Season by Season Instructions

The life cycle of most solitary bees fits into a regular pattern. They overwinter as dormant adults in cocoons, and about the time that apple trees begin blooming in the spring and daytime temps are in the 50s, the first Orchard Mason males appear.  They eagerly wait by the nest for females to emerge a few days later, and mating quickly occurs at the nest site.

Nursery cells divided by mud

A day or two after mating the females begin searching for new nest sites, such as insect holes bored in wood, plant canes, gaps in siding, masonry weep holes and, of course, Plan Bee Houses, if they’re lucky enough to find one!

Each female constructs her own brood cells using mud (Orchard Mason Bees) or leaf pieces (Leafcutter Bees) to partition each brood cell.  She forages for pollen and nectar, and makes a pollen-nectar loaf upon which she deposits one egg.  She then seals the cell with either mud or leaf pieces, and begins the process again, normally making 6 – 7 brood cells in a 6″ deep hole or nesting straw.  About one week later the eggs hatch and the larvae feed until they’ve eaten all their food supply, which takes approximately six weeks. By late June the larvae spin cocoons around themselves and have developed into pupae, or fully-formed adult bees, by late summer.  From September to April they remain dormant in a state of ‘diapause’ until the warm spring temps awaken them and the amazing cycle repeats itself.



Here’s a quick native beekeeper Calendar of Events (dates are approximate):

January/February:  Clean and seal bee house with mineral oil and add new inner nesting straws.

Late March:  Hang up your bee house.

April:  When plants are blooming, place your bees in the house.

Late May:  If you have a second bee house, hang it now to attract summer Leafcutter bees, but choose a shady spot.

Mid-June:  Remove filled straws and store in garage or shed, away from hot sun.

Mid-October:  Bee-filled straws go into fridge crisper drawer or unheated out-building for winter hibernation.

. . . and that’s all there is to it!

  In late Winter…

…when spring weather still seems a long way off, pick up your spirits along with some mineral oil from your local drug store and give your Plan Bee House a good coating. (Varnish or Polyurethane will also work, but only if you have a few months before nesting time for the odor to dissipate, otherwise the bees won’t nest in it.) Remove the cardboard tubes, and try to get the oil down into all the holes to keep them from swelling when wet. I learned the hard way that trying to stick Velcro onto a newly-oiled surface doesn’t work too well ;-), so if you use Velcro to attach your release milk carton to the bottom of your Plan Bee House,  don’t oil that area of the bottom.  If you oil your bee house every year, it will last a very long time!

Once the oil has had a couple of days to absorb, grab a handful of new, clean paper straw liners, place one inside each cardboard protector tube, and fill all the holes. This is very important since it provides clean nesting areas that result in healthy, parasite-free bee colonies. Now your bee house is ready for your bees, and all you need is warm spring weather!

  In early Spring…

…when plants and trees are blooming and daytime temps are consistently in the mid-50s, it’s finally time to hang your Plan Bee House outside.  Choose a warm, sunny location (facing east or southeast) where the bees will have the early morning sun to help them get moving, but are protected from wind and rain.  Higher than 4 feet is best to keep critters away, and against a solid wall is better than on a tree or fence post, since a large structure makes it easier for the bees to locate their nest site.  Make sure the house is very secure since any movement can dislodge the eggs from their food supply.

If you have bee cocoons from the previous season, see ‘In Spring’ below for details about how to introduce them to your Plan Bee House. Otherwise, the warm weather will hopefully attract some wild Orchard Mason Bees and soon you’ll see them flying in and out of the holes, gathering small piles of nectar and pollen, backing into the holes to remove pollen and lay their eggs, then collecting mud to safely wall each brood cell off from predators. Be sure your bees have a source of mud within 20′ for their wall-building!  After 6 – 8 weeks the females will have died but their eggs will develop into mature bees over the summer.

A Safe Bee Bag makes it easy to protect your baby bees.

Once you see the nesting activity drastically decrease (usually by early June) it’s very important to cover the holes to protect the eggs from predators like ants, wasps, birds and squirrels. It’s too early to move the bee house or nesting straws because you could easily dislodge the eggs from their food supply.  The easiest way to accomplish this is to purchase a Safe Bee Bag from our Store.

Protect your developing bees by wrapping your bee house.

Another easy option is to wrap the whole bee house in a piece of fabric that lets air through, but that insects can’t penetrate (like sheer curtains or an old tee shirt), tying it tightly around the hanging nail so insects can’t crawl in.  (Just be careful not to jar the house, since you might dislodge the eggs from their food supply.)  It might look strange, but I can guarantee that, without it, ants and tiny chalcid wasps will invade your nesting straws and kill many of your OMBs.  Now just let it hang while the bees are safely developing inside. . .



  During the Summer…

Telescoping Nesting Tubes provide the 3 hole sizes preferred by summer mason bees.

