BeezKnees

A Year in the Apiary - September Beekeeping Tasks (UK)

September overview – shifting from late summer to winter mode

September is a key month in the UK beekeeping calendar. The main summer nectar flow is usually over, evenings are getting cooler and your colonies are starting to slow down. The focus now is on making sure each hive has a healthy population, a sound queen and enough food to reach spring.

Much of the groundwork for winter was started in August. In September you are finishing varroa treatments, building up winter stores, combining weak colonies and weatherproofing the apiary. This is also the time to fit mouse guards and finish reducing entrances so your bees can defend themselves against wasps and robbing bees.

If you follow the full Year in the Apiary, September marks the point where you transition from active summer management to careful monitoring and preparation for winter.

Honey harvest and checking winter stores

If you did not harvest in August, September is often your last chance to take honey from many parts of the UK. Check your supers for fully or mostly capped frames. Harvest any genuine surplus, but keep in mind that your bees must go into winter with enough food of their own.

As a guide, a full-sized colony in the UK usually needs around 20–25 kg of stores to overwinter successfully. Some beekeepers quote slightly lower figures, but aiming at the upper end provides a safety margin in cold or prolonged wet weather.

Once you have finished extracting:

  • Return wet supers for a couple of days so the bees can clean out remaining honey.
  • Remove cleaned supers and store them securely to prevent wax moth and other pests.
  • Make a note of how heavy each hive feels when hefted – this will help you track food levels as autumn progresses.

Feeding bees in September

By September, most colonies are no longer bringing in large amounts of nectar, but they are still consuming food. Many UK beekeepers find that this is the main month for topping up winter stores.

If a hive feels light when you heft it, or inspection shows that brood frames are not well ringed with honey, it is time to feed. You can use:

  • A strong sugar syrup at around 2:1 sugar to water.
  • Or a commercial inverted syrup designed for autumn feeding.

1 kg of granulated sugar typically provides around 1.25 kg of stored food once processed by the bees. Use a rapid feeder and offer larger feeds rather than small trickles, which can encourage robbing.

Aim to complete the bulk of feeding by late September or early October, while temperatures are still high enough for bees to evaporate water from the syrup and seal it properly. Late feeding in cold weather can leave you with unsealed, fermenting stores and stressed bees.

Finishing varroa treatments

If you haven’t already treated for varroa, early September is your last good window to do so before winter bees are fully raised. High mite levels reduce the lifespan and quality of winter bees, making colonies far more likely to fail before spring.

Review your plan in the Varroa Management guide and choose an approved product suitable for the local temperature and colony situation. Some thymol-based products may still be appropriate in early September, but always read the manufacturer’s instructions carefully.

If you have already completed a treatment in August, you may simply:

  • Continue to monitor drops on inspection boards.
  • Note any signs of deformed wings or other varroa-associated problems.
  • Plan any further oxalic acid treatment later in the winter when colonies are brood-light (if appropriate and used correctly).

Managing weak colonies and combining hives

For a colony to survive the winter, it needs enough bees to maintain a cluster and keep the brood and queen warm. A very small colony spread over just a few frames often struggles, even if it is well fed.

In September:

  • Assess whether each hive is queenright and has a good brood pattern.
  • Check the number of frames of bees – many beekeepers look for at least 5–6 good frames of bees for overwintering in a full-sized hive.
  • Check for signs of disease before moving any frames or bees between hives (see Bee Diseases and Pests).

If you have a weak but disease-free colony, it is often better to combine it with a stronger hive than to risk losing it over winter. The classic newspaper method is usually straightforward and gentle, just as described in the August guide.

Some smaller colonies can be overwintered in a nucleus box with close attention to feeding and insulation, but this is usually best done with local guidance and careful monitoring.

Preparing hives for winter

September is a good time to give each hive a basic “winter MOT”:

  • Check for gaps, cracks or rotten wood that could let in draughts or water.
  • Ensure roofs are sound and watertight and that hive straps or weights are ready for winter gales.
  • Make sure hives are on secure, level stands with good drainage underneath.
  • Consider tilting hives slightly forward so condensation and any leaks run out of the entrance rather than pooling inside.

This is also the time to check whether you need any additional insulation or windbreaks in your apiary, particularly in exposed sites. Simple steps taken now can prevent a lot of moisture and chill stress later in the season.

