1. This month's priorities

• Provide space in time to very strong colonies.
• Create nucleus colonies still early enough for them to develop properly.
• Measure varroa pressure before being caught out by a colony that still appears very vigorous.
• Prepare the harvest and already choose now the logic of the first summer treatment.
• Adapt every decision to the actual context of nectar flow, weather, and altitude.
• Depending on the context: migratory beekeeping and late nectar flows.

2. June in the apiary: the guiding idea of the month

Objective Understand why June is a pivotal month at the apiary, during which the colony remains very powerful but where several important decisions already determine the rest of the season.

In June, two opposite mistakes can catch the beekeeper out: letting a very strong colony run out of space, or believing that a vigorous colony is safe from any problem. The first promotes swarming, the second lulls sanitary vigilance, particularly regarding varroa, whose population grows rapidly precisely because brood is abundant.

In June, colonies are often at their peak development. Brood is still abundant, foragers very active, and intake can be significant if conditions remain favourable. This month does not, however, simply extend spring: around the summer solstice, on 21 June, the dynamic changes gradually. The queen's laying will then begin to decrease, building will slow, and the beekeeper's margin for action will shrink little by little.

June is also a highly contrasting month from the standpoint of resources. Depending on the region, it can still offer good nectar flows, particularly in mountain areas or on certain late-flowering plants, but it can also become a poorer month, or even a dearth month in lowland areas once the major spring flowering is over and the weather deteriorates. A lowland apiary, a hillside apiary, and a mountain apiary do not necessarily follow the same rhythm.

Interventions must therefore not be guided by the date alone, but by observation of the colonies, the stores, the weather, and the resources actually available. Several challenges are concentrated in this month: managing space, creating nucleus colonies, monitoring the brood, measuring varroa pressure, preparing the harvest, and anticipating the summer control. Some of these challenges cannot be postponed until July. That is the true characteristic of June.

Further reading

• Good practices for inspecting a colony
• Brood nest volume
• Integrated varroa control through the seasons
• Apiary management: beekeeping management plan

3. Priority tasks for the month

3.1 Adding supers and managing space

Objective Provide the colony with the volume required to support the harvest, preserve the laying area, and limit the tensions that promote swarming.

What to watch
The very densely occupied brood box, bees overflowing, disorderly storage of honey or pollen in the brood box, and white wax constructions on the frame lugs or under the crown board. These signals often indicate that expansion must not be delayed.

Concrete actions
Provide space according to the colony's actual strength and the intensity of the nectar flow. Add a super when lack of space becomes a concrete risk. Support the colony's actual development rather than adding volume as a matter of principle. Also take advantage of June to have combs built while colonies remain very active.

Points of vigilance
Lack of space rapidly alters the colony's internal balance. The brood nest becomes blocked, laying decreases, and the beekeeper loses part of the management margin. The super is therefore not only a storage volume: it contributes to maintaining a balanced internal functioning. A strong colony may sometimes require one, two, or even several successive supers. Waiting too long remains a concrete risk, even in June. After the solstice, building capacity often decreases.

Further reading

• Practical Guide: 4.12 Dynamic colony management
• Frame construction
• Practical Guide: 4.4 Comb renewal
• Preventing swarming

3.2 Creating nucleus colonies and rearing queens: a closing window

Objective Take advantage of colony strength to multiply the apiary and renew queens, knowing that this possibility rapidly narrows as the month progresses.

What to watch
The actual strength of the parent colony, the presence of sufficient brood, bees, and food, the resources still available, and the priority objective of the apiary: harvest, stock renewal, or relieving a very powerful parent colony.

Concrete actions
Create a nucleus when this serves a clear objective. Use very strong colonies to renew the stock, provide reserve units, and lighten an overly powerful parent colony. For small apiaries, stay simple and realistic: form a nucleus colony with brood, bees, food, and good thermal regulation. For more advanced beekeepers, June also allows more structured queen rearing to be integrated, a few queens to be produced from a good breeding stock, mating hives to be prepared, or certain queens to be mated at a mating station.

Points of vigilance
When the nectar flow is ongoing and the main objective remains the harvest, lack of space and brood nest blockage must be avoided first. If, on the contrary, the aim is to renew the apiary or to relieve a very powerful parent colony, creating a nucleus may become a priority. The right choice therefore depends on the colony's actual strength, the available resources, and the beekeeper's objective.

From late June onwards, very simple methods of creating a nucleus with a small number of frames become too late. A nucleus colony created too late will not have time to develop sufficiently to overwinter in good conditions. Past this point, stronger units must be assembled, with more brood. This is not impossible, but it is more demanding. It is better not to let the opportunity pass at the start of the month. The quality of the initial breeding stock remains decisive.

Further reading

• Creating nucleus colonies and queen rearing
• Creating nucleus colonies
• Multiplying a nucleus colony
• Principles and methods of queen rearing

3.3 Recovering swarms and following up colonies that have swarmed

Objective Intervene with discernment regarding June swarms, taking into account apicultural interest, sanitary risks, and the essential follow-up of the parent colony.

