How to Manage Bees During the Main Nectar Flow

The main nectar flow is the period when a strong colony can fill supers quickly, but it is also when congestion, swarming, varroa build-up and missed disease signs can cost you the season. Good management is about doing the right work at the right time: giving space before it is urgently needed, checking for swarm preparations, protecting honey quality, and keeping accurate hive records so every visit has a clear next action.

During the flow, aim for short, purposeful inspections. Confirm queenright status, brood health, available laying space, super space, swarm risk and any signs of disease. Record what you find, including brood frames, stores, supers, queen status, varroa counts and actions taken. A record-keeping tool such as Bee Hive Tracker is useful here because fast notes and photos reduce guesswork between inspections.

When is the main nectar flow in the UK?

There is no fixed UK date for the main nectar flow. It depends on region, altitude, weather, soil moisture and local forage.

As a broad guide:

• Southern and lowland England: often late May through June, with bramble, clover and lime extending into July in good areas.
• Midlands: commonly late May to July, depending on spring weather and available forage.
• Northern England, Scotland and uplands: usually later and often shorter, commonly June into July.
• Oilseed rape areas: a separate early, intense flow may occur in April and May. This crop granulates quickly, so honey often needs removing and extracting promptly once ripe.

Important UK nectar sources include oilseed rape, hawthorn, sycamore, horse chestnut, lime, field beans, bramble, clover, borage, rosebay willowherb and heather in suitable areas.

Weather is the deciding factor. Warm, settled, humid conditions with adequate soil moisture can produce a strong flow. Cold nights, wind, drought or prolonged rain can stop nectar secretion even when flowers are abundant. Local knowledge from nearby beekeepers, your association and your own hive weight records is more reliable than the calendar alone.

Main objectives during the nectar flow

Your priorities are to:

• Keep colonies strong enough to gather surplus honey.
• Prevent swarming before the colony loses its foraging force.
• Provide enough super space for nectar ripening and storage.
• Maintain brood nest space so the queen can continue laying.
• Monitor varroa and brood disease without contaminating honey.
• Harvest only ripe honey and leave colonies with a safe stores plan.
• Keep clear records so each colony is managed according to its condition, not memory.

Inspection routine during the flow

How often to inspect

For colonies at risk of swarming, inspect about every seven days during the main swarm season. This interval matters because queen cells can develop quickly, and a colony may swarm around the time the first queen cells are sealed.

Strong colonies not showing swarm pressure may need less disturbance, especially if you can assess super space and activity without dismantling the brood nest every time. However, do not stretch inspections if the colony is congested, has an older queen, or has already shown queen cells.

Choose warm, calm periods when many foragers are out. Work efficiently and avoid leaving brood exposed longer than necessary.

What to check before opening the hive

A quick external check tells you a great deal:

• Flight activity: steady, purposeful flying suggests forage is coming in.
• Pollen: pollen going in usually indicates brood rearing, though it does not prove the colony is queenright.
• Hive weight: heft the back of the hive or use scales if available. Rapid weight gain usually means nectar is coming in.
• Entrance behaviour: unusual clustering, fighting, wasps, dead bees or erratic activity may indicate robbing, disease, queen issues or congestion.
• Space pressure: bees bearding at the entrance in warm weather can be normal, but combined with a packed brood nest it may indicate overcrowding.

Record these observations before you open the colony.

A practical brood inspection sequence

Keep the inspection focused:

1. Check the supers first. Are bees working them? Is comb being drawn? Are the lower supers filling rapidly?
2. Remove supers carefully and cover them to reduce robbing.
3. Open the brood box and look for eggs or young larvae. You do not always need to find the queen if you can see fresh eggs.
4. Assess brood pattern. Look for a healthy spread of eggs, larvae and sealed brood.
5. Count frames of brood and frames of stores.
6. Check whether the queen has enough laying space.
7. Look carefully for queen cells, especially along the bottom bars, frame edges and gaps between brood frames.
8. Scan for disease signs: patchy brood, sunken or perforated cappings, twisted or discoloured larvae, unusual smells, chalkbrood mummies or abnormal numbers of dead bees.
9. Close up promptly and record actions and the next inspection date.

Useful records include queen seen or eggs seen, brood frame count, stores, number of supers, queen cell status, temperament, varroa monitoring results, disease concerns, photographs and the action taken. Bee Hive Tracker works well for this because the most valuable notes are often the ones made at the hive before details are forgotten.

Managing space and honey supers

Add supers before the colony is crowded

During a strong flow, colonies can fill available space quickly. Add supers before the existing super is packed with nectar and bees.

