A honey bee dives into a nasturtium flower.

Liz Miller is our guest blogger this month. She is using ThermaCork to build beehives in Washington state. In this interesting blogpost she details the inspiration for and creation of Cork Hives as well as the origin of her love of bees.

It’s all over the news: Pollinators, including the honey bee, are in trouble. Commercial beekeepers, despite feeding and medicating their bees, lost 40% of their hives last year. Hobby beekeepers often fare worse, losing all of the hives in their small apiaries each winter.

I've always loved insects, but I think my fascination with bees started when I was a little girl living in San Jose, California, and our neighbors kept honey bees. All summer long the bees came to drink out of our swimming pool, occasionally falling in and struggling sadly. Rescuing these bees and helping them dry out on the hot concrete was a frequent pastime.

All was well until one day, while I was goofing around in the backyard, I heard a tremendous buzzing. The air was filling with bees! Horrified, I ran into the house shrieking. Less horrified, I watched as the bees formed a giant cluster on a low tree branch. And now intrigued, I was a bit jealous of our neighbor as I saw him nonchalantly saunter up to the branch and give it a quick shake, knocking the bees into the cardboard box he placed below.

As I learned that day, the neighbor’s bees had no interest in me, they were swarming: when a colony splits itself into two or more parts and those parts fly off in search of a new home. While the bees are deciding where to go, they form a cluster, or ball of bees, on a tree branch, post, or sometimes even a car or building! The seed of my bee obsession was planted.

Many years (too many years) passed before I felt like I had the space and free time to start keeping bees of my own. I took an apprentice class through my local beekeeping association, and learned more about the struggles beekeepers faced, particularly in helping their beehives survive through winter.

Bee researchers such as Thomas Seeley think part of the problem is the sort of hives we keep bees in. Honey bees evolved mainly to live in tree hollows - voids left in trees by woodpeckers, fungi, or other factors. These hollows have walls that are several inches thick, providing remarkable temperature stability. The interiors are rough, triggering the bees’ instinct to smooth the walls with propolis, a substance they make from plant resins. This propolis not only strengthens the inside of the hive, but also boosts the bees’ immune system. Tree hollows used by bees are usually about 40 liters in volume, and of course never grow in size.

Contrast these tree hollows with the typical beehive: Thin walls that provide almost no insulation. Smooth interior surfaces that discourage immune-boosting propolis. A volume that continually grows throughout the season as beekeepers add more and more hive boxes, allowing populations of the varroa mite, bees’ main foe, to explode.

To boost my bees’ chance of survival, I wanted to keep bees in a hive that was as much like a natural log bee home as possible, while allowing me to check the bees for problems and help out when needed. But I couldn’t find a hive that offered all the features I needed: insulation, rough interiors, moveable frames, and all-natural sustainable materials. So, it was time to take up woodworking!

We set up one of our old, thick walled wooden hives as a "bait hive" in hopes a swarm would move in. One did!

In 2017, I started working on creating bee-friendly hives. I wanted to combine the latest research on bees in their natural log homes with an affordable, beekeeper friendly design. To provide more insulation, I began building hives out of two-inch-thick cedar lumber, which provided more than double the insulation of a standard pine box. Those hives were beautiful and sturdy, but pretty heavy. By the end of 2018, I was ready to try something different.

I also wanted to increase the insulation at the top of the hive, but I feared that hefting a roof made out of two-inch-thick lumber would land me in traction. I needed something lightweight and non-toxic. A bit of internet searching led me to ThermaCork.

After about 30 minutes, the swarm was almost done moving into the bait hive. The bees on the hive stand, with their abdomens in the air and their wings fanning, are using their Nasonov pheromone to signal the their sisters into the hive.

Bees peek from the entrance of a Cork Hive

Cork! I was intrigued. It has four times the insulation power of wood, but weighs almost nothing. It’s all-natural and additive free, so there would be no worries about fumes. It’s also very resistant to rot, to withstand winters in the Pacific Northwest when nothing is ever dry. And serendipitously, the regional distributor of ThermaCork, Small Planet Supply, was only an hour away from my workshop. How could I resist?

I ordered some cork and was pleased with the look and the texture. It was easy to work with and was the perfect solution for insulating the hive roof. And since it worked so well for the roof, I decided to try insulating a whole hive with it.

In the spring of 2019, we installed bees in cork-insulated hives in our apiary. The bees thrived over the summer. One hive even built up enough to “split” into two additional hives. The hive boxes, while never light when filled with bees and honey, were more manageable than ones built with two-inch-thick lumber. I finally felt pleased enough with the design to want to share it with others, so I started my small beehive business, Cork Hives.

In addition to insulation, Cork Hives boast other bee-centered features. They are about 40 liters in volume, the optimal size for bee health according to researchers such as Thomas Seeley. We rough up the inside of the hives to encourage the bees to coat the surface of their home with propolis, which helps boost their immune systems. At the top of the hive, the moisture quilt provides even more insulation and prevents winter condensation from dripping down on the bees and freezing them.

We sometimes use an endoscope to peek inside the hives.

The Cork Hive is also beekeeper-friendly. The foundationless frames allow the bees full control over the size of the cells they build, while allowing the beekeeper to inspect the hive for signs of trouble like the infamous varroa mite - one of the biggest threats honey bees face. Because it uses standard Langstroth frames, the Cork Hive is compatible with other beekeeping equipment in terms of making splits (dividing one strong hive into two or more new colonies).

Of course, winter is the real challenge. Bees grapple with many hardships: pests like the varroa mite, cold snaps, pesticide exposure, and long periods without forage. We’ll continue monitoring our bees, who so far are braving the winter.

At Cork Hives, we believe that keeping bees in ways that mimic nature, while giving them a helping hand when needed, offers hobby beekeepers the best chance of success. By offering bees a cozy home just like the ones they choose for themselves, the Cork Hive nurtures the partnership between people and honey bees. And the cornerstone of our hives is, of course, affordable, lightweight, all natural, super-insulating Thermacork!

To learn more about Cork Hives, please visit corkhives.com.

Small Planet Supply Blog

Beekeeper Uses ThermaCork in Innovative Cork Hive Design