Post G25-002: Bee emergence.

 

A few days of warm weather, and my mason bees are emerging.

You have to read between the lines on various internet write-ups of bee emergence, but I’m pretty sure what you see above is a crowd of young male bees, doing what young males do best.  That is, hanging out, accomplishing nothing, and hoping to get laid.

The male bees emerge first.  And I guess they hang around, waiting for the female bees to emerge.

I’m still not entirely sure what the emergence box is for.  And I’m not sufficiently interested to stick a camera inside to see what’s going on.

Anyway, we got down to 5F this winter, and it doesn’t seem to have done these over-wintering bees any harm.

My next-most-recent post on bees is here:

Post G25-001: Finishing off my mason bee hotel duties

Post #2103: This and that.

 

Well,

a)  this is a blog, after all, and

b) if the President can flip flop daily on tariffs, then

c) it’s hard to see the shame in having a mere blog post that wanders a bit.


1:  AI replacement theory

1: Every human job that can be replaced by AI will be.

2: Every human job that requires speech and reasoning alone is at immediate risk of being replaced by AI.

3: All other human occupations will be condensed to the portions that can’t feasibly be replaced by AI.

 

These are laws of economics, not computer science.  New technologies have been doing this sort of thing since the start of the industrial revolution.  There’s nothing about this that’s entirely unique to AI.

This time, instead of technology making your biceps obsolete, now it’s making your brain obsolete.  The most important difference between the AI revolution and what has gone before is that this time, they’re coming for my job.

I just can’t quite get my big brain around the fact that my big brain is obsolete.

It’s going to take me a while — like a few posts — to work out the ramifications of that, to my own satisfaction.

If nothing else, if this does what I think it’s going to do, to “knowledge workers” generically, that’s got to be nothing but bad news for the real estate market here in Northern Virginia.  Pile on a dip in Federal employment, and, as I live here, I should pay attention to what’s happening with AI.

Even though I’d much rather not.

 


2: My garden is a mess

Yonder it sits, as of late fall of last year (left), and as of about 5 minutes ago (right).

In theory, this should be some sort of planned operation.  E.g., I want to grow such-and-such, in this-and-so quantity.  And so on.

In practice, I can’t even get that far.

Instead, this has turned into a game of fixing the worst errors, then seeing what’s left.

First, I need to get the sun-rotting plastic out of my garden, and disposed of.  But, as I (intentionally!) made the raised beds by recycling plastic coroplast campaign signs, removing those plastic sides effectively destroys all the existing raised beds. 

But, second, I always intended these beds to be temporary, and, ultimately, I figured the dirt would fill some of the worst “valleys” in my back yard.  So that’s what I’m doing — dismembering the side-less corpses of these raised beds and using the dirt to fill the largest and most annoying valleys in my lawn.

(These “valleys” are the aftermath of the installation of the ground loop for the ground source heat pump, and they continue to sink, ever-so-gently, 20 years after that was installed.  It really does not surprise me that this method (parallel trenches 6′ deep) seems relatively rarely used, compared to drilling a vertical well for the ground loop.  I already shoveled 10 tons of dirt trying to fill those valleys the first time.)

Third, I’m re-using the concrete corner blocks from the defunct low beds to build fewer, taller, better-placed raised beds.  I don’t actually want the resulting raised beds, but they are a place to store the concrete corner blocks, and most importantly, to store some of the soil that’s in the former plastic-sided beds.

Interesting calculation there. When I started these beds, I brought in 10 cubic yards of 50/50 mixed topsoil and compost.  And now, when I do the arithmetic on what’s left (bed dimensions x bed depth = volume of soil in bed), come up with about 5 cubic yards.  Which is just about exactly what I ought to have, if all the organic matter (the compost) in the original mix has rotted and so returned to being C02.  The upshot being that, at a density of about a ton per cubic yard, I’d have to shovel 5 tons of dirt, to get rid of these beds.  Not clear I’m up to that task any more.   Not clear that I’m not.

So, as stupid as it was to have to move a raised bed once, I am, in effect, moving them twice.  But the second time is largely to get rid of their dirt.  It’s a planned-life-cycle kind of thing.