A practical rule is to add another super when:

• The current super is well occupied by bees.
• A good proportion of frames are being filled.
• The brood nest is crowded.
• The colony is gaining weight quickly.
• A strong flow is forecast to continue.

Drawn comb is far more valuable than foundation during the main flow. If you have drawn super frames, use them where the strongest colonies can fill them. Foundation can still be used, but bees need nectar income and warmth to draw it well.

Where to place new supers

Beekeepers use different methods, and both can work:

• Top supering: placing the new super above the existing supers. This is simple and reduces disturbance.
• Bottom supering: placing the new super directly above the queen excluder and below partly filled supers. This can encourage bees to move into the new space, but it involves more lifting.

In a fast flow, the best method is often the one that gives space quickly without excessive disruption.

Using a queen excluder

A queen excluder keeps brood out of honey supers and makes harvesting easier. Many UK beekeepers use one as standard once supers are on.

To help bees move through the excluder:

• Make sure the brood box is strong and well covered with bees.
• Use drawn comb above the excluder if possible.
• Avoid putting a full box of cold foundation over a weak colony.
• Check that the queen is below the excluder before closing up.

If brood is found above the excluder, confirm where the queen is, place her below, and allow brood above to emerge before extracting those frames.

Avoid brood nest congestion

Nectar stored in the brood nest can restrict the queen’s laying space and increase swarm pressure. If the brood box is becoming honey-bound:

• Add super space promptly.
• Move capped stores from the brood nest if appropriate, replacing them with drawn comb or foundation near the edge of the brood area.
• Consider brood-and-a-half or a double brood system for very prolific colonies, but only if you can manage inspections properly.
• Do not simply keep stacking supers if the problem is lack of laying space below.

Swarm prevention during the main flow

Swarm prevention is often the difference between a crop and an empty super. A colony that swarms may lose a large part of its flying bees just when nectar is available.

Early signs of swarm preparation

Watch for:

• Queen cups containing eggs or larvae.
• Charged queen cells with royal jelly.
• Queen cells along the bottom edges of brood frames.
• Heavy congestion in the brood nest.
• Reduced laying space.
• A sudden change in colony balance, with many bees and little open brood.
• An older queen or a colony with a known history of swarming.

Queen cups alone are not always a problem, but charged queen cells need action.

What to do if you find queen cells

If you find charged queen cells, do not rely on simply knocking them down. This often delays the issue only briefly and can leave the colony queenless if the swarm has already gone or the queen is damaged.

Choose a clear swarm control method and record exactly what you did.

Common options include:

• Artificial swarm: separates the queen from most of the brood and simulates a natural swarm while keeping the bees under your control. This is a reliable method when done correctly and suits colonies with a laying queen present.
• Nucleus split: removes the queen or queen cells with brood and bees to form a nuc. This can reduce pressure and provide a spare colony or queen.
• Vertical split: uses an additional brood box and separation board to divide queenright and queenless parts of the colony while keeping the units on the same stand.
• Demaree method: separates the queen and open brood from most sealed brood, often useful for strong colonies when you want to reduce swarm impulse while keeping honey production.
• Requeening: useful for colonies with poor temperament, failing queens or repeated swarm tendency, though it may not solve an immediate swarm crisis quickly enough on its own.

Whatever method you use, note the queen’s location, queen cell status, frame movements, box arrangement and the next inspection date. This is one of the most important times to keep accurate records.

Queen quality and brood management

A productive queen underpins the nectar flow. You do not need to see her every inspection, but you do need evidence that the colony is queenright and building properly.

Signs of a good queen

Look for:

• Eggs and larvae in a consistent pattern.
• Expanding brood area during the build-up.
• Mostly worker brood in worker comb.
• Good colony temperament.
• Strong foraging and steady super use.

Warning signs

Investigate if you see:

• Patchy brood with no obvious reason.
• Excessive drone brood in worker cells.
• No eggs or young larvae.
• Multiple eggs per cell.
• Emergency queen cells after a sudden brood break.
• A colony that is strong in bees but failing to expand brood.

Poor brood patterns can be caused by queen failure, disease, chilled brood, varroa damage, inbreeding or comb problems. Do not assume the queen is the only cause until you have checked for disease and mites.

Record queen age, marking colour, temperament and performance. Over time, these records help identify which colonies are worth breeding from and which should be requeened.

Varroa management during the nectar flow

Varroa levels can rise while honey supers are on, but treatment choices are limited because honey for human consumption must not be contaminated.

