Interventions according to Bretschko

As a matter of fact, we should open our hives as little as possible, even if we don’t always stick to that principle out of pure curiosity…

Josef Bretschko, whom I have mentioned before on these pages, described in his beekeeping method the minimum number of interventions during the bee year to remain master of the situation at all times. Below is a brief summary, which, in my view, is still a good approach to beekeeping.

Check of wintered colonies

By mid-March or early April, depending on the weather. The indicator is the start of willow flowering.

Objectives: Check for queenrightness and colony health. Determining food supply and colony strength. Space correction of weak colonies, possibly uniting these with stronger ones. Cleaning or changing bottom boards.

At this point of time, brood should be present in all colonies. If not, the colony is queenless or the queen is no longer good. Such colonies can be united with a split of last year if there are still enough healthy bees present.

If there are sunken cell covers, dead larvae, many mummies in the cells or on the Varroa board, it is safer to eliminate the colony.

There must be at least 10 kg of food available so that the colony can bridge the gap until the spring nectar flow starts. If there is too little food available, adding frames containing food stores – preferably from a well-supplied colony – is the most elegant solution.

Colony strength at the end of winter depends first of all on colony strength at the onset of winter and on the quality of the winter bees (Varroa!). If colonies have shrunk too much during winter, it is recommended to reduce the available space.

If a colony is lost, no matter how annoying in itself, this should not be taken too seriously: it is natural selection at work, unless the beekeeper has made major mistakes. What needs to be analysed is why the colony did not make it. Keep in mind that even in the best of cases, about 10% of the colonies perish or are so weakened that they can no longer continue on their own.

Between end-of-winter check and spring revision, colony size continues to decrease because the production of young bees cannot yet keep up with the death of winter bees.

Spring revision

Should occur at the start of cherry and dandelion flowering, about 3 to 6 weeks since willow flowering.

Objectives: Checking health, brood condition and food supply. Elimination of weak colonies, possibly by uniting with another colony, after eliminating the unsatisfactory queen.

The spring revision coincides with the end of the first stage of colony development. Because there are still relatively few bees in the colony, it is a good time to carefully examine the condition of the brood. It is important to realise that if there are few bees, rapid expansion of the brood nest cannot occur either. One must also be aware that colonies have an (innate) difference in their rhythm of development. This makes it unavoidable to treat the colonies of the same apiary in a differentiated manner.

There are now so many young bees emerging that the disappearance of the winter bees is more than compensated for. If there is a long time between willow and cherry flowering, the development of the colonies is quite slow, with a low swarming tendency. But if the breeding curve runs very steeply, colony development can happen very quickly, with a correspondingly strong tendency to swarm.

At the time of the spring revision, there must still be at least 5 kg of food in the colonies, preferably in the lower box (if the colony is managed with 2 brood boxes), so that the upward trend of the queen is not disturbed.

During the cherry bloom, the tendency to build is at its strongest: this is the time to replace old empty combs. I place the frames containing foundation between a feeding frame and a pollen frame, not in the middle of the brood nest, so that this is not interrupted even during periods of adverse weather.

First correction intervention

Takes place some 2 to 3 weeks after the spring revision, at the time of flowering of apple and rapeseed. The colonies are now in the second phase of upward development and are growing stronger every day. The aim of the intervention is to slow down or even completely suppress the onset of swarming fever in the colony by providing space and encouraging comb building.

The colonies have now approximately reached their breeding maximum and are entering the critical phase. It is essential that the colonies are not hindered in their upward trend. If colony management is based on two brood boxes, care should be taken to avoid that the lower box fills up too much with bees. If no action is taken, the swarming fever will arise and the colonies will start preparing for this, even if additional space is subsequently given.

Colonies which are not yet ready for receiving a super are best eliminated, preferably by placing a strong colony on top of the weaker one, while removing the poorly performing queen, of course. Uniting two weak colonies does not work out well in practice.

After the first correction intervention, the brood nest should now quickly move upwards, as a sign of a tension-free development of the colony. This upward trend does not function sufficiently in the case of weak colonies.

The use of queen excluders does not stop this upward trend. However, it may somewhat increase the swarming tendency of the colony. On the other hand, its use has undeniable advantages for the control of swarming and when harvesting honey.

If queen cells are already present in some colonies, then the obvious option is to make a queenless split, with 2-3 brood frames and the bees adhering to these. Alternatively, one can make a temporary split, in which a Snelgrove board separates the queen from the main part of the brood: brood distancing. If you have a ripe queen cell for the queenless unit, some time can be gained, otherwise you must ensure that there is uncapped brood in the queenless unit, so that the bees can breed a new queen themselves.

Ultimately, the 2 units can be united again, eliminating the old queen. This is still in time for the main honey flow and all the more so for the flowering of the heather or giant balsam. If the 2 units of the temporary split are reunited, swarming fever may arise again.

Second correction intervention

Takes place 1 or 2 weeks after the first correction intervention, so in fact very soon afterwards. Maybe sometime between May 10 and 15 or 2 weeks later if spring turns out to be cold. The aim is to reduce tensions in the brood nest and maintain population strength for the main nectar flow. In practice this often implies swarm prevention.

The bees are now close to or have even already reached their breeding maximum. Swarming fever is present in many colonies and the beekeeper must deal with this during the second correction intervention. Swarming fever is influenced by many factors, both internal (genetic, colony strength, age of the queen) and external (honey flow, weather conditions).

If half of the brood is removed from the colony, swarming will be postponed. This can be realised by making splits including bees or by brood distancing, by making temporary splits. Both the tapping of bees and brood and brood distancing are at the expense of honey yield, but much less so than in case of the loss of a swarm. If the swarming fever iss very advanced, creating a temporary split ensures that the swarming fever disappears at least temporarily.

The determining factor in planning the intervention is not the age of the queen, but the developmental status of the colony. This implies that the intervention will not take place in all colonies.

Evaluation of food stores

During each correction intervention, the food stores should be evaluated. Available stores should never be less than 5 kg. If this amount is not present, additional feeding is required. However, at the same time care must be taken to ensure that the food given does not mix with later nectar. This is not always easy. When planning, one should keep a close eye on the long-term weather forecast. If you feed (your own!) honey, there is of course no problem.

The stockpiling of food by the colonies depends very much on the season. In spring, during the build-up phase of the colony, bees tend to consume a lot. Only during the reduction phase do they start to use the stored food stock more economically and carefully.

Honey harvest

The harvesting moment is determined solely by the ripening state of the honey. But migrating beekeepers have a slightly more restricted window of opportunity here than stationary beekeepers, as the timing of the migration to the next honey flow may force them to harvest. Extracting monofloral honey can also tempt the beekeeper to harvest before full maturation has taken place. But I prefer ripe mixed honey to unripe monofloral. In all cases, there must still be at least 5 kg of food stores remaining in the hives after harvesting in order to bridge the time until the next nectar flow or the time of wintering of the colonies.

Summer revision

At the latest in early August. Objectives: Completion of honey harvest. Health check. Classification of colonies by strength. Decide to overwinter in 1, one and a half or 2 boxes. Set-up of spare colonies, if necessary. Start winter feeding and Varroa treatment. If applicable, prepare colonies for late nectar flows of giant balsam, honeydew, heather.

After harvesting the honey, it is now decided which colonies will go into winter, and in particular which ones still need to be provided with a young queen. The performance of the colonies can be looked up in the administration. The quality of the breeding nest in particular is decisive here. During the summer revision, the available space is adjusted to the strength of the colonies.