And the new garden plan, such as it is, involves growing more stuff that neither the deer nor the bugs want to eat. But that my wife and I do.

That’s a very short list of crops.  That’s about as far as I’ve gotten on my garden plan for 2025.


3: Bee hotels, the final chapter begins

I am putting up my native (mason, orchard) bee hotels for the last time.  Mine are bundles of 6″ (or so) bamboo tubes, with smooth-cut ends (cut while green, or commercial pre-sanded cutoffs), with inside diameter around 3/8″ inch.  Above, I’m using Virginia clay to seal off one end of each tube.  When I have those sealed and dry to my satisfaction, those bundles of nesting tubes will be hung securely over the site of the emergence box (Post G25-001), ready for spring to commence.  And for the female mason bees to use at their convenience.  Next spring, the (now filled, hopefully) bundles of nesting tubes will have to be taken down and placed in next year’s bee emergence box.

Post G25-001: Finishing off my mason bee hotel duties

 

I have a small back-yard vegetable garden.  I’ve tried to keep that garden attractive to bees.  Partly, that’s for pollination.  Partly, that’s a good way to avoid using the worst and most persistent pesticides.

This post explains why I’m not going to be putting out a “bee hotel” in my garden this year.

Not only do these bees do nothing for my garden, I’m not sure I’m doing them any favors by providing such a large number of nesting sites.


Two years ago, I bought a little bee hotel at Home Depot.  In theory, this array of narrow, closed-ended tubes provides nesting sites for local native and solitary bees, e.g., mason bees, orchard bees.  (But not social bees, like honey bees or bumble bees.)

And, sure enough, about half the nesting tubes in that Home Depot bee hotel ended up filled, the first year I hung that up.  As shown at the left.

(I now know that this is a terrible bee hotel design and I would never buy it again.  The tubes are too short (4″), which apparently leads to an excess of male over female bees.  And they’re glued in place, and so cannot be replaced annually with clean nesting tubes, as everyone advises.)

Regardless, the picture above bodes good luck to this location, w/r/t/ mason bees.  A lot of people hang one of these up and get nothing, at least for a year or two.  But I followed all the directions, and hung that securely, a few feet off the ground, in a sheltered location that gets morning sun, with plenty of flowering plants nearby, and a nearby source of mud for the bees to use.  (That last one courtesy of some slightly leaky rainwater barrels.)

Following standard advice, I took that bee hotel down for the winter and left it in an unheated building.


Then I killed my overwintering mason bees.

I killed them with kindness.

My unheated outbuilding must have been just a touch warmer than the surrounding area.  In any case, by all the signs — average daytime temperature, extent of blooming flowers —  my bees emerged early, as explained in Post G24-004.  Just as the crocuses were starting to bloom.

If that didn’t kill them outright — from the low temperatures and lack of blooming plants for food — then it almost surely prevented them from reproducing.   Again, as explained in Post G24-004.

The moral of that story is, resist the urge to shelter your overwintering bees.  Let them freeze along with everything else.


 

One year ago, for my second attempt, I made my own bee hotels.  I used 6″ long bamboo tubes, cut from the green bamboo growing in my back yard (Post G23-015).  (Cutting them green gave them a smooth, splinter-free finish that did not require (e.g.) sanding.  Apparently, you don’t want to leave rough edges on these tubes, or they’ll cut up the bees’ wings.)

( You will see mentions of a lot of plants whose stems can, in theory, be used for bee nesting tubes.  I tried growing a few (e.g., poke weed), but I learned the hard way that, as with bamboo, your only realistic option is to harvest the material green, and immediately cut it to length.  If you wait until spring to go looking for some, all those hollow stems will be weathered and brittle, and you won’t be able to get nice smoothly-cut 6″ pieces from them.)

I closed off one end of each tube with some mud.

Locally-sourced.

Then bundled a handful of such tubes together with wire ties (and later, jute twine).

And hung up my nice new bee hotels, under the eaves of my back porch.

