Winter Preparations: Reducing Risks for Your Bees

Winter preparation determines the success of the next season. A colony that goes into winter well-prepared starts spring with strength and energy. Poorly prepared colonies, on the other hand, weaken, starve, or die. Autumn is the last chance to get everything right. In this guide, you will learn step by step what you need to do from August to November so your bees survive the winter safely.

The Winter Preparation Calendar

Winter preparation spans several months. Here is your timeline:

Month	Task	Priority
Late July/August	Last harvest, start Varroa treatment	Very high
August	Begin feeding (parallel to treatment)	Very high
September	Complete feeding, assess colony strength	High
October	Queen check, unite weak colonies	High
November	Mouse guards, entrance reducers, storm protection	Medium
December/January	Oxalic acid residual mite treatment	High

Step 1: Varroa Treatment

Varroa treatment is the first and most important step of winter preparation. Without consistent treatment, damaged winter bees hatch that will not survive the winter.

Treatment Timeline

1. Late July/August: Main treatment with formic acid 60% (after the last harvest)
2. September: Monitor treatment success (natural mite drop below 1/day)
3. If needed: Follow-up treatment with formic acid
4. December/January: Residual mite treatment with oxalic acid during the broodless period

Step 2: Fall Feeding

After the honey harvest, the colonies have no food reserves. You must replace the extracted honey with sugar syrup. Fall feeding is the second most important measure of winter preparation.

How Much to Feed?

The right amount depends on the hive type and existing food reserves:

Rule of thumb: Per kilogram of winter food needed, you require 1 liter of sugar syrup (3:2 ratio) or 1.2 liters of ready-made inverted syrup.

Sugar Syrup or Inverted Sugar Syrup?

Feed Type	Mixture	Advantages	Disadvantages
Sugar syrup 3:2	3 kg sugar : 2 L water	Inexpensive, proven	Bees must invert it
Sugar syrup 2:1	2 kg sugar : 1 L water	Thick, rapid uptake	Harder to mix
Inverted syrup (commercial)	Ready solution	No work for bees	More expensive

Timing of Fall Feeding

Feed early and fast: Give larger portions (3 to 5 liters) at once rather than many small feedings. This way the summer bees build up the food reserves quickly, and the later winter bees don't have to process the feed.

Feeding Systems

1. 1

   Frame Feeder (Inside the Hive)

   A frame feeder (e.g., made of plastic) replaces an outer frame in the hive. The bees climb inside and take the feed directly. Capacity: 1.5 to 3 liters. Advantage: Rapid uptake, no drowning. Disadvantage: Frequent refilling.

2. 2

   Top Feeder (On the Hive)

   A shallow tray or bucket with a float is placed on top of the brood box (instead of the honey super). Capacity: 3 to 10 liters. Advantage: Large quantities at once. Disadvantage: Hive is open, robbing risk.

3. 3

   Feed Box

   A special box with an integrated feed trough, placed on top of the brood box. Capacity: 5 to 15 liters. Advantage: Large quantity, enclosed, no robbing. Disadvantage: Additional investment.

Step 3: Assessing Colony Strength

Not every colony deserves to be overwintered individually. Weak colonies cost feed, labor, and space -- and often don't survive the winter anyway.

Assessment in September

Uniting with the Newspaper Method

Uniting two weak colonies into one strong one is simple and effective:

1. The stronger colony stays in its location
2. Lay a sheet of newspaper on the top box (with a few pin pricks)
3. Place the weaker colony's box on top
4. The bees chew through the newspaper over 1 to 2 days -- during this time they get used to each other
5. The queen of the stronger colony prevails (or you pre-select the better queen)

Step 4: Queen Check

A queenless colony in winter is lost. Check in September one more time whether all colonies are queenright:

• Eggs or young larvae present? Then the queen is there.
• Only capped brood and no eggs? Observe closely -- possibly the queen has taken a laying break, or she is missing.
• Drone brood in worker cells (domed cappings on worker cells)? The colony is queenless and has laying workers. Dissolve or unite with a queenright colony.

Step 5: Winterizing the Hive

From October, you prepare the hives for winter:

Mouse Guards

Mice seek warm quarters in autumn -- and a beehive offers everything they need: warmth, protection, and food. A mouse in the beehive eats combs, disturbs the winter cluster, and contaminates the hive with droppings and urine.

Mouse guard: A metal grid (8 mm mesh) across the entrance. Important: The mesh must be large enough for bees to pass through (a bee needs 8 mm) but small enough to keep mice out. Commercial mouse guards cost less than 2 euros per colony.

Insulation: Yes or No?

The question of insulation is debated among beekeepers:

Method	Advantage	Disadvantage
No insulation (wooden hive)	Good ventilation, no mold	Higher food consumption
Polystyrene hive (Segeberger)	Natural insulation	Can trap moisture
Additional insulation (bubble wrap)	Less food consumption	Risk of condensation
Skep/straw hive	Excellent insulation	Uneconomical for many colonies

Recommendation: Uninsulated wooden hives can work well in Germany when colony condition, stores, Varroa pressure, weather protection and moisture control are all suitable. Polystyrene hives can affect feed consumption. Extra insulation is often unnecessary in normal winters and can promote condensation when fitted poorly.

Step 6: Residual Mite Treatment in Winter

The last measure of winter preparation paradoxically takes place in the middle of winter: the oxalic acid treatment during the broodless period.

The Right Timing

• When: 3 to 4 weeks after the first hard frost (typically mid-December to early January)
• Condition: The colony must be broodless (no capped brood)
• Temperature: Below 5 degrees Celsius, bees are in the winter cluster

Application (Trickling Method)

1. Prepare oxalic acid dihydrate solution 3.5% in sugar syrup (or use a ready-made preparation)
2. Briefly open the hive, remove the inner cover
3. Trickle 5 ml per occupied seam directly onto the bees
4. Maximum: 50 ml per colony
5. Close the hive immediately
6. Apply only once per winter (repeated treatment damages the bees)

Avoiding the Most Common Causes of Winter Loss

Conclusion: Winter Preparation as an Investment

Winter preparation is not a tedious chore but an investment in the next season. Those who work carefully in autumn have strong, healthy colonies in spring that start the season quickly. The key points summarized once more:

1. Treat Varroa consistently -- the single most important factor
2. Feed sufficiently -- better too much than too little (15-20 kg)
3. Assess colony strength -- unite weak colonies
4. Queen check -- don't overwinter queenless colonies
5. Winterize the hive -- mouse guard, entrance reducer, storm protection
6. Oxalic acid in winter -- the final measure in the Varroa program

The art of overwintering is not an art -- it is consistent craftsmanship. Those who master the basics lose fewer than 5 percent of their colonies.

Start planning your winter preparation now. Your bees will thank you next spring -- with a powerful start to the season and a good harvest.

Read also: Fall Feeding - Amount, Timing, and the Right Method In December: Winter Treatment with Oxalic Acid - The Residual Mite Treatment What comes next: Bees in Winter - How Your Colonies Survive the Cold Season