Tracking Bloom Dates for Better Beekeeping

June 15, 2019 Eric Miller

Eastern Tailed Blue Butterfly on white clover

It’s the middle of June and the nectar flow is going strong here in the American Midwest. But it’s about to come to a screeching halt. My bloom log (seen below) shows a big gap in the flowers available to bees between mid-June and late-August. Some of the flowers blooming now do help to bridge that gap, notably yellow sweet clover and cosmos; but as far as I know, there won’t be any major new nectar sources coming online until goldenrod and yellow ironweed start to bloom in large numbers in the early fall.

My ever-changing log of flower bloom dates near my bee yard

What does this mean to beekeepers? First, we need to be monitoring for the end of the nectar flow so we can start pulling honey supers for extraction. I do this by using a hive scale and watching for the weight of the hive to plateau or even start to fall. I don’t like to leave the supers on too long after that, because the large colonies will start to consume that honey before I can get to it. Once I pull supers, I’ll start feeding sugar syrup that includes a microbial supplement that helps ensure the bees have healthy digestive systems going into winter. I’ll also start focusing on integrated pest management, closely monitoring and managing varroa mites in each hive so the queens can lay a healthy crop of winter bees in September.

Your flow times may vary depending on where you live and what types of flowers are available within a few miles of your bees. I’ve compiled the bloom times of some common bee-friendly plants here in the Midwest; you can use this for general guidance, but also consider keeping track of bloom dates you see within a few miles of your hives each year. Doing so will improve your ability to make educated decisions about feeding, supering, and extracting. More importantly, in my opinion, it will make you hyper aware of your environment, more appreciative of your local flora, and may even provide first-hand insight into fluctuations and changes of your micro-climate from year-to-year.

How Many Bee Stings Would it Take to Kill You?

May 24, 2019 Eric Miller

I’ll go out on a limb and say that most beekeepers have considered the potential danger of their hobby at some point. We’ve heard tales about things going awry during an inspection, including the story about the long-time beek in England that died from one well-placed sting to the jugular. But most of us don’t worry excessively about our bees doing real harm to us, and I suppose those who do eventually take up watercolors or some other relatively nonthreatening pursuit. I came across this very interesting infographic on CompoundChem.com., which provides a lot of interesting facts on the venom of many insects, including our beloved honey bees.

But hypothetically, if we suit up in shorts and a t-shirt and get into a hot hive—or one that’s Africanized—just how many stings could we endure before we succumbed to them? The key piece of info on the above graphic is that a lethal dose of venom from a honey bee is 2.8 mg per kilogram of body weight. From that, we can do some figurin’…

Average weight of an adult male in North America: 178 lbs (80.7 kg)
Lethal dose required for average male: 80.7 kg X 2.7 mg = 218 mg
Approximate amount of venom in one honey bee sting: 59 micrograms
Stings per lethal dose: 218 mg / .059 mg = 3695 stings

So given a little bit of data, we conclude it would take 3695 honey bee stings to kill a 178 lb adult male. I personally have below-average weight (155 lbs), making my magic number 3217 stings. The most stings I’ve gotten in a single sitting is around 20-30, so something would have to go terribly wrong for me to reach that critical number. But I’m sure horrible things start to happen to the human body well before the lethal dose, and there’s that story of the British beekeeper that died from one well-placed sting…all things considered, I think I’ll keep wearing a veil.

Painted Hive Bricks

April 26, 2019 Eric Miller

When the green side of the brick is facing up, I know the hive was in good shape the last time it was inspected

This old nuc cover serves as a legend for my painted brick system

Like most beekeepers, I keep a journal to document my hive inspections. I also have a white board where I outline follow-up actions for each of my hives. Those methods of documentation are great, but neither allows me to look out over my bee yard and quickly know each hive’s status. To fill this gap, I bought a couple dozen construction bricks and six different colors of spray paint. I painted each brick’s six sides with a different color, and came up with a simple system to show the basic status of my hives.

There are two overall categories to my system—queenless and queenright. Different colors distinguish between a queenless hive that is actively raising a new queen (yellow), and one that shows no signs of building queen cells (red). For queenright hives, I’ve got colors to indicate whether they’re doing well and need minimal attention (green), threatening to swarm and need to be split (orange), or need to be treated based on the time of year or recent mite tests (blue). The last color is black, and would sadly be displayed on a deadout.