These were an even bigger hit with local mason bees.  As you can see at the left, almost all the nesting tubes were filled. Only a handful of empty tubes are left, and by eye, these seem to be too large for my local mason bees to want to use them.  (Bees are quite picky about what size of nesting tube they will use.)

Similarly, I made and hung one more bee hotel with much smaller-diameter tubes.  This would have been attractive to smaller “leaf cutter” bees that might be present in my area, mid-summer.  But I got no takers for those smaller tubes — that 4th bee hotel remained completely empty.


This year, I put those filled bee hotels into a “bee emergence box”.

This is just a dark box with some holes cut out of the sides, level with the bottom of the box, as shown, left.  (Level because the newly-emerged bees don’t fly out of the box, they crawl to the opening and hang out there for a while before dispersing.  That, according to the University of Utah extension service (Google link to .pdf).

Exactly why I need to supply a bee emergence box seems subject to some uncertainty.  Some experts say its to “avoid predators”.  (I assume the newly-emerged bees are fairly helpless.)  Some say the box must be place directly next to new bee hotels (with fresh nesting tubes) and should not be moved, not even a matter of inches.  Some say that the box allows female bees to find their way back to this location, as they can smell the old cocoons, but the box keeps them from re-using the old nesting tubes.

In short, all experts agree this step is good.  But exactly why it’s good, and what purpose this serves, seems unclear.  Somewhat folklore-ish.  (And clearly related to the naughty bits bee reproduction in some fashion, possibly explaining reticence on this subject.  But everybody agrees that such a box is a good idea.)

In any case, below are my home-made bamboo bee hotels, carefully and gently placed in my simple emergence box, before I closed and sealed the lid.

FWIW, one bamboo tube had a little tiny perfectly round hole drilled in it.  I’m pretty sure that was an instance of parasitic wasp predation, so I removed that one nesting tube as I placed these in the emergence box.

Apparently, the point of all the darkness is so that the only light entering the box is from the holes that I want the bees to use, to exit the box.  And, because this sits in a sheltered location (under the eaves of my porch), I’ve done the easiest thing and made the release box out of cardboard.  (Interestingly, I found scant details on release boxes, as if such details hardly mattered.)


Why I’m not putting out multiple bee hotels again this year.

First, these bees do my garden no good whatsoever.  These orchard or mason bees will have come and gone long before anything in my garden is blooming.  If I had an orchard, with lots of early-spring fruit blossoms, encouraging a local population of orchard bees would be a good idea.  But as it stands, these bees will have emerged, mated, and died a month before anything in my garden is blooming.

These are not the bees you’re looking for.  … Move along.

Second, it’s not clear that I’m doing them any good, either.  Mainly, it’s not clear that nesting sites are the limiting factor for my local mason bee population.  There really isn’t all that much around here blooming in late March.  And so, I wonder if in effect, I may be raising bees, simply to have them die off soon after they emerge, because there’s no link between the number of bee hotel tubes that I provide, and the size of the local early-spring flowering plant supply.

I found no guidance whatsoever on “right-sizing” a mason bee hotel, to match the resources available in the surrounding area.


Conclusion

 

There’s not a lot to providing nesting sites for solitary bees.  You just have to obey a few simple rules.

The nesting tubes should be about 6″ long, for the most common mason bees.  The tubes need to be of about the right diameter for the bees you are trying to attract.  In my case, maybe 1/4th to 3/8ths of an inch.  If you use natural materials, you’ll get some variation in diameter anyway.  One end of each tube needs to be closed off.  (I did that with mud.) You need to have them set up so that you can either throw them away once they have been used, or sterilize them (e.g., soak in bleach) for re-use.

And you need to move your bee hotels (or the contents thereof) to a release box the next spring.  That’s just a box with holes at floor level, so that the emerging bees will see the light and crawl out into the outdoors.  That way, they can emerge, but they aren’t able to find their way back in again and re-use the old nesting tubes.

But, be aware that when they say you should try to attract bees to your vegetable garden, they didn’t mean mason bees.  These guys are up and about way too early in the year to do my garden any good.   They’ll have lived out their lives weeks before the first pea blossoms open up.

