thank you for the acorn william.
the pots are haphazardly placed in the beds where i know they will be hit with the auto-sprinkler 3x a week. for awhile it was 2x then 1 time when we were in extreme drought conditions). however, to this auto sprinkle i hand water when i think the pots in those areas looked dry. not too much shade, my back garden is southwest facing. ( not true west but pretty close)
however i have another permanent pot collection, with about 15+ irises, which i hand water every few days....i check w/a water meter. scattered amongst these larger pots, i also have 10+ one gal. irises, waiting to find a home in the ground or waiting for a larger pot to be transferred. this sits up on a concrete deck and the deck retains heat from the day if the sun is out. not too much shade on this deck either.
moreover, in the front garden, where most of my in-ground collection lives is ne (not true east but...) and is about 10-20 degrees cooler than the back. the irises grow much better in the ground, but do not bloom as much as the ones in the large pots. there's more shade, and i've not experienced much bloom out here, but clumps are decidedly larger than back. (clumps range from about 6-10 rhizomes as opposed to 3-5 )
so, from this limited comparison william, it maybe the warmer the area the more frequent watering necessary. i have tried to deep water, but find this is a wasted resource.
my bloom out occurs mostly in the back, where the sun is relentless in the summer months of july, august, and the first half of september. perhaps, i may just have to water more than i have in the past?
i've noticed with these last prolonged rains (for s.d. county), the irises in general appearance seem a lot happier and healthier. but, have more snail/slug riddled leaves, and no bud sockets?
i may just be overly anxious, but i did see blooms in january through march blooms on many of my rebloomers last year and not so much in 2019. the only ones that did bloom early last year and this were: 'absolute cute', 'capt. thunderbolt', 'concertina' ( re), 'fall empire' (re), and yonkers.
by now i should be seeing more pregnant fans for the april bloom...so far none.