What to watch
Whether the origin of the swarm is known or not, the local sanitary context, the state of the parent colony after swarming, the stores, the available space, and the risk of robbing if resources become scarce.

Concrete actions
Recover and hive a healthy swarm of known origin. After hiving, ensure that there is no excessive empty space, provide food if necessary, and monitor the actual development of the new colony. In the parent colony, remove or redistribute the supers if the harvest is not imminent, check the stores, and, after a sufficient interval, verify the presence of a queen by observing the resumption of laying.

Points of vigilance
Swarms located in a European or American foulbrood standstill zone must not be recovered: the risk of contagion is significant. When in doubt, the advice of the bee inspector is required before any decision. A colony that has swarmed is not automatically "sorted out": it enters a new phase of management. From a selection standpoint, it is worth considering replacing the queen of a recovered swarm. Perpetuating a strongly swarm-prone genetic line is not desirable in the long term. This is not a systematic obligation, but it is a decision that deserves to be made consciously.

Further reading

• Practical Guide: 1.4.6 Swarm
• On foulbrood contagion
• Practical Guide: 4.7.4 Management of queenless colonies
• Practical Guide: 4.8.3 Robbing
• Practical Guide: 4.7.3 Recognising healthy colonies

3.4 Preparing the harvest and the immediate follow-up of the season

Objective Anticipate the harvest and do not postpone to July the logistical decisions that must be taken calmly in June.

What to watch
The actual maturity of the honey, the state of the supers, the capping, the water content if possible, as well as the actual calendar of the apiary and the location of the colonies.

Concrete actions
Prepare the honey house, check equipment cleanliness, and only harvest honey that is sufficiently mature. Approach the harvest first from a quality perspective. Where supers are approaching maturity, the decision must be guided by the actual state of the combs and, if possible, by the water content, not by the date alone.

Points of vigilance
June is still a preparation month, but it is the last month when several decisions can be taken calmly before the pressure of the harvest and the rise of varroa reduce the room for manoeuvre. What is not decided in June will often have to be improvised in July, with less margin and more risk.

Further reading

• Managing the water content of honey
• Optimising good beekeeping practices for honey production

4. Bee health

Objective Make June a month of active sanitary observation. The apparent vigour of a colony does not protect against a silent rise of varroa, and each week of delay in diagnosis has a direct biological cost.

The best prevention is strong, healthy colonies
It is not necessary to know every disease. The essential thing is to be able to recognise a healthy colony and then identify what deviates from it. When in doubt, it is better to ask for help quickly and contact the bee inspector.
Useful practical guide: 4.7.3. Recognising healthy colonies

Varroa

What to watch
The brood, the natural mite drop, any anomalies on the frames, signs of patchy brood, European or American foulbrood, chalkbrood, varroosis, or any other anomaly.

Concrete actions
Carry out the final drone brood removal before the first summer treatment if this biotechnical measure was put in place in spring. Measure the natural mite drop to obtain a first quantitative diagnosis. In Switzerland, it is generally considered that, in late June to early July, a natural mite drop of more than 10 varroa per day means that one should no longer wait. If infestation proves high, prepare the summer treatment without delay, or even examine an emergency measure rather than improvising at the apiary.

Points of vigilance
Varroa does not only prepare autumn problems. In June, it can already disturb colony dynamics, harm the brood, and compromise the rest of the season. The rapid growth of its population at this time, precisely because brood is abundant, makes any delay costly. The natural mite drop threshold must be interpreted with caution: it presupposes a correctly performed measurement and does not exempt one from assessing the overall situation of the colony and the apiary. When in sanitary doubt, it is better to seek precise advice from the bee inspector than to let a poorly understood situation become established.

American foulbrood and European foulbrood
In the middle of the brood period, any clear anomaly of the brood nest must raise a red flag. Patchy brood, flaccid or discoloured larvae, sunken or perforated cappings, an abnormal odour, or a suspicious ropiness test must not be trivialised.
Practical guide: 2.1. American foulbrood / 2.2. European foulbrood

Sacbrood Virus (SBV)
Sacbrood can also appear during the brood season. It manifests as patchy brood and stretched dead larvae with the appearance of a liquid-filled sac, which can then dry out into a boat-shaped scale.
Practical guide: 2.11. Sacbrood Virus (SBV)

Asian hornet
In June, the Asian hornet colony develops gradually, but pressure in front of the hives often remains limited. It is useful to observe, without dramatising, the surroundings of the apiary, watering points, and sheltered spots. At this stage, there is in principle no reason yet to install a muzzle or a meshed entrance guard; in case of suspicious observation, document and report on frelonasiatique.ch.

 

Further reading

• Practical Guide: 1.5.1 Measuring the natural mite drop
• Practical Guide 1.1: Varroa management concept
• Practical Guide: 1.7.1 Emergency treatment – stack hives
• Recognising bee diseases

5. Stores and resources of the moment

Objective Correctly read the apiary's nectar flow situation and avoid believing that an active June automatically guarantees sufficient resources.