My upshot is that I need to let this box sit around for, at most, a couple of months.  Then I can throw the whole thing away.  I guess I’ll continue to put up bee hotels until I’ve used up my stock of six-inch bamboo tubes.  But I’m not seeing any benefit to making this a permanent part of my garden.

Addendum

I relented.  These are this year’s bee hotels, pre-mud.  I took the best from my stash of potential bee nesting tubes.  And tossed the rest.

My final thought on the emergence box is that mine is entirely in the shade.  (Facing east-ish, on the north-ish side of the house, though I think that’s not very relevant.)

The point is, cool.  Living in Zone 7b, with little nearby in the way of flowering fruit trees, I think the later my bees waken, the better.  Within reason.  There will be more around to eat, I think.  In any case, no direct solar heating — no direct sunlight — is consistent with this year’s approach of not sheltering the bee hotels in winter.  These bees are going to have to live in the ambient air.  They need to be in sync with ambient air temperatures.

But I can see where, in a more northerly climate, you might make the other call, and at this time of year, that if a bit of extra heat means having your bees up and about a little earlier, then that’s a good thing.

In both cases, I’m guessing that you up the odds of bee survival by trying to ensure that their emergence coincides with lots of local blooms, within what the bees themselves can tolerate.

Anyway, crocuses alone make slim pickings for orchard bees.  My observation, based on my unfortunate experience last year.  So perhaps I am erring on the side of caution.

Or, in this case, shade.

Post G24-014: Creeping Charlie puller and other garden items.

 

Creeping Charley is a weed, also know as ground ivy.  When mature, it forms masses of thin vines (stolons), loosely rooted to the ground.  My “puller” is a bow rake paired with a paint roller.  It’s crude, but this allowed me to pull masses of Creeping Charlie out of a garden bed that I was preparing, without having to stoop over and pull it by hand.  Details are below.

Continue reading Post G24-014: Creeping Charlie puller and other garden items.

Post G24-004: Advice on sheltering your bee hotel for the winter.

 

My advice:  Don’t shelter your bee hotel for the winter.  Let it freeze along with everything else.  This post explains why.


Early bee emergence

Last year, for the first time, I hung up a bee hotel.  This is a set of nesting tubes designed to make it easier for solitary/native bees, such as mason bees, to reproduce.  It seemed to be quite successful, per the picture below.  Ultimately I ended up with about 15 nesting tubes filled.

I left that up through the summer and fall, and, per common internet advice, moved it to a sheltered location once winter set in.  In this case, I moved it to the inside of a detached, totally unheated garage.

Moving a bee hotel to a sheltered location, for the winter, is probably not a good idea.  Despite that being widely suggested by seeming experts.  That’s because if your sheltered area is even a little warmer than the outdoors, I think it entices the bees to emerge too early.

That’s what appears to have happened this year.  For my particular Home Depot bee hotel, the nesting tubes that were filled by mason bees last spring …

… are all now empty.

Consistent with that, my wife noticed some bees on her crocuses this morning.  Which was odd enough to stand out.  Because, among other things, not much is blooming right now except crocus and daffodil.  And it’s not all that warm out yet.  The upshot is that it seems a little early to be seeing bees out and about.

I’m betting that those were “my” bees.  And I’m betting that I did them no favors by (inadvertently) waking them up too early, this year.  If I put up a bee hotel again this year, I’m just going to leave it alone.  I’m now of the opinion that  bees ought to overwinter at exactly the temperatures they’ll face out-of-doors.


Like Tinder, but with only 15 people using it.

Experts say that mason bees should emerge when blossoms are open, and daytime temperatures consistently reach 55F (reference).

By those benchmarks — blooms and temperature — my bees are at least three weeks too early. That’s based on these observations.

Blossoms:  Slim pickings.  At present, only the crocuses, daffodils, and maybe a scattered other few species blooming.  There are a few cherry trees here and there, in this area, in blossom.  For reference, the earliest recorded peak bloom date for the national cherry trees is March 15, with April 1 being a typical date (reference March 15 to the National Park Service).  Separately, a harbinger of spring in many areas is forsythia, but our forsythia isn’t even close to blooming yet.

