Regelia and Regeliocyclus irises
Jane McGary (Sat, 26 Nov 2011 16:21:05 PST)

I'm looking for information on the annual cycle of irises in the
Regelia section and their hybrids with Oncocyclus irises, known
sometimes as "Regeliocyclus." When I grew these in frames in large
clay pots, kept dry in summer, they did not make significant leaf
growth until late winter. Now I have them in a raised bed inside an
unheated bulb house, and some of them never really went dormant last
summer, even though not watered, and their leaves are almost full
size now. I don't like to see this, because I can't grow Onco irises,
which make early foliage growth that then succumbs to disease during
our humid winters. Did planting the rhizomes out allow them to reach
down so deep that they had some moisture throughout summer? (The bed
has a commercial woven groundcloth liner over native clay.) Is this
bad for them?

I saw whitefly on the leaves and placed sticky traps nearby, which
seems to have controlled them to a great extent, but I think I'd
better use a systemic insecticide on the plants too. I never had
aphids in the bulb frames at my former home, but it's considerably
colder and windier there, and also the insect population, including
predators, is much more numerous and presumably complete as an
ecosystem than what one finds in the suburbs. I thought of buying
ladybugs (lady beetles), but they are dormant in winter, and anyway
they'd probably just fly away through the hardware cloth walls of the
bulb house.

How do these irises behave for other growers?

Thanks,
Jane McGary
Portland, Oregon, USA