The Dreaded Dearth

Dearth is any time of year when there is not a great enough nectar supply to sustain a bee colony. During a dearth, your bees will either be consuming nectar/honey stored in the hive, or syrup that you feed them. Below we'll talk about some ways to identify when you are in a dearth and what to do about it.

Let's start with some basics:

Just because you see flowers, doesn't mean there is nectar. We have seen hives starve in a field of purple fireweed. Flowers need certain conditions to "turn on the taps" and those conditions are different for each flower.
Honey is survival food. Your bees will eat it if the alternative is starving to death but, as a rule, bees prefer nectar as it is far easier to digest.
Sugar syrup will satisfy your bees during a dearth better than honey will. It more closely mimics nectar, which is what they really want.

How to recognize a dearth

Hint: it has nothing to do with counting flowers.

You'll need to watch the behaviour of your bees to recognize when they are in a dearth. If you take notes and refer back to them for a few years, you will start to see patterns of dearth in your area. For example, we know that there is a local dearth in our area after the dandelions disappear and the dearth is over once the clover flowers.

Now more about the cues you will receive from your bees. These will vary a bit depending on the time of year, but here are some signs to watch for.

Early season dearth:

Dry frames. When you do a hive inspection, always note how much food is available to the hive. If the frames right around the brood nest are dry, that's a sign.
Dead larvae/pupae at the hive entrance. In extreme cases, the hive will start to cull brood because there is not enough food to go around.
Slowed brood production. A queen will stop laying if there is not enough food to satisfy all those new mouths to feed.
Less air traffic. There is much more activity at the hive entrance when there is lots of forage available.
Wayward bees. During a good nectar flow, bees are on a mission. If you're seeing bees in odd places (for us, it's around our back deck and patio door), then it is likely they are desperately searching for food.

End of season dearth:

Defensive bees. When the taps have suddenly been turned off, bees become much more defensive of the honey stores that will get them through winter. That means that anything (or anyone) who gets close to the hive is more likely to be identified as a threat and dealt with accordingly.
Ejected drones. As soon as the bees realize that there won't be any fresh food coming in, they start to get rid of the dead weight. Bye bye boys.
Slowed brood production. Same as above, but this time it won't pick up again until spring.
Robbing. If there is frenzied activity at the hive entrance, rather that smooth coming and goings, then another hive may be attempting to rob.
Wasps. Wasps need to eat, too. And when the nectar flow is over, they will smell out a bee hive. They will try to get in for the honey and will also shark around outside to eat dead or dying bees.

What to do about Dearth

The biggest must-do, particularly once the end of season dearth begins, is to reduce the entrances on your hives to help the bees guard against robbers and tape up any cracks between boxes or hive parts where robbers could enter. The security of a small entrance will not only protect their food stores, but also keep them calmer as they do not feel under attack.

We are big proponents of feeding sugar syrup during a dearth. This goes for both our mid-spring dearth, and our end of season dearth. We never feed with honey supers on, so we are 100% sure that no sugar water gets into the honey we will harvest.

Why we feed sugar syrup:

It more closely mimics nectar, which is what the bees want.
It stimulates the queen to keep laying eggs. When bees eat their stored honey, they shut down brood production. When they are fed sugar syrup, they continue to build their population.
It is easier for bees to digest and results in less bee poop. This is most important during long stretches of being stuck in the hive (rainy springs and cold winters) when pooping in the hive can spread diseases such as nosema.

If you choose not to feed, it is very important to keep an eye on how much food your hive has as the dearth goes on. It is counterintuitive, but a hive with a really big population (which we normally think of as a nice strong hive) is at much greater risk of starving during a dearth because there are so many mouths to feed.

You can store honey frames to feed to hives in such situations, or you can pull honey frames from hives with plenty to give to those without. If you are feeding honey, it works best to scrape the cappings off with a fork before putting it in the hive to encourage them to eat it. You also need to position it nice and close to the nest so that they will find it easily.

Take Notes!

As I mentioned above, it is possible to get to know the cycles of dearth and flow for your area by taking some notes throughout the season for a few years. By learning the patterns, you will be able to more effectively plan for and deal with periods of dearth.