>>    I have been told year after year to reverse the brood chambers every 7 to
>> 10 days.  This, I am told prevents congestion in the hive.
 
>... you have to make sure
>the first reverse is after the spring weather is *truly* settled.
 
TRULY settled indeed.  Yes, Nick this deserves some emphasis!   I have made
the mistake of becoming a little too anxious (one year after a long winter)
and starting brood nest reversals on a warm day in mid-April.  You know,
one of those balmy, perhaps unseasonably warm WONDERFUL days that come and
make the bees (and bee-enthusiasts) so active.
 
Well, suffice it to say that i did my reversals in one yard of a dozen
colonies that day, and thought i had gotten a jump on the season.  The
colonies were expanding and healthy.  Of course, a cold snap followed
immediately.  I figured, great, glad i got that much done while the weather
was nice!  Next time i inspected those colonies, many of them were
basically starting over with pitifully small brood nests as my "management"
had destroyed the integrity of their nests and they couldn't cover the
brood sufficiently in the cold.  Such a waste!  Since then i've tried to
wait until populations are larger and temperatures milder & more stable -
first week in May generally (upstate NY).  I just finished up this years'
reversing yesterday, in fact, and this is the longest i've ever had to wait
to reverse and spring clean.  We had snow last weekend and a couple of
freezing nights to boot.   Seems more like early April than mid-May