw.
Colony strength, honey estimate, queen confirmed, treatments applied, date closed. This record is your baseline for the first spring inspection.
Frequently Asked Questions
When daytime temperatures consistently drop below 50°F. Opening in cold weather chills brood, breaks propolis seals, and depletes winter cluster bee lives that cannot be replaced.
In USDA zones 5 and below — yes, black tar paper wrap is standard practice. In zones 6 and above it is rarely necessary. Ask your local club what they recommend for your specific microclimate.
If temperatures drop below 50°F before your colony has adequate stores, switch from liquid syrup to dry sugar (mountain camp method) or fondant candy boards. Liquid syrup causes dysentery in cold bees.
September is your last effective treatment window. By October, winter bees have already been raised and any mite damage is done. Treat in September, not October.