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! 

What was your first flower?

Kathleen Sayce

There’s a theory that people who like plants and garden throughout their lives express that fascination at a very young age. It usually happens between ages 3 and 5, when we are avidly exploring the world. I know a birder who made that initial and lasting connection with another life form at age 2 (mallard duck), and wildlife biologists, ditto, ages 4 and 6 (rabbits and deer). 

A Pacifica Iris seedling in my garden, 2021

What was your first flower? Did that sense of connection change as you grew up?

I have a friend whose first fascinating organism was a pansy, at age 3. He saw a flowering pot at his grandparent’s house; his grandmother was a lifelong gardener. He picked it up, studied the plant, and was drawn in by the flower’s colors, complexity and petal shapes. He became a horticulturist, worked in well-known gardens and nurseries across the country, and now grows plants from all over the world, has a seedling garden where he grows dahlia crosses, and does amazing flower arrangements. Flowers became his life at age 3. 

For me, the fatally attractive flower was an iris, age 2. There was the snaky rhizome, creeping across the surface of the ground. It was so un-plant-like! The flower was stunning: standards and falls and shaggy beards in a fascinating asymmetry. The light shining through the purple petals was amazing. And the shape of the flower buds was simply entrancing. 

I now know this was a purple-flowered tall bearded iris, but to my young self, it opened up a view into the other half of the living world—plants. 

I wanted to weed out the grasses and study how it grew, but my mom disagreed. She said the flowers were old fashioned; she planned a vegetable garden in that spot. We had just moved to a new house, and the next year she did indeed put in a vegetable garden with pole peas and beans, radishes, carrots, zucchini, and an asparagus patch. I promptly began checking radishes every few days to see how the root developed into a round edible vegetable, but that’s another story. Suffice it to say my parents were not pleased to find the radish seedlings vanishing day by day. 

My love of that first iris flower morphed into a fascination with all things chlorophyllous, which led me into lichens, mosses, kelps, wildflowers, and eventually into Pacifica Iris. 

What’s your story?

Update: Iris douglasiana at Atlanta Botanical Garden

by Kathleen Sayce

Iris douglasiana seedling at Atlanta Botanical Garden

In January 2022, Raleigh Wasser, Horticulture Manager, Atlanta Botanical Garden, sent me a update about their lone Iris douglasiana plant, which is growing in an alpine style bed with excellent drainage. After reading Wasser’s article about the botanical garden’s alpine-style bed in the Rock Garden Quarterly, I wrote a blog post about it in June 2021. 

World of Irises readers may recall that this plant flowered last spring. The plant went on to produce a pod with about ten seeds last summer. Botanic garden staff collected the seeds and sowed them. 

Raleigh’s update takes up the narrative: “We germinated a douglasiana seed! Just put it in some potting mix and left it in a corner of our greenhouse. Of about 10 seeds this is the only one that germinated.”

I suggested she put that pot outside as winter ends, and perhaps other seeds might germinate. Seeds of Pacific Coast native irises may take one to three years to decide to sprout, even from the same pod. However, getting even one seed to germinate and thrive is wonderful! 

Reminder: Seeds of Pacific Coast native irises do not like to germinate in warm, humid conditions. These seeds are fine outside in the snow and rain, so long as it is not too cold. Zone 7, -10°F is about their lower limit. I suspect the Atlantic Botanic Garden greenhouse where the seedling germinated is cool, not warm. 

This extraordinary Pacific Coast iris and its offspring continue to deliver surprises in its Atlanta, Georgia home.

Willapa Refuge’s Wild Lawn: First Spring

Kathleen Sayce, June 18, 2021

A seedling PCI shows its complex parentage

It’s been eight months since the wild lawn was planted at the new office for Willapa National Wildlife Refuge, and Pacifica irises bloomed in their first spring. I took a few photos when I visited the lawn in April and June, while Program Manager Jackie Ferrier photographed almost every iris that flowered. 

We expect a bigger display of flowers next year as the wild lawn settles in. 

A variety of Pacifica iris grow in the lawn, including I. douglasiana, I. tenax, and seedlings from PCI hybrids. The plan is to let all the plants set seed, and scatter the seed around in late summer. We will also be planting more areas in coming years as the blackberries and other woody shrubs are suppressed around the visitors center and staff offices. One annual fall mowing is planned. Without mowing, woody shrubs and trees would soon (very soon!) take over the entire area. 

Looking NW in early spring to Willapa Bay

The grasses that provide a backdrop to the wildflowers are fescues, including Roemer’s and red fescue, and a low growing fescue mix. A combination of fescue plugs and seeds were used. This is important, because the grasses that grew here historically included reed canary grass, velvet grass and orchard grass, all too large and too dense for irises to thrive with them. 

