Pacific Coast Iris - best time to transplant?

Jane McGary
Mon, 04 Feb 2013 10:12:40 PST
If the Pacific Coast irises sold in spring can't be carried through 
the summer in southern California, you can buy potted ones shipped in 
fall from Wild Ginger Farm <> . I bought and 
planted a dozen of them this past fall and expect them to do well. 
The previous year, I bought a few from Aitken's Salmon Creek Nursery, 
but they were shipped bare-root in October and, although planted 
properly the day received, not a single one survived. I've been 
growing PCIs for many years and have also seen a lot of them in the 
wild, including I. tenax, native to my former garden.

Another good strategy for establishing these plants, if you don't 
insist on named cultivars, is growing them from seed. Seeds of both 
species and hybrids are distributed by SIGNA and I think by a section 
of the American Iris Society devoted to PCIs; Emma Elliott, a member 
of the PBS as well, can no doubt provide more information about the 
seed exchanges as she runs one of them. Many years ago I got a packet 
of seeds through SIGNA that had been donated by one of the top 
growers, and was able to raise some beautiful plants that are still 
flourishing at my old garden. Emma has propagated some of them in 
their nursery, and this October I dug divisions and potted them. I'll 
grow them on in pots until next fall and then plant them out. The 
seeds, planted preferably in fall, germinate quickly (unlike some 
other kinds of irises) and can be moved into 4-inch pots when they 
have two or three leaves, grown on for a year, and put into the 
garden while still quite small. I've even planted tiny seedlings 
directly outdoors and they did fine -- better than divisions of 
mature plants. (Garden seed may not always give such good results, 
since PCIs can hybridize with one group of Siberian irises; I raised 
one batch of seedlings that appeared to include "Cal-Sibes" and some 
of them were unattractive in flower.)

I read somewhere that the Ghio hybrid PCIs, discussed by several 
correspondents, often have I. munzii in their ancestry. This species, 
which has particularly good blue pigment, is rather tender and also 
quite large, so perhaps those of us in cooler climates should look 
elsewhere for suitable garden cultivars. My favorites are those that 
involve I. douglasiana, because they're hardy and have excellent 
broad, dark, glossy evergreen foliage that is a design asset when the 
fleeting bloom season is over.

Regarding Iris unguicularis, which another correspondent suggested 
should be purchased in a pot, I got one of the varieties I grow from 
England as a bare rhizome and had no difficulty establishing it in 
the bulb frame. Rhizomes moved to the new garden and planted in a 
raised bed in the open have taken well and are in flower. It probably 
depends on the time of year you move it.

Jane McGary
Portland, Oregon, USA

More information about the pbs mailing list