During the main nectar flow:

• Do not use varroa treatments unless they are authorised for the situation and the label permits use with honey supers.
• Follow UK product labels and Veterinary Medicines Directorate guidance.
• Avoid improvised treatments.
• Monitor mite levels so you know whether urgent action is needed after harvest.

Common monitoring methods include:

• Natural mite drop using a monitoring board.
• Sugar roll or alcohol wash where appropriate.
• Drone brood uncapping as an indicator, not a complete count.

If mite levels are high during the flow, seek advice from an experienced local beekeeper, your association or the National Bee Unit. In many UK management plans, the main varroa treatment is applied after honey removal in late summer, followed by an oxalic acid treatment during a broodless winter period where suitable.

Record mite counts, dates, method used and any treatments. Colonies carrying heavy mite loads through summer often show poorer honey production, increased virus symptoms and weaker winter survival.

Disease vigilance

The main flow is not a time to stop checking brood health. Strong colonies can still develop disease, and moving supers or equipment between hives can spread problems.

Notifiable brood diseases

American foulbrood (AFB) and European foulbrood (EFB) are notifiable in the UK. If you suspect either, contact your local Bee Inspector or the National Bee Unit and follow official guidance. Do not attempt to treat or move suspect material yourself.

Warning signs include:

• Patchy brood pattern.
• Sunken, greasy or perforated cappings.
• Dead larvae in unusual positions.
• Discoloured larvae.
• Ropiness in suspect AFB scale or remains.
• Sour or foul smells, though smell is not always present.

Other conditions to watch for

Also keep an eye out for:

• Chalkbrood.
• Sacbrood.
• Deformed wing virus.
• Chronic bee paralysis.
• Nosema-related weakness.
• Queen failure that mimics disease.
• Starvation during a weather break.

Photograph suspicious frames, mark the hive, avoid exchanging equipment, and get advice promptly. Good records make disease investigation faster and safer.

Feeding during the flow

A strong colony in a genuine nectar flow should not need feeding. Feeding while honey supers are on risks contaminating the crop with sugar syrup.

Only consider feeding if:

• A colony or nuc is short of food.
• Bad weather has stopped foraging and starvation is possible.
• A split or queenless unit lacks flying bees and stores.
• You have removed honey and the colony has insufficient reserves.

If feeding is necessary, remove honey supers intended for extraction or isolate the feed from the crop. Use the smallest appropriate amount and stop as soon as the colony has enough food. Avoid spilling syrup, as it can trigger robbing.

How much honey to leave

Do not take honey simply because it is present. A colony needs enough stores to survive poor weather, brood rearing demands and the transition into autumn.

For winter, many UK full-sized colonies need roughly 18–25 kg of stores, with higher requirements in colder, longer-season or exposed areas. Local practice matters: colonies in parts of Scotland, northern England or windy uplands may need more than colonies in sheltered southern areas.

During the main flow, ask:

• Is this colony strong enough to spare the honey?
• Is more forage expected?
• Will I feed after harvest if needed?
• Is the colony queenright and healthy?
• Are there enough stores below the supers if weather turns?

If you take honey, record the date, hive condition, number of supers removed and any feeding plan.

Harvesting honey during and after the flow

Harvest timing affects honey quality.

Only extract honey that is ripe. Good signs include:

• Most cells are capped.
• Uncapped honey does not shake out when the frame is held horizontally and given a firm shake.
• Moisture is within safe limits when checked with a refractometer.

UK honey is generally expected to be no more than 20% moisture, with different limits for some specialist honeys such as heather. If in doubt, test before extracting, especially after humid weather.

Take particular care with oilseed rape honey, which granulates rapidly in the comb. Remove it promptly once ripe, extract without delay, and avoid leaving it until it sets hard.

When removing supers:

• Use clearer boards, bee escapes or other low-stress methods.
• Avoid leaving wet supers exposed.
• Keep harvested supers covered to prevent robbing.
• Maintain clean extraction and storage conditions.
• Follow honey labelling and food hygiene requirements if selling.

Robbing, wasps and late-flow problems

Robbing often starts when a strong flow slows or stops. Colonies that were calm and busy can become defensive, and exposed honey can attract bees from across the apiary.

To reduce robbing risk:

• Keep inspections short.
• Cover supers and brood boxes when removed.
• Reduce entrances on weak colonies.
• Avoid spilling syrup or honey.
• Do not leave comb, wax cappings or wet supers open in the apiary.
• Feed only when necessary and preferably in the evening, using internal feeders.