Thrift in meadow

Iris tenax seedling

Other wildflowers include strawberry, springbank clover, yarrow, pearly everlasting and thrift. 

A new compost facility is selling compost by the truckload, so the next sections of the wild lawn will get a top dressing of compost to boost nutrient retention in winter, and water retention in summer. In these sections the compost will be tilled into the upper few inches. In the original section, we will top dress the lawn with an inch or so of compost next fall. 

I. douglasiana

PCI Mission Santa Cruz

This location was formerly a cattle ranch homesite, and there are thousands of daffodils growing throughout the area. The daffodils were retained as legacy plants, and also put on a nice display last spring. 

This fall we will add more wildflowers, including shooting-stars, common camas, checkermallow, chocolate lily, blue-eyed grass, and of course, more irises. 

If anyone wants a plant list, please contact me by email and I will send you the plant-list-in-progress. 

Wild Pacifica Irises in Northern California

By Kathleen Sayce, with Photos by Tom Lofken

Tom lives in northern California, and took the photos for this essay over several years. 

Iris douglasiana

First up is a tough, widely distributed iris, Iris douglasiana, which grows naturally from southern Oregon to southern California near Santa Barbara. Tom took this image at Point Reyes, where an extensive purple-flowered population can be found. 

Yellow, white, rose pink and lavender flowers are also common for this species, which produces some of the toughest plants the Pacifica Iris group for gardens. 

Iris hartwegii ssp. pinetorum

Next, from the Sierra Nevada foothills, Iris hartwegii ssp. pinetorum.  This subspecies may eventually be re-elevated to species status as its genetics are distinctly different from other subspecies. I. h. pinetorum grows in the California Coast Ranges and Sierra Nevada, where it prefers flats in open pine forests. 

[Readers may recall I grow Iris hartwegii ssp. australis in my garden; this subspecies grows only in the Transverse Ranges of southern California.]

Iris macrosiphon

Iris macrosiphon is widespread in northern California and also varies in flower color. It is found around the Bay Area in the mountains, and north in the Coast Range to the Klamath Range, northern California. I. macrosiphon has a very long ovary tube—the ‘stem’ between the ovary and the flower petals. The leafy bracts in the photo cover the long tube. The ovary sits just above the base of the bracts and well below the flower. 

Iris tenuissima ssp. tenuissima 

Iris tenuissima ssp. tenuissima is found in northern California, in the Sierra Nevada foothills and Coast Range. Flowers are pale yellow to white, with dark maroon to red veins. 

Iris bracteata

Iris bracteata grows in northern California and southern Oregon, has pale yellow flowers with dark veins, often with a reddish color to the perianth tubed, and is typically found in yellow pine forests above 1,000 ft elevation. This photo is from Josephine County, Oregon. 

Iris chrysophylla

Iris chrysophylla has strikingly long stigmatic crests, those petal bits that stick up on the style arms.  These look like two long teeth (a vampire’s long canines), in an otherwise typical wild Pacifica Iris flower. Flowers are usually pale yellow, can be white, and are veined burgundy on the falls. This species grows in open coniferous forests in northern California and southern Oregon. 

Iris thompsonii

Tom looked for the golden iris, Iris innominata in northern California, which grows wild only in southern Oregon. It has lovely yellow (dark gold to pale yellow) flowers. 

Instead, he found a hybrid of Iris thompsonii, possibly crossed with I. bracteata or I. tenuissima, showing pale petals, strong veining, and growing in densely floriferous clumps. 

Like I. innominata, I. thompsonii is deciduous, with leaves dying back to the ground each winter. 

Other species that share this trait are Iris tenax and I. hartwegii. 

Taxonomy:

For current taxonomy, refer to The Jepson Manual, 2nd edition, for a key to Irises species in this subsection. All taxa except Iris tenax ssp. tenax and ssp. gormanii are covered in this key.  

Older taxonomy references include Victor Cohen, A field guide to species, and Lee Lentz’s books. The latter three publications are available to download by members of the Society for Pacific Coast Native Iris on the SPCNI website in the members only area. 

The Next Generation: Starting PCI Seeds

Kathleen Sayce, August 2018

With fall approaching, Iris seeds are ripening in the Northern Hemisphere, and seed exchanges are getting ready to distribute fresh seeds this coming winter. 

Seeds got away! Use organza bags to hold seeds until you can gather them.

Late summer is a good time to review both well-tested methods to start PCI seeds and known pitfalls that will definitely limit success. 

PCIs have tiny rhizomes and cannot be successfully shipped live around the world; shipping seed is the only way to share this iris group outside the US at this time. 

Pacifica Iris seeds naturally disperse from pods during mid to late summer. When fall rains begin in their natural growing area, those seeds start soaking up moisture, then germinate in winter to early spring. 