Entrances, wasps and mouse guards

As the weather cools, colonies naturally reduce flying, and you can help them defend the nest by managing entrances and guarding against pests.

  • Reduce hive entrances so there is a small doorway that bees can guard easily, especially on smaller or recently combined colonies.
  • Keep wasp traps out until the end of September and continue to keep the apiary tidy and free of exposed honey.
  • Fit mouse guards across the entrance before nights become cold enough for mice to start seeking winter shelter.

By this stage you should also remove queen excluders. If an excluder is left in place over winter, the bees may move up into the supers as a cluster and leave the queen behind to chill and die.

How often to inspect in September

September is usually the point where you can stop weekly swarm-control inspections. Swarming is unlikely and opening hives too often can disrupt the colony and chill brood.

Instead, focus on:

  • Checking stores and colony weight by hefting.
  • Confirming that each colony is still queenright and brood looks healthy.
  • Watching for signs of wasp pressure or robbing at entrances.
  • Verifying that entrances, mouse guards and hive repairs are all in place.

You may only need to open each hive briefly every couple of weeks, but keep observing flight lines, behaviour and traffic at the hive entrance whenever you are in the apiary.

Tidying and hygiene in the apiary

September is a natural time to catch up on general apiary housekeeping:

  • Cut long grass and clear away vegetation around hive stands for the last time before winter.
  • Check and repair hive stands, roofs and straps.
  • Clean and organise spare equipment – see the Hygiene page for safe cleaning approaches.
  • Store spare frames and supers securely against wax moth and rodents.

Good hygiene and tidy apiaries help to reduce disease pressure, minimise trip hazards in winter mud and make it easier to work around hives when conditions are less comfortable.

Records and ongoing learning

Beekeeping records are one of your most important tools. After each visit, note:

  • Colony strength and temperament.
  • Brood pattern and any concerns.
  • Approximate amount of stores and any feeding given.
  • Varroa monitoring results and treatments used.
  • Work done on equipment, entrances, mouse guards and weatherproofing.

Keeping consistent notes – whether in a paper notebook or in a digital system such as the BeezKnees HiveTag members area – makes it much easier to understand how your bees are doing over time.

September is also a great month to attend association meetings, talks or training events. With less pressure from swarm control, you can focus on building your knowledge ready for next season. See our Beekeeping Guides for more reading between meetings.

Common beginner mistakes in September

  • Leaving autumn feeding too late, so bees cannot properly ripen and cap syrup.
  • Underestimating how much food a colony needs to reach spring.
  • Trying to overwinter very weak colonies instead of combining them.
  • Failing to finish varroa treatment in time, leaving winter bees heavily parasitised.
  • Forgetting to fit mouse guards until mice have already moved in.
  • Leaving queen excluders on, risking the queen being left behind when the cluster moves.

If you are ever unsure, talk to your mentor or local association, or revisit key pages such as Hive Management, Varroa Management and Bee Diseases and Pests.

September beekeeping FAQs (UK)

What are the main beekeeping tasks in September in the UK?

Your main tasks are checking and increasing winter stores, feeding if colonies are light, completing varroa treatments, combining weak colonies, fitting mouse guards, reducing entrances and ensuring hives are weatherproofed for winter.

How much food should my bees have by the end of September?

By late September, a full-sized colony should be well on the way to having around 20–25 kg of stores. You may still need to top up with syrup in early October if the hive feels light when you heft it.

What syrup should I use for feeding in September?

A strong syrup around 2:1 sugar to water, or a ready-made autumn syrup, is ideal. Use a rapid feeder and offer larger feeds rather than frequent small amounts to reduce robbing risk.

Do I have to treat for varroa if I did it in August?

If you have already applied an effective, approved treatment and mite levels are low, you may not need another full treatment in September. However, you should continue to monitor drops and look out for signs of varroa-related stress.

When should I remove queen excluders?

Remove queen excluders before winter so the cluster can move freely through the hive. Leaving an excluder on can result in the queen being left behind when bees move up onto stores in cold weather.

Do I still need to worry about wasps in September?

Yes, wasp colonies can remain a nuisance in early autumn. Keep entrances reduced, traps maintained and the apiary tidy until at least the end of the month.

Is it okay to move hives in September?

Small moves within the apiary are usually fine if done carefully, but major moves are best planned for when flight is minimal and temperatures are moderate. Always seal entrances securely and follow the “three feet or three miles” rule where possible.