You understand the three pillars of successful overwintering: colony health, winter food stores, and hive environment. But when do you actually do each task? This article provides a month-by-month timeline showing exactly when to assess, when to intervene, and when it’s too late.
Winter preparation isn’t a single event—it’s a series of timed steps that ensure the bees entering winter are healthy, well-fed, and protected.
Three Phases of Fall Preparation
- Early Fall (August in most regions): Assessment and varroa treatment. Determine what each colony needs and reduce mite populations before winter bees are created.
- Mid-Fall (September in most regions): Feeding and adjustments. Supplement food stores if needed, combine weak colonies, begin moisture management setup.
- Late Fall (October in most regions): Final preparation and weatherproofing. Install physical protection, complete moisture management, final checks before winter.
*Timing varies by region—northern beekeepers start several weeks earlier than southern ones.
Northern beekeepers compress these phases (July-September); southern beekeepers extend them (August-November). The principle remains constant: assess early, treat for varroa at the right moment, feed while processing is possible, weatherproof before hard cold arrives.
August (Northern) / September (Most Regions)
Although regionally specific, many beekeepers in the US consider this the most critical month. Miss this window and the risks to your colonies increase significantly.
Key tasks:
- Assess colony populations: Evaluate the size of the colony – current population – counting FOB (frames of bees), future population (assessing amounts of brood), and queen status. Strong colonies (8-10+ frames depending on region) are good overwintering candidates. Weak colonies (fewer than 5-6 frames) may need combining.
- Evaluate food stores: Use heft test and frame inspection. Know each colony’s status to plan feeding.
- Monitor varroa early (July): Use an alcohol wash or sugar roll and aim for ≤1% infestation (3 mites or fewer per 300 sample bees). Completing treatments by mid-August helps protect the generation of winter bees.
- Treat for varroa: Non-negotiable timing. Treatment must happen before winter bees emerge. Winter bees develop in late summer, and if they’re parasitized by mites, their fat body reserves are compromised—shortening their lifespan. See “Fall Varroa Management: Why Timing is Everything” for details.
- Stop splits: Colony-building season is over. Focus on strengthening existing colonies.
- Assess queen viability: Check brood pattern and queen performance—this is the last chance to requeen or combine colonies before winter, ensuring the colony can build strong spring populations.
- Gather moisture management materials: Start planning your approach. Assess colony size and hive setup. Plan for overwintering hive setup to control moisture.
September (Northern) / October (Most Regions)
Varroa treatment should be complete. Focus shifts to food stores and final adjustments.
Key tasks:
- Complete final inspections: Last chance for thorough frame-by-frame examination. Check queen status, brood pattern, store positioning, equipment condition.
- Feed if necessary: Use 2:1 sugar syrup. Feed heavily and quickly—provide large volumes (20-40 lbs if needed) before cold prevents processing. Stop feeding when temperatures drop consistently below 50°F. Avoid open feeding this late in the season—it encourages robbing and may not ensure equal access across colonies.
- Reduce entrances: Install entrance reducers sized appropriately for colony strength.
- Combine weak colonies: If you decide combining weak hives is justified, use the newspaper method or preferred technique. Two weak colonies combined have better survival odds than two separate weak colonies.
- Install moisture management: Place moisture boards, quilt boxes, or chosen system.
October (Northern) / November (Most Regions)
Window for major interventions is closed. Focus on physical protection and final checks.
Key tasks:
- Install mouse guards: Before mice seek shelter (typically as temperatures approach freezing). Verify snug fit that allows bees but blocks rodents.
- Add insulation or wraps: Based on regional climate and How do you protect your hive from winter weather? guidance. Ensure weatherproofing maintains moisture ventilation.
- Install wind breaks: Position hay bales, snow fence, or barriers if hives face significant wind exposure.
- Verify hive integrity: Check boxes stack properly, covers are secure, entrance reducers and mouse guards properly installed, no unwanted gaps or cracks. Painter’s tape is an easy fix to any gaps in the hive.
- Tilt hives forward: Small shim under back creates drainage slope toward entrance. A one-inch lift under the back of the bottom board is enough to direct condensation and rainwater forward. Having a small tilt year-round prevents moisture/rain from sitting on the bottom board.
- Final heft test: Confirm adequate weight. If concerningly light, only option is candy boards or fondant (Beekeepers are divided on which is the better option. Some say that fondant is easier to uptake due to moisture content – consider your variables and choose which will work best for your bees).
- Take notes: Record colony status, interventions performed, treatment methods, store levels. Invaluable for spring analysis.
Regional Timing Adjustments
- Northern climates (zones 3-5): Compress timeline by 4-6 weeks. “August” tasks in mid-July, “October” tasks in early September. Work quickly—your window is shorter.
- Southern climates (zones 8-9): Extend timeline by 4-6 weeks. “August” tasks in September, “October” tasks into November. Varroa treatment timing critical—treat before winter bee emergence (In warm climates, winter bees emerge later in the season, so delay treatment slightly—but still treat before you see the brood nest shrinking.).
- Coastal/mild climates: Monitor actual temperatures and bee activity rather than calendar. Flexibility matters more than rigid scheduling.
- High elevation: Expect earlier preparation but watch for temperature variability. Time varroa treatment and feeding for appropriate weather windows.
Avoid Common Late-Season Mistakes
What to Avoid
- Opening hives repeatedly: Once late fall arrives, stop routine inspections. Opening breaks propolis seals and disrupts cluster formation. Use painter’s tape to fix broken seals if needed.
- Late syrup feeding: Syrup fed when bees can’t process it (below 50°F) creates moisture problems. Switch to candy boards or fondant.
- Last-minute requeening: October requeening can be futile but a failing queen will definitely end in colony collapse. Make sure your colony is queen right – that may mean late requeening or combining colonies. No action will likely doom the colony.
- Late varroa treatment: October treatment (most regions) means winter bees already emerged with mite damage. Critical damage is done.
- Over-manipulating weak colonies: Weak colonies in October are simply weak. If combining is justified, do so—or accept potential loss.
When It’s Too Late
- Liquid syrup feeding: When temperatures consistently stay below 50°F and bees aren’t flying. Alternative: candy boards or fondant.
- Warm-requiring treatments: Many varroa treatments need 60°F+. Once cold settles, options become limited.
- Combining colonies: Once clusters form and temperatures prevent flight, combining is high-risk. If you decide combining is appropriate, late September/early October is typically the last window in most regions.
- Major equipment changes: Don’t switch bottom boards or add boxes once cold arrives. Disruption creates more problems than benefits.
- Full inspections: Switch to external monitoring once consistent cold and clusters form.
The Bottom Line
Fall preparation rewards early action. Assess in early August (or appropriate timing for your region), treat for varroa promptly, feed while temperatures allow, weatherproof before hard cold arrives. Act decisively when each window opens—your colony’s survival depends on timing.