Nearly ready to harvest, one more week and the seeds in these Iris douglasiana x I. chrysophylla pods will be ripe and ready to harvest.

If you live on the West Coast of North America in zone 6 or warmer climates, you can put seeds in flats outside and let the weather work on the seeds directly.  Fresh seeds often germinate quickly. Older seeds may need two or three years to decide to grow. Seeds may stay viable for five to seven years. 

If you live elsewhere, where winters are colder, drier, or hotter, then a little creativity is needed. 

Cool wet winter conditions can be replicated by using a refrigerator or toilet tank to provide cold soaking. 

In the fridge, change the water daily. Use small plastic bags for each seed lot, and a small mesh strainer to catch the seeds. Turn them out into the strainer, rinse them under the tap in fresh cold water and also rinse out the bag. Use a spoon to tuck the seeds back into each bag. 

In a toilet tank, seeds go into mesh bags, and regular flushing of the tank provides clean cold water. 

Either way, let the seeds soak for 30 days, then take them out and plant in flats outside.

Pitfalls to avoid include: 

  Use warm water to soak seeds.

  Hold seeds in a location that is too dry. 

  Hold seeds where temperatures stay too warm. 

  Hold seeds where temperatures get too cold—generally colder than zone 6 or 7—but note that some species do well when held under a thick layer of snow over winter. 

  Use a soil mix that is heavy, drains poorly, and or is alkaline.

  Use containers that let roots heat up when sunny. 

Collectively, these iris seeds will decide that too dry, too warm (or hot), too cold, too wet, or too alkaline means ‘do not grow.’

Not shown:  the mesh cover for this flat, which kept the seeds well protected; ten seeds were planted, nine germinated, and eight are thriving.

As seeds germinate, they become tasty snacks for birds and rodents. Protect them! Hardware cloth covers over flats work wonders. 

When I started growing Pacifica Iris from seed, I thought I was getting old seed lots, or had the wrong soil mixtures. Nope, none of that:  I had persistent, sneaky, determined seed thieves, including voles, squirrels, jays and crows. 

All these tips, and more, can be found on SPCNI’s website at pacfiiccoastiris.org.

Finding the Goldilocks Zone for Pacifica Iris

June 19, 2018

Kathleen Sayce

Pacifica Iris are like Goldilocks when it comes to growing conditions:   Not too wet, not too dry, not too cold, and not too hot. Soils should be mildly acidic and well drained, with ample carbon and mulch. Avoid at all cost the combination of humid hot weather and warm alkaline water—plants will be toes up in days if they experience these conditions. Despite this, we have brave gardeners in summer-hot climates who continue to experiment with this fussy iris. 

Iris tenax in the garden; grown from seed in a protected styrofoam container

Water preferences:  Cool temperatures in summer, and slightly acidic at all times.  Not warm, never alkaline.  Established plants tolerate drought, but this statement hides the reality that in their native climates, Pacifica Iris have deep roots and cool root runs despite long dry summers. When in doubt, water more than less. 

Bare styrofoam--it does work, but it's fragile; this planter houses PCI seedlings for Garry Knipe's cross climate/cross continent experiment. 

Light:  Varies with temperature—the hotter the climate, the deeper the shade for this fussy group.  SPCNI members in Idaho, Arizona and Texas have grown Pacifica Iris for at least a few years by mulching, planting under roof overhangs, watering in summer, and arranging deeper and deeper shade as summer heat builds up. They also expect to grow new plants from seed whenever an extremely hot summer wipes out all their Pacifica Iris. 

Soils:  Moderately acidic, well drained, never soggy or saturated. Good carbon levels help promote soil fungi, which are probably key partners in keeping these irises happy. Carbon can be biochar, compost, or decomposing wood chips. 

Painted styrofoam:  The color is less obnoxious than white, but it is slowly wearing away, and the planter is only slightly less fragile.

Mulch:  Shredded bark or wood chips, or gravel. I use granite gravel, AKA chicken grit, to top all pots and planters, which helps keep seeds off the surface, soil from flying around in heavy rain, and slows down birds and rodents determined to eat iris seeds. 

Pots:  Like many gardeners, I began with dark colored plastic pots for growing plants from seeds. Lightweight, stackable, easy to store and reuse, it took me too many years to discover their drawbacks. Lightweight—they heat up quickly, soils dry out quickly, and roots heat too. 

Styrofoam containers followed, and the results were wonderful. Roots are cooler, plants are happier. But these materials are fragile, easily damaged by pecking, chewing, or as I learned when we had danger trees removed, by having large tree-like objects dropped on them. 

