Pacific Coast Iris - best time to transplant?

Kathleen Sayce
Sun, 03 Feb 2013 12:25:52 PST

This is an excellent question. Successful transplanting is done when the PCI plant has active root growth, which tends to be fall-spring on the West Coast of North America. To check roots, dig away at the edge of the clump where you see a new shoot appearing; if the roots are white and firm, and 1/2 to more than 1 inch long, it's transplant time. 

Towards the north on the West Coast, this period starts a few weeks after rains begin, usually in October, and ends in April or May, and of course is suspended during freezing periods. 
The transplant period is compressed to the south, later in the fall, to late winter. I have noticed during wet summers that I can successfully move I. douglasiana in July, but think this success is due to excellent drainage (sand) and generally cool summer temperatures. 

Did you get your plants at Santa Barbara Botanic Garden? Sounds like they are very happy in your garden. I also have problems with grass, and just emptied a bed of PCI last summer, to leave it fallow as long as it takes to get the grass out, in this case, quack grass. I dug to 18 inches, and still have new grass shoots appearing six months later (argh). I'm contemplating both herbicides and steam. 


Kathleen Sayce
PNW Coast, WHZ 8, dryish cool summers & mild wet winters

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