Temperatures:  Still too cold.  We’ve had a couple of days where the high exceeded 55F, but those are still few and far between.  We are not consistently 55F and higher.  But we’re closing in on that.

Source:  Weather underground. 

And based on our historical weather averages, you wouldn’t expect consistent 55F and higher days for another two-three weeks or so.

Source:  Analysis of NOAA weather data for Dulles Airport (Sterling, VA).

All of that, plus my experience last year, tells me that my little batch of bees emerged the better part of a month too early.  Call it three weeks, minimum.

Finally, these bees don’t live very long.  They emerge, eat, mate, and die within a span of a few weeks.  They’re now out of sync with their species in general, and they’re going to be dead before the rest of the local mason bee population emerges.  So, if they all survive, their procreation will be as described in the section title.


Conclusion

I’m not a bee expert, but I’ve spent a lot of time observing the habits of bugs, since I took up gardening during the pandemic.  The one universal rule is that everything in the garden — plants and bugs alike — operates on temperature, and on degree-days.

By keeping this bee hotel in an unheated garage, I kept it warmer than the ambient outdoor temperatures.  I suspect that, one way or the other, this caused my bees to emerge earlier than is optimal, for their species.

If I do this again this year, I’m going to leave the bee hotel outside all winter.  The bee larvae may not much like the cold, but they need to stay in sync with outdoor temperatures, in order to emerge at the right time.

Source;  All the pictures for this post are from Gencraft.com AI, with the prompt of “a bee, wearing a stocking cap and scarf”.

Addendum:  To bee, or not.

Edit:  In the end, I gave it another go, doing it better this time, as explained in Post #G24-008.  This year, my bee hotels are ugly, but properly constructed (closed-ended tubes roughly 6″ long), as shown above.  Well over half the tubes are now filled, as of this writing (4/22/2024).  I’m just going to leave them be until its time to take them down and put them in an emergence box next spring.

Original post follows.

Am I going to put up bee hotel this year?  Not sure, but at this point, I’d say, no not.  Probably not going to put up another bee hotel this year.  For the following reasons.

First, these bees don’t pollinate my garden.  They’re out and about early in the year, and they are gone by the time my garden crops or flowers need pollination.  So when you hear about “attracting bees to your garden to get better yields”, they ain’t talking about mason bees.  The earliest-blossoming food I grow is peas, and my recollection is that mason bees do their thing well before (e.g.) the peas blossom.  Apparently they are good for orchards.  Which would make sense, as fruit trees blossom early.  (And mason bees are orchard bees, or orchard bees are mason bees, or something, I’m not entirely sure.  I don’t have an orchard.)

Second, I’m trying to grow the kinds of plants that (the internet tells me) make good natural nesting sites for these bees.  But that whole enterprise is looking a bit sketchy at the moment.  I’ve started down that path, by not mowing my wildflower beds yet.

You’d think, well, that’s got to be dead easy, just grow some plants and leave them. Just don’t mow.

But its not that simple.

Mason bees need medium-sized hollow stalks to nest in.  (Or equivalent.)  That seems right by my experience so far.  Sturdy annuals will sometimes leave behind big, ugly stems.  Looks about the right size.

But that’s the point where anything ceases to be easy.

In a nutshell, you have to keep them for two years, they’re ugly, they get in the way, and you have to defend them from the deer.  I’m not going to go through the details.  I can boil it down to this.

Do I really want to use my time and attention to try to protect some ugly weed stalks from ravenous end-of-winter marauding deer?  For a couple of years, yet (the literal same batch of stalks, I mean.)  And somehow work around them, while prepping the beds for this year’s flowers.  And in the end, really have no clue whether they are effective or not.

I have a lot of sunk cost in this whole bee-hotel thing, not in the sense of buying the Home Depot wooden bee hotel, but mostly in the time and effort gathering and cutting bamboo, in anticipation of annul replacement of the nesting tubes in that hotel.

In addition, rehabbing that Home Depot hotel for re-use could be a fair bit of work.  I should replace the bamboo nesting tubes each year.  This year — with the off-the-shelf unit — that means breaking the existing glued-in tubes out first.

