Oregon State Beekeepers Association

Home for Oregon Beekeepers

Beekeeping Tips for May

by Todd Balsiger

Updated 5/17/09

  • Like last month, the overriding objective is for all colonies to be queen-right, healthy, and well fed so they can build up to maximum populations for the onset of the major nectar flow. The major nectar flow begins in most areas by late May.
  • Light hives can still starve if the weather turns bad. After the maples and fruit trees bloom there is actually a decrease in available nectar until the summer nectar flow begins in earnest. Although very infrequent, in past years it has been necessary to feed well into summer to prevent starvation. Simulative feeding can be done at this time prior to the main flow, but discontinue before supering!
  • Swarming is at its zenith in May (end of April too), so continue swarm control practices. The following phrase still has meaning: a swarm caught in May is worth a load of hay; a swarm caught June is worth a silver spoon; and a swarm caught in July ain't worth a fly.
  • Nuc boxes containing one frame that has had brood (a dark frame), one frame with honey and pollen, and the balance foundation are ideal for catching swarms. Swarms draw out foundation fast and do an excellent job. Remember frames need to be tight together when drawing foundation– too much space and the likely result will be burr or misshapen comb. You can feed sugar water to accelerate growth just like for divisions.
  • Consider setting up decoy hives (just like the nuc box above) to catch stray swarms in your apiary.
    Make sure the mice can't get in!
  • More on swarms… Decreasing queen pheromone production and its distribution within the hive triggers the swarm impulse, so the two best ways to reduce swarming are to regularly requeen (young queens produce more pheromones) and to reduce congestion (reversing, equalizing, splits).
  • Visually look at colonies for health and investigate why some hives are not keeping up with their peers… Does it have an underperforming, old queen? Has it become queenless and developed laying workers? Does it have a disease? Has it swarmed (don’t destroy the swarm cells!)? Are they raising a supercedure queen? Take appropriate action (which could be doing nothing). If you don’t know what to do, go to your next local beekeepers’ association meeting and ask.
  • Look for signs that it is time to super, e.g., the bees lose interest in syrup, the bees have zero robbing tendencies, and you see a new film of white wax especially on the top bars.
  • Provide abundant room for storing honey early in the season. I consider two supers as abundant. If paradichlorobenzene crystals are used for wax moth control, then air out supers on a warm day to vaporize its residues.
  • Bees work from the center up, so foundation centered in the hive will be drawn the fastest. In general, always use 10 frames when drawing foundation to prevent burr and misshapen comb. After the frames are drawn, it is recommended to go to 9 frames for supers to make uncapping easier. For brood boxes, either 9 or 10 frames are okay.
  • Research has found no difference in top-supering vs. bottom-supering. Do what is easier for you. Just like whether to run 9 or 10 frames per brood box, top-supering vs. bottom-supering is one of those highly debatable issues among beekeepers.
  • I recommend queen excluders (there are exceptions). I consider brood in supers as a big problem and hassle. Not the least of which are frames that have had brood are dramatically more attractive to wax moths and will require extra protection.
  • Bees collect water in the summer as avidly as nectar and pollen. If appropriate water resources are absent, provide water early and let the bees train themselves to use it. This is especially important for urban settings – where your bees may end up in your neighbor’s swimming pool or pet bowl instead.
  • Varroa mites: You may want to sample to estimate your varroa mite load, and treat if its high. This may be your last opportunity to treat with controls that have short withdrawal times before supering but require higher daily high temperatures for use. In the April (2009) American Bee Journal, Randy Oliver states that maybe the U.S. should adopt a lower threshold that the Europeans have adopted: around 1000 mites total for a moderately strong hive of 30,000 bees. The previous threshold number that I cited in the February/March Beeline was 3200! See the article for more details.

See a contact list by location of beekeepers who collect swarms of honeybees.


See a contact list of beekeepers who provide pollination services.


Download the Farm Direct Rules PDF document.


Download the OSBA Membership form.


Download the Oregon Dept of Agriculture Hive Registration form.


View or download the Endowment Agreement with Oregon State University.


View instructions for donating to the OSU Endowment for the Northwest Apiculture Fund for Honey Bee Research, Extension and Education.

Many of the forms and documents on this site require the Adobe Acrobat Reader software. It is available for download for free at www.adobe.com.

Download Adobe PDF Reader