…Late May is a good time to hang up a second native bee house to attract summer pollinating Leafcutter Bees.  Just remember to hang it in a shady spot, since the hot summer sun can kill developing summer bee larvae.  We also offer Telescoping Nesting Tubes, which allow you to alter the hole sizes in your existing Plan Bee House to attract summer bees.  Summer mason bees are also non-stinging* bees, but they use small pieces of leaves or flower petals to divide their brood cells, rather than mud.  They normally appear just as the Orchard Mason Bees are finishing their nesting, and they will pollinate your summer flowers and vegetable gardens until early fall. The females will do all the work, so all you need to do is relax, admire your beautiful garden flowers and enjoy your delicious garden crops!

By mid-June it’s safe – and a good idea – to move your Orchard Mason Bee house out of the hot sun and into a garage or shed, since high temps can kill the developing larvae.  Remove the Safe Bee Bag or cloth cover and loosely wrap your bee house in aluminum foil to keep the mice from chowing down on the chewy bee grubs inside.  Then put it back in the Safe Bee Bag or cloth wrap to stop insects from getting in.

By late summer both the Orchard Mason Bees and the Leafcutter Bees will have formed cocoons around themselves and developed into adult bees. They’ll remain in this dormant state throughout the fall and winter, hibernating until temperatures start to rise again the following spring.

*Males don’t have stingers, and females will only stick you with their ovipositor if they are trapped.

  October is…

…the time to move your bees to a cool location so they can hibernate over the winter. Yes, you may just leave them outside in the bee house over the winter, but I don’t suggest it. Not only will the harsh weather age your Plan Bee House more quickly, the bees could begin to emerge during those odd warm spells we frequently experience during the winter and early spring. Without blooming plants for food, and with the eventual onset of seasonably cold temperatures, the males will die very quickly – dooming your entire year of native beekeeping. Storing your bee cocoons in your fridge during hibernation allows you to control when your bees emerge, ensuring that they’ll have enough blooming plants to feed on and that temps are warm enough for them to forage.

If you’ve attracted some Leafcutter Bees (LCs) to your bee house (their nesting straws will be capped with green leaf pieces rather than mud), there are many schools of thought as to how to care for them over the winter, since they develop at a different rate than Orchard Mason Bees (OMBs). Some say it’s best to store LC nesting straws in an unheated shed or detached garage, rather than in the fridge crisper drawer. This is a fine option, but just be sure to leave the inner nesting straws inside the cardboard tubes for added protection, and loosely wrap them in aluminum foil to deter hungry rodents.

The Orchard Mason Bee nesting tubes (capped with mud) may also be stored in an unheated outbuilding, but I highly recommend that you store BOTH species in your refrigerator crisper drawer instead, as outlined below.  Since the LC cocoons are wrapped in tiny leaf pieces, and are thus more delicate than the OMB cocoons, I suggest that you NOT open any nesting straw that is capped in leaf pieces. Just leave them in the cardboard outer tube and store them in your fridge along with your OMBs.

If your nesting straws are capped with mud and you want to open them, I’ve found that the easiest way to slide the bee-filled inner nesting straws from the cardboard tubes is to purchase a 5/16″ piece of wooden dowel from your local hardware store (costs about $1), or if you bought a Plan Bee House you’ll find one inside. Always try to push from the front of the straw, since the female bee usually leaves about a 1/2″ empty space after the outermost brood chamber. The dowel will push on the edges of the inner straw, rather than the bee cocoon, and the straws should slide out easily. If they don’t slide out easily, just leave them in the cardboard tube.

Instead of leaving the Orchard Mason Bee cocoons in the nesting straws until they emerge the following spring, you can drastically increase your bee populations by removing them from the straws. (Note that this does NOT apply to any leaf-capped straws of Leafcutter Bees, since those should not be unwrapped prior to storage.) This assures that the emerging bees won’t be trapped behind a dead bee, won’t have to crawl through mite-infested chambers, and won’t be attacked by tiny wasps — all before they reach fresh air!

So now you have a choice to make:  You can (1) leave the OMB cocoons in their inner nesting straws, or (2) unwind them to remove the individual cocoons.  I strongly suggest that you remove the OMB cocoons from the inner straws, since in the process you’ll eliminate any pollen mites, parasites, uneaten bee food, bee feces, and mud, resulting in more robust, healthy bees the following spring.

If you choose Door #1, pick a pretty day in early October and head outside with your nesting straws. (If you suffer from pollen allergies you might want to wear a dust mask, since you’ll certainly be handling unused pollen.)  Spread out some newspaper and carefully unwind the nesting straws – you’ll be fascinated by what you discover inside!  Watch the videos below, and check out my photos, to get a preview.  As you unwind the straws you’ll find some cells filled with tiny pollen mites, some cells filled with dozens of tiny chalcid wasp larvae, other cells empty because ants have invaded and stolen the bee larvae from its cell, and some cells containing the original pile of gorgeous yellow pollen and nectar, totally untouched.   It’s awesome!