This system is very cheap—the bricks were around 60 cents each and you can often find inexpensive paint on the return rack at home improvement stores. I’m not advocating to replace beekeeping journals with painted bricks, because it’s still a good idea to detail your actions and observations in writing. But for a reasonable price and little effort, you can use painted bricks to quickly scan your hives and get a pretty good idea of how your bees are fairing.

Swarm Traps Deployed

March 23, 2019 Eric Miller

We’re experiencing Fonzie-like weather right now—cool, but not harshly cold. Cool enough to change the song on a jukebox with the snap of a finger, but still warm enough to take full responsibility when it burns down Arnold’s diner. (Okay, suppressing my desire now to make this whole thing a Happy Days reference.) What I’m trying to say is that I can’t comfortably do full hive inspections because it’s still topping out in the 40s. But on sunny days this week my colonies were bringing in a lot of pollen, presumably from blooming maple trees. That new-found abundance of pollen makes me worry that some of the stronger colonies could already be thinking about swarming. So before their scout bees settle on a tree cavity, I went ahead and put out a couple swarm traps a few weeks early. I’ve already seen bees sizing them up, so I’m glad I hung them few weeks earlier than normal this year. The downside to putting them out early is that the empty hives tend to attract other bugs, so they may not be pristinely clean during prime swarm season in May; I’m counting on the bees being mostly undeterred by a woodroach or two. Putting them out early also bears a small financial cost, because every week or two I’ll spray a little Swarm Commander into the entrances—not a huge cost, but it may double my yearly expense for swarm trap bait.

I’ve posted before about how I build swarm traps. I’ve had good success with these, saving me a few lost colonies. I’ve also seen at least one swarm ignore these traps and fly into the woods never to be seen by me again…breaking my heart the way Fonzie did to so many ladies in poodle skirts.

If Honey Were Firewood

February 18, 2019 Eric Miller

36 lbs of firewood—about the same amount of energy a honey bee colony uses each winter

How many cords of firewood would bees need to survive the winter? This sounds like a dumb question because it is a dumb question. I’m going to ask it anyway because I’m curious.

Kevin Inglin recently discussed the British thermal units (BTUs) available in honey on his podcast, and it got me thinking about the a colony’s winter honey burn in comparison to my own winter firewood usage. Kevin mentioned 4,400 BTUs per pound of honey—I couldn’t find a source for that number, so I had to use a different one. According to the USDA, honey has 304 calories per 100 grams. There are 454 grams in a pound, so this equates to 1,380 calories per pound of honey. Converting calories to BTUs reveals there are 5476 BTUs of stored energy in each pound of honey.

Meanwhile, the white oak I predominantly burn in my woodstove has an available heat value of about 6,930 BTUs per pound, according the figures on this University of Illinois Extension table.

My heating is far less efficient than a honey bee colony’s

Honey bees might go through about 40-50 pounds of honey in a winter; the honey provides nutrition to individual bees, for sure, but it’s also the fuel for generating heat to keep the cluster from freezing in cold weather. The exact amount of honey needed to overwinter is arguable and highly variable, but most beekeepers in northern climates try to have at least 40-50 pounds of honey on each hive going into the winter. So let’s use 45 pounds as a colony’s winter honey consumption. There are 246,420 BTUs in those 45 pounds of honey—about the same stored energy as 36 pounds of my firewood. (For context, the picture above shows 36 pounds of firewood.) At 4,200 pounds of seasoned white oak per cord, the bees are surviving on 0.8% of a cord each winter. So it would take 117 colonies to burn through the equivalent of a single cord of firewood. Sounds pretty efficient considering I go through a few cords each winter myself.

But which of us is really making the best use of our heating energy? Well, if an overwintering honey bee colony weights 10 pounds and burns the equivalent of 36 pounds of white oak, it’s using 3.6 pounds of cordwood per pound of colony. Meanwhile, my combined household weight is around 280 pounds, and we’re burning through 12,600 pounds of white oak, thereby using 45 pounds of cordwood per pound of family members. So the bees are 1250% more efficient with their heating than I am, and that’s not even taking into account that my body is generating its heat from food, independent of the firewood I use to warm my home.

So why does this matter? It doesn’t really. But it’s still fun knowing.