I think I’ll see how hard the rehab is, first, then decide on next steps after that.

But as of right now, I’m not seeing a huge benefit to anybody or anything in being a mason bee hotel keeper for another year.  I should let them find their equilibrium vis-a-vis the local flora.  Might tweak the flora to try to help them out, if I can figure out how to do it.  But I think I’m going to punt on maintaining a manufactured bee hotel.

Post G23-013: Bee hotel success, Part 1

Edit 5/19/2024:  This year, I made my own bee hotels, and those worked out a lot better than the off-the-shelf bee hotel that I discuss in this post.  See Post G24-014 for this year’s bee hotel results, and Post G24-008 for construction details, such as they are.

Original post follows:

I try to maintain a reasonably bee-friendly property, out here in the wilds of Northern Virginia.

It’s not just that I need them to pollinate my vegetable garden. Or that bumblebees do, in fact, sleep in squash blossoms (aw!).  Or that the hum of bees at work in my garden marked the never-to-be-repeated peak of mid-pandemic suburban quiet (Post #G11).

It’s more bee-as-coal-mine-canary. If I’m doing something in the yard or garden that’s likely to be killing off my bees, odds are I shouldn’t be doing that.  It’s a quick way to rule out some environmentally stupid behavior.

In any case, I’ve had a couple of bee hotels (native bee nesting boxes) kicking around my yard for a few years now.  Shown above.  But those were never very successful.  It took years to get the first bees to use them.  And I might get a one or two tubes filled, per year.  There are clear exit holes on some tubes, so some new bees were produced.

But not a big hit, over all.

This year, on a whim, I bought a different model of bee hotel, at my local Home Depot.  The Home Depot mason bee box is already working vastly better than the previous model.  It’s been up a few days and I already have more tubes filled than I got in the first few years of the other model.  In short, my bees love this new bee hotel.

Now that I’m finally doing something right, I’d like to keep that going.  In a radical and very un-guy-like step, I actually read the directions.    And — surprise — I’ve been clueless as to how these things actually work. 

But now that I know, I realize this new bee motel is a fundamentally terrible design.  Not for what you can see — that part’s OK.  And, as noted, it’s definitely attracting bees.  The problem is that those bamboo tubes are permanently attached.  As discussed below, that’s a no-no.  You want nice clean new nesting tubes each year.  And that means that, unless I tear it apart next year, this lovely little bee hotel is a single-use disposable item.

So this post is going to summarize everything I think I learned about mason bee nest boxes (“bee hotels”).  And about the difficulty of making smooth-ended splinter-free replacement tubes for this, from bamboo I have on hand.


Three-minute tutorial:  Bee hotel or roach motel?

Key point: For best results, you need two bee hotels (or equivalent) for every site at which you wish to maintain a bee hotel.

You ideally want the female bees to use clean, new nesting materials each year.  The use of new (or carefully sanitized) nesting tubes each year minimizes the presence of diseases and parasites in the nest.  If you don’t keep the premises clean, your bee hotel can end up as the bee equivalent of a roach motel.  With poor enough conditions, the bees check in, but they never check out.  Your bee hotel becomes a catch-and-kill trap. 

The problem is that each spring, some bees are ready to check into your bee hotel before your existing guests have checked out.  Some are ready to lay their eggs before others have emerged from their cocoons.  The reason for this chaos is that these bees are quite short-lived.  The emerge, mate, forage for food, lay their eggs, and die, all in the course of a few weeks in the spring.

The solution is to put last year’s bee hotel (or, at least, the nesting tubes) aside in an “emergence box”, to give the bees time to emerge from their cocoons.  At the same time, you need fresh, new nesting tubes nearby, for the emerging bees to lay the next generation of eggs.  An emergence box is just an opaque weather-protected box with a small opening.  This allows the newly-emerged bees to exit, but prevents bees outside the box from seeing (and therefore attempting to re-use) the old nesting tubes.

