Salt-tolerant Pacific Iris, or Choosing Voles & Birds Over Cats

by Kathleen Sayce

Mowing the upper edge of the marsh along the Washington State U.S. coast on Memorial Weekend, I found a flowering iris growing among taller grasses. 

A saltwater-tolerant PCI in the upper salt marsh

Lest you think I was mowing native and/or sensitive salt marsh species, let me reassure you:  I was mowing ivy, gorse, and reed canary grass. The last is one of a group of big grasses with thuggish tendencies, and the first two are obnoxious weeds in many areas. These species grow along the upper edge of the salt marsh, and collectively tolerate salt water on the highest storm tides each winter. I dodged two native plants:  seawatch clumps (Angelica lucida, a tall carrot family wildflower) and edible thistle stems (Cirsium edule). 

Almost hidden in taller grasses, this PCI was a delightful surprise

This iris is a small, species-like Pacifica iris of unknown parentage which looks most like a PCI of unknown origin that I planted in the mid-1990s, though that plant has larger, wider petals and darker flowers.

Salt water covers this spot several times each winter on the highest storm tides—it grows in a saltwater inundation area. Iris tenax and I. douglasiana both live in salt spray zones along the coast. I will keep the taller grasses down around it, and see how long it lives here. The salt tolerance is a surprise. 

How did it get across the driveway and into the marsh? Voles are the probable suspects; they live abundant and prolific lives in the marsh and garden—and in our garage, cars, and occasionally, house. It is likely that a vole filled its cheeks with ripe iris seeds and dashed off across the driveway to stash them in the marsh.

Get a cat, you say. 

My reply:  I would rather have a garden with ground-nesting birds. 

There are two areas in the garden where Spotted Towhee and White-crown Sparrow nest. The adults pop out to complain when I mow nearby, and grow quite insistent if I weed too near nests, which tend to be under large clumps of Pacifica iris. Which of course means weeds grow unchecked in those areas for much of the summer, and that favors voles!