Wasps become more troublesome later in summer. Strong colonies usually defend themselves well, but weak nucs and small colonies may need reduced entrances or moving to a more defensible setup.

Temperament, handling and PPE

Bees may be easier to handle during a good flow because foragers are occupied, but this is not guaranteed. Genetics, weather, queen status, robbing pressure and forage type all affect temperament.

Good practice:

• Wear suitable protective clothing.
• Use smoke sparingly but effectively.
• Work smoothly and avoid crushing bees.
• Close hives promptly.
• Avoid major manipulations in thundery, cold or windy conditions.
• Record temperament consistently.

If a colony is repeatedly aggressive without an obvious temporary cause, plan to requeen from calmer stock.

Record-keeping during the main nectar flow

Accurate records are practical, not administrative. They help you decide when to add supers, when to inspect again, whether a colony is preparing to swarm, and whether honey can safely be removed.

Record at each inspection:

• Date, apiary and hive ID.
• Weather and flow conditions.
• Queen seen, eggs seen or queen status uncertain.
• Queen age, marking colour and origin if known.
• Frames of brood.
• Frames of stores.
• Number and condition of supers.
• Whether comb is drawn, filling, capped or untouched.
• Queen cells: number, position and stage.
• Varroa monitoring results.
• Treatments and dates, where applicable.
• Disease signs or concerns, with photos.
• Temperament.
• Action taken.
• Next inspection date.

Bee Hive Tracker is particularly useful during the flow because you can record quick observations, photos and next actions at the hive, then compare colonies across the apiary later.

Compact main flow inspection checklist

Use this as a quick field checklist:

• Is the weather suitable and are bees flying well?
• Is the hive gaining weight?
• Are supers filling, drawn or ignored?
• Is more super space needed?
• Are eggs or young larvae present?
• How many frames of brood are there?
• Is the brood pattern healthy?
• Is the brood nest congested or honey-bound?
• Are there queen cups or charged queen cells?
• Are there signs of AFB, EFB or other disease?
• What is the latest varroa monitoring result?
• Is the colony calm, defensive or abnormal?
• What action was taken?
• When is the next inspection due?

Troubleshooting common main flow problems

Supers are not being used

Possible causes include a weak colony, cold weather, lack of drawn comb, a restrictive queen excluder, insufficient bees, or no real nectar flow. Check colony strength and forage conditions before adding more boxes.

Brood nest is packed with nectar

Add super space, provide drawn comb if available, and create laying space carefully. Watch for queen cells, as honey-bound colonies often move towards swarming.

Charged queen cells are present

Act promptly using a proper swarm control method. Do not just destroy cells and hope the colony changes its mind.

Colony is weak during the flow

Check for queen failure, disease, varroa, starvation or lack of flying bees. Depending on the cause, you may need to feed, requeen, unite, add brood from a healthy donor colony, or seek disease advice.

Honey is uncapped late in the flow

Give the bees time if conditions allow. If harvesting is necessary, test moisture with a refractometer. Do not extract unripe honey and store it as saleable honey.

Mite levels are high but supers are on

Check authorised treatment options and label restrictions. If honey supers prevent treatment, plan immediate action after honey removal and seek local advice if the colony is at risk.

Broad UK month-by-month notes

May

Strong colonies may expand rapidly, especially in oilseed rape areas. Add supers early, monitor queen cells closely and extract oilseed rape honey promptly once ripe.

June

Often the key month for the main flow in many areas. Keep ahead of super space and swarm control. Short, regular inspections are usually more valuable than long disruptions.

July

Bramble, clover, lime and other forage may continue the flow. In some areas the season begins to slow. Start planning post-harvest varroa treatment and assess queen performance.

August

The main flow is often over except in areas with heather, balsam or other late forage. Remove ripe honey, monitor varroa, treat where appropriate, and begin preparing colonies for winter.

Final practical advice

Manage the main nectar flow with discipline:

• Add space before the colony is crowded.
• Inspect for swarm signs at sensible intervals.
• Take decisive action when charged queen cells appear.
• Keep honey supers free from feed and unsuitable treatments.
• Monitor varroa even if treatment is planned for later.
• Treat suspected AFB or EFB as urgent and reportable.
• Harvest only ripe honey.
• Keep clear records of queen status, brood, stores, supers, mite counts and next actions.

The colonies that perform best are usually not the ones inspected the longest, but the ones managed consistently, with accurate records and timely decisions.

Sources Used

• https://www.nationalbeeunit.com/
• https://www.gov.uk/guidance/find-a-bee-inspector
• https://www.bbka.org.uk/