It’s fun to see what’s inside, but if you’re not big on surprises, check out the two videos below to see what Chalcid Wasps and Pollen Mites look like in a nesting straw.  You can also see photos of things I’ve found in my straws by going to Look Inside in our Photo Gallery, and then you can make your decision. Remember that you should only unwrap the OMB mud-capped straws, but the LC leaf-capped straws should be left in their cardboard outer tubes.


Store your bee cocoons in your fridge crisper drawer to maintain dormancy until spring.


The bee cocoons can be safely refrigerated for 150 – 210 days at 35° F, but should never be stored for more than 220 days or they will start to emerge while still in your fridge!  Normally, placing them in cold storage in mid-October works out well for an early April release, but gives you some flexibility if the weather is not cooperating.

Storing them in containers that keep out the light reduces stress for the bees, so a simple box with air holes punched in it will work fine.  If you don’t unwind your nesting tubes you can leave them inside the cardboard outer tubes for better protection, then place them in an oatmeal container with air holes, or even a paper lunch bag.   If you’re keeping your bees in an unheated outbuilding or garage, be sure to choose a container that mice and rats can’t chew through, or wrap them in aluminum foil.

The bees can tolerate temperatures as low as 15° F for short periods of time if outdoors, but the ideal temp is between 35-41° F, so a regular refrigerator works well. To ensure that there’s enough humidity in your fridge to keep the bees from drying out, store them in the crisper drawer and be sure to place a wet sponge or paper towel (in a small plastic dish or baggie) in there with them.

That’s it! You’re all done till next spring when the fun begins anew.

  In Spring…

A milk carton makes it easy to watch your bees emerge.

…When plants and trees are beginning to bloom and your daytime temps are consistently in the mid-50s, it’s time to think about your bees once again!  Make sure all your cardboard tubes are filled with new, clean inner nesting straws, and hang your Plan Bee House in a nice sunny spot.  Assuming that your bee house attracted mason bees last season, now is the time to retrieve your cocoons from their winter storage spot and place them outside near your mason bee house.

Since observing the mason bees as they emerge from their cocoons and begin their nesting activity is really a highlight of this experience, here’s the easiest way I’ve found to both protect the bees from predators as they hatch, AND watch them emerge:

  • Locate a clean, waxed half-gallon paper milk carton and carefully tear open the top seal so you have easy access to the inside.
  • Remove and discard the screw cap on the pouring spout, since this will become the exit hole for the bees.
  • It’s important that the inside is as dark as possible, so the emerging bees will be drawn to the light of the spout exit hole.  There are many ways to accomplish this, but here are a couple of easy suggestions:  Cut a 1/2″ hole in a small box that has an end-flap opening; fold a piece of black construction paper and use it to line the back wall and sides of the milk carton; use any container that has a dark plastic lid (or line a clear lid with black paper, as I did in this photo) and cut a 1/2″ hole in the lid.  When you’re ready to view your bees just remove the lid.
  • Using a couple strips of heavy-duty Velcro (or twine, thick rubber bands, duct tape), securely attach the milk carton to the bottom of your Plan Bee House so that the pouring spout/exit hole is facing down.
  • Place your loose cocoons or bee-filled nesting straws in the middle of the dark container.  Always leave the spout exit hole uncovered, but when you’re not observing be sure to close up the ends of both containers.  You can secure the milk carton with a paper clip or clothes pin to keep your cocoons safe until you return to enjoy the show.
  • NOTE:  If  you also have Leafcutter Bee cocoons (they look like little green cigars ;-), they can also be placed in the milk carton.  However, they will not emerge until late May or early June.

Now, if you’re thinking that this whole ‘milk carton method’ sounds like a lot of trouble, and you don’t really care about watching the little guys hatch, here’s an alternative that might work better for you:

Remove one nesting tube from the bottom row of your Plan Bee House and gently place the loose cocoons into the hole so they’re resting directly on the wooden bottom. If you carefully tip the house back a bit, the cocoons will slide toward the middle where they’ll be protected from rain until it’s time for them to emerge.

Within a few days, weather permitting, the male bees will start chewing out of their cocoons (listen for the cool crunching sounds!)  They’ll wait patiently nearby until the females begin to emerge a few days later, and then they’ll mate.  (It may take several weeks for all the bees to emerge from their cocoons.) The females will begin laying eggs in the clean nesting holes you’ve provided for them. The bees usually emerge from their cocoons mid-late morning on sunny days, so be sure to keep an eye on them so you don’t miss the show!

After a couple of weeks all the bees should have hatched, but before you toss those dirty nesting straws in the garbage, gently unwind them to ensure that some bees aren’t trapped inside. You’ll be amazed at how many ‘bee lives’ you’ll save by doing this, and it’s almost always the females who are trapped at the very back of the straw. If you find any cocoons without exit holes, place them in a dish in the sun. If they contain healthy bees you’ll quickly see some activity.

Learning about native bees is so new to most of us that it can be overwhelming at first, but don’t worry! We email a seasonal ‘Stress-Reducing Newsletter’ that really simplifies it for you by reminding you of what you could or should be doing with your native bees during each season of the year. If you’re interested in receiving it, sign up now!

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