What to watch
The colony's actual stores, the weather, the evolution of flowering, the difference between lowland, hillside, and mountain, foraging activity, and the risk of dearth once the major spring flowering is over.

Concrete actions
Adapt management to the resources actually available. Where the nectar flow remains good, continue to support strong colonies. Where resources decrease, stay attentive to stores, to slowing intake, and to the risk of robbing. After recovering a swarm, provide food if necessary and monitor the actual development of the new colony.

Points of vigilance
June can still offer good nectar flows, particularly in mountain areas or on certain late-flowering plants, but it can also become a poorer month, or even a dearth month in lowland areas once the major spring flowering is over and the weather deteriorates. A lowland apiary, a hillside apiary, and a mountain apiary do not necessarily follow the same rhythm. Decisions must therefore never be guided by the date alone.

Further reading

• Practical Guide: 4.8.3 Robbing
• Brood nest volume
• Apiary management: beekeeping management plan

6. In the workshop / organisation

Objective Prepare upstream the logistics of the harvest and the first summer treatment, while the apiary still leaves some organisational margin.

In June, it is often too early to apply the first summer treatment, but it is not too early to prepare it. It is indeed the right moment to decide how the rest of the season will be managed.

It is not enough to know that the treatment will take place after the harvest: the logistics must already be chosen, the equipment prepared, the calendar considered, and the location of the colonies taken into account.

For the first stage of the summer treatment, two main options can be considered:

• Formic acid treatment after the supers have been removed. This method is simpler to implement, but it depends strongly on temperature. During heatwaves, overly rapid evaporation can become more difficult to control.
• Oxalic acid treatment in a broodless state, made possible by a prior brood break. This approach is less dependent on climatic conditions and offers high efficacy, but it is more technically demanding: it requires locating the queen, following a rigorous calendar over several weeks, and mastering the protocol properly.

If a brood break through queen caging is being considered, the thinking must begin in June, at least 21 days before the oxalic acid treatment. Implementation then takes place according to the chosen method, the apiary's calendar, and the local context. Its success largely depends on upstream preparation: equipment available, queen located, calendar established. This decision cannot be improvised at the last moment.

Further reading

• Practical Guide: 1.6.1 Brood break
• Varroa control: the summer brood break
• Integrated varroa control through the seasons

7. Depending on the context: migratory beekeeping and late nectar flows

Objective Present migratory beekeeping as a real June practice, useful in certain contexts, but one that requires serious preparation on the practical, sanitary, and legal level.

When resources decrease in lowland areas, certain production colonies can benefit from being moved to later sites, particularly at altitude. Migratory beekeeping is not only about seeking more honey. It also allows one to take advantage of later phenology and can, in some cases, facilitate certain summer management procedures, since mountain temperatures often remain more moderate than in lowland areas.

What to watch
The actual nectar flow availability, the choice of site, recommended distances, the agreement of the landowner or the relevant authorities, the sanitary and administrative situation, standstill zones, notifiable diseases, fire blight, any cantonal requirements, notification to the competent bee inspectors, informing neighbouring beekeepers, the hive record sheet, hive identification, ventilation, load securing, and the actual strength of the colonies.

Concrete actions
Carefully prepare the move. Verify that the nectar flow availability truly justifies migratory beekeeping. Choose the site carefully. Clarify the authorisations. Check the sanitary and administrative situation before departure. Keep the hive record sheet up to date. Transport colonies that are strong, healthy, properly ventilated, and have sufficient stores. Move hives generally early in the morning or during the night, with suitable equipment and well-thought-out logistics. Once on site, maintain regular monitoring.

Points of vigilance
The transport itself cannot be improvised. Migratory beekeeping must be prepared rigorously on the sanitary, administrative, and logistical level. It becomes relevant only if the nectar flow context truly justifies it.

Further reading

• Practical Guide: 4.9.1 Moving bee colonies
• Practical Guide: 4.9 Choice of apiary site
• Practical Guide: 4.7.3 Recognising healthy colonies
• Apiary management: beekeeping management plan

8. What we don't do now

Objective Avoid timing mistakes that become costly from June onwards, because several decisions can no longer be postponed without consequence.

• Do not let a very strong colony run out of space on the pretext that the season is already advanced: brood nest blockage and swarming pressure remain real risks.
• Do not postpone the measurement of the natural mite drop to July: already in June, each week of delay in diagnosis has a biological cost.
• Do not recover a swarm located in a European or American foulbrood standstill zone: the risk of contagion is too significant.
• Do not launch a simple method of creating a nucleus with few frames too late: from late June, time often runs short for forming a nucleus colony capable of overwintering well.
• Do not improvise migratory beekeeping, the harvest, or the strategy of the first summer treatment: sanitary, administrative, logistical, and calendar aspects must be thought through upstream.

In July, the rhythm will change again: the harvests, summer treatments, and preparation of the winter bees will take up more space. June is therefore the last month in which some latitude still remains — provided it is used to observe, decide, and anticipate.

---

► The other months...

| January | February | March | April | May | June | July | August | September | October | November | December |