Styrofoam with epoxy cement coating, patched in two corners (upper right, lower left):  this planter survived a tree falling on it, and after patching, went to housing Iris hartwegii australis, which is happier under house eaves than in the garden. 

Treatments were tried to protect the soft surface, including:   

1. Paint, using various colors to make rock-like objects, as Ian Young and others in the Scottish Rock Garden Club have done). 

2. Epoxy concrete patch, mixed in small batches and troweled on thickly, mimicking rocks. This works well enough that the planter that did have a falling tree dropped on it was resurrected with additional patching material, and now houses a happy Iris hartwegii australis. 

3. Not yet tried—painting on cement, or troweling on hypertufa mix.

Hypertufa planter with PCI seedlings--the best solution so far.

4. Then came hypertufa planters, which are made with various combinations of perlite, cement, water, and peat / coir/ compost, or minus any organic material, and using a variety of containers as forms. Joseph Tychonievich, editor, The Rock Garden Quarterly, wrote an article about the wide variation in recipes for hypertufa in the Winter 2017/2018 issue. 

It’s my new favorite material for planters. Irises/lilies/crocus/tigridias/brodiaeas love it. Cool roots; never soggy, not even in 11 inches of rain in 8 hours; not too cold in winter, nor warm in summer. Tougher than styrofoam, and porous, so roots are well aerated. It’s also easy to make those important wire mesh covers to keep voles and jays off the seeds and tiny seedlings. 

Now, all I need is the time to make 50+ new planters!

Check roots to know when to transplant Pacifica Iris

February 26, 2017 

Kathleen Sayce

The West Coast is having a winter of pronounced weather, if one thinks of a series of Atmospheric Rivers (AR) as ‘pronounced’. I know I do—no soft drizzling days here, no ma'am. ARs are firehoses in the sky, huge rivers of moisture that deliver strong winds and warm rains from the Equator to higher latitudes. 

Above latitude 46 on the ocean, where I garden, rainfall is well above average for the water year, which began October 1st. Other areas are also above, including much of California, which is experiencing a definite wet season in an otherwise years-long drought. Those warm storms alternate with days of clear skies, balmy temperatures, and weeks of more typical winter weather, including snow, hail and much colder rain. 

Pacifica Iris clump with a little hail topdressing:  yes, this plant has active root growth below ground. 

This seesawing back and forth leads me to wonder what is going on below ground and when will be a good time to transplant irises, including Pacifica Iris. There is only one time to transplant them, and that is when plants are in active root growth. 

Healthy PCI buds suggest it's time to divide and replant--but check the roots first to ensure success. 

This means you have to gently scrape out the soil under the new buds and check the roots. Normally this is in the fall after rains begin, following dry summers, or winter into spring, before the annual summer drought begins. 

PCI 'Mission Santa Cruz' has a lovely new root, and is ready to be moved. 

Another general rule is that while Pacifica Iris are flowering and ripening seeds, they can be transplanted. I’d like to know how widely this works, so if you have experience with transplanting during spring, please let me know, or add a comment here at the bottom. 

If you live in other climate areas and grow Pacifica Iris, begin by checking roots on the plants you want to divide, repot or transplant.

Between hail storms today I went out and dug around a few plants to see what they are doing in the soil. I found a mixed bag, ranging from completely dormant (Iris tenax) to starting to grow (several recent Ghio hybrids). 

This PCI fan shows the roots from young (and active) on the left through the full sequence of older darker roots to fine roots off the rhizome on the right. It's ready to be replanted. 

I’ve mentioned before that hybrids from the Bay Area in California flower too early in my garden to escape heavy rain, and thus rarely set seed. If the rain is so hard that flowers are battered, bees aren’t flying around either.  These irises also begin growing very early—perhaps they are more attuned to day length than temperature. 

The finding in late February in my garden was that some new roots are starting to elongate just behind the new fans in some plants. There aren’t very many yet, one root per fan so far, where there will be four or more in a few weeks, but that’s enough of a sign of new growth that those early flowering hybrids can be dug up, divided, and replanted. 

Iris tenax is just starting to break winter dormancy; you can see the green shoots to the upper right. Roots are still brown. 

I will wait a few weeks for the others. Iris tenax, I. thompsonii, I. innominata and their various hybrids are still largely dormant, with few signs of new leaves on the first, and only a few new shoots on the latter.

Iris lazica has a bud. Not a PCI, but a good companion to them, and one that adds months of flowers to the garden, as does I. unguicularis. 

For comparison, in southern California, PCI are in active growth and starting to flower. Meanwhile, Iris lazica has put up a first bud, along with PCI ‘Premontion of Spring’, which has been flowering off and on since last September, as has Iris unguicularis. 

The next time you look at your Pacific Iris plants and wonder about getting starting dividing, go check the roots first. It’s the best way to ensure success.