No matter how you cut it, you would ideally have two sets of nesting tubes in rotation at each bee hotel site.  One set of clean, new tubes, for this year’s eggs.  And last year’s tubes, from which bees continue to emerge.  You want to keep the emergence box with last year’s nesting tubes near your new bee hotel, because, as noted above, the bees get right down to business as soon as they emerge.


Here are my five Ws for bee hotels.

Who?  These bee hotels provide nesting places for some species of solitary bees, that is, bees that don’t form big communal hives.  Mainly, that means these are NOT for honeybees.  The bees that use these devices are typically referred to as “native bees”, but that’s imprecise.  For one thing, bumblebees are typically native bees, but those are ground-nesting bees, and won’t use these tube-type bee hotels.  Your primary target bee is a “mason bee”, so called exactly because they build those little mud walls at the end of the nesting tube where they’ve laid their eggs.

What?   A bee hotel provides tubular structures into which a mason (or similar) bee lays eggs.  The bee lays a series of eggs in the tube, providing each with food, separating them with mud walls, and capping off the tube with more mud.  Over the course of a year (in some cases, two years), each egg hatches into a larvum (worm), eats the food that its mother left for it, pupates (cocoons itself), and eventually emerges from that cocoon, the subsequent year, as a bee.

When?  The eggs are laid in spring.  The eggs hatch/larvae emerge in summer.  They cocoon in the fall.  And they re-emerge as bees the next spring/summer.  (In some areas, there are species that spend two years in the cocoon, but I’m not sure how relevant that is to most places.)

Place your bee hotel outside in the spring.  It appears to be fairly important not to disturb this during summer, as the larvae are delicate.  That means you attach it to something solid in the spring, so it doesn’t shake around, and you leave it alone.  The larvae pupate in fall.  At that point — late fall, early winter — they are tough enough to be moved.  Place the bee hotel in a sheltered, unheated location (such as an unheated shed).  Then, next spring, place the bee hotel (or the tubes from it) in an “emergence box”, move them back outside, and let the bees emerge as the weather warms. Google “emergence box”, but it’s basically a sheltered box with a hole in it, to let the hatched bees escape.

Some experts “harvest” the cocoons as an extra sanitation measure.  They break open the nesting tubes, remove and possibly clean the cocoons exteriors, and place the cocoons in fresh material for eventual hatch-out in the spring.   The claimed advantage of this is that it separates the bees from various parasites that may linger in the nesting tubes and this allows them to emerge from overwintering parasite-free.  If you are going to do that, you need to use relatively fragile nesting tubes (paper liners, reeds) that allow the cocoons to be removed undamaged, and not sturdy ones such as bamboo tubes shown above.

As of this writing, it’s not clear to me how much of an advantage you gain by harvesting cocoons, or what evidence basis there is for it.  The only obvious advantage is that if certain fungal diseases are present in the nest, you’ll see them if you harvest the cocoon.  As I plan to use all-new materials each year, I’m not sure that’s much of a concern to me.

Where?  These bee nests ought to be protected from rain, protected from getting cooked in the afternoon sun, and so on.  he most common advice is to locate them to catch morning (but not afternoon) sunlight.  They need to be firmly attached to something substantial because the larvae are delicate and don’t want to be tossed about.  In plain sight, so the bees can find it.  And near a ready source of mud.  Because bees need mud to cap off their egg cells.

Upshot:  Facing east-ish, under eaves if possible, firmly attached to something, near water or mud, maybe 5′ off the ground, and plainly visible.

Why and how? Different bee species want different sized tubes.  So from the get-go, a rack of identical tubes limits the species that can use that particular hotel.   The tubes need to be closed off at the back, in some fashion.  The tubes need to be sturdy enough to keep out various bee predators.  Paper straws alone, for example, appear to be frowned upon, thought to be too fragile to keep out certain types of bee predators.  In rare cases, you need to put hardware cloth across the front to keep birds from pecking out the larvae.  That’s only necessary if you wake up one morning and all the previously-filled tubes appear empty.

The simple upshot of all this is:

  • Each Spring, put last year’s nest out in an emergence box.
  • Nearby, place a clean, new nest out to attract bees.
  • Each Fall, refurbish last year’s nest, to be placed out the next spring.