What lessons did you learn in 2019?
For me the list was long. Here are some of them:
Making Queens - I get more/larger queen cells if I remove the queen and some nurse bees from a strong hive, than if I remove a frame of eggs/brood to make a Nuc split.
Replacing queens - to be more proactive in replacing failing queens, rather than waiting for the bees to do it. I could have saved 2 hives if I'd done that.
Baiting and killing ants - helped a lot this year
Splits - I lost at least 20 split attempts this year. It took me 6 of them to realize that robbing was the main problem that I was having. I lost another 4 nucs before I started using robbing screens. I lost 2 due to a rain storm that blew the lids off nucs and rained them out - gotta put weights on the lids of new hives until they are strong enough to seal everything tightly. Ants, uexpected queen loss, and queens that failed to return from mating, accounted for the rest of the fails. Hopefully 2020 will see better results.
Robbing screens - I learned to make them, and use them. I really didn't get an increase in hives until I got this figured out. Both SS screen door replacement screen & #8 hardware cloth work well for this. I didn't get fancy - just cut a piece of screen, and used thumb-tacks to secure around the entrance. This also kept the YJ's at bay.
Goals - I entered 2019 with 3 viable hives and a plan [that didn't work] to make a honey crop and end the year with 20 hives via splits. I should have had smaller goals. I ended the year with 9 hives instead. ... the good news is that I sold all the honey I harvested within 24 hrs of harvest, for top dollar. I kept 2 gallons for our family - that wasn't enough
Pollen - I learned to harvest it. None of it left the house - we ate it all
Honey harvest - bees consume more honey in the summer/fall dearth than I anticipated. I ended up feeding 4 hives in Sept/Oct to get them thru the fall. I definitely need to leave them more stores to avoid feeding.
Nuc transitions - I waited too long to transition hives from 5 frame Nucs over to 8 frame hives. This resulted in transitioning very strong, and very unhappy hives - lots of stings happen then. Me thinks I'll move them over sooner this year.
... this is just some of the things I learned ... it was a fun year of beekeeping!