Richard T. Haard, Ph. D.
Plant Propagation Manager
Fourth Corner Nurseries

Interesting in their findings is that some areas have moved up 1 or even 2 temperature zones reflecting the real changes in our climate we all have been noticing. Keep in mind though that these zones are based on averages and we can still be vulnerable to arctic airmass surges that the mid-west and eastern states have experienced this winter. If you go to their website at arborday.org you will be able to search your own zip code and also download high resolution maps of the US, Alaska and Hawaii.

Elsewhere in this catalog, Veronica has written about perennial species, the shooting stars that ought to cross over into ornamental use because of their beauty and attractiveness to insects. I would like to make my own nomination of a shrub we have admired here and think has utility as an ornamental.

When I lived in the eastern US I always liked the Eastern Sweetshrub, Calycanthus floridus, mainly because of its spicy aromatic foliage. It is also a nice broadleaved shrub that is native in the eastern states from New York to Florida. This plant has indeed moved into the ornamental trade and like native Dogwood, Witchhazel, and Oregon grape are widely grown and sold as ornamentals.

Image of Western Spicebush in Natural habitat.

My nomination as underappreciated species is the Western Spicebush, Calycanthus occidentalis. This shrub is more limited in distribution, occurring in California and a limited area along the Columbia River valley of Washington. It is not considered as hardy as its eastern cousin and not widely used but we have successfully grown out a number of shrubs to maturity from seed collected in northern California. It makes a handsome plant in hardiness zones 7 and 8. But be aware that planting in a site exposed to northeast mountain winds could be deadly.

Western Spicebush has miniature magnolia like maroon flowers late spring thru early fall, fruiting mid-fall. In Northern California, this stout branched, handsome shrub occurs naturally along streams and on moist canyon slopes from 600 to 5000 feet, sharing approximately the same habitats as Red Osier Dogwood, Cornus sericea .  Where you have moist, rich soils this species can be interplanted for diversity with other natives such as Ninebark, Physocarpus capitatus , Peafruit Rose, Rosa pisocarpa , Black Twinberry, Lonicera involucrata  and Hooker Willow, Salix hookeriana.

Lastly, some discussion of plants we have either refused to grow or have in the past grown and wish we hadn't. Some of these plants are listed as noxious in the USDA database in certain states or are currently sold as ornamentals and have invasive growth habits when they escape into nature.

Image of non-native Phragmites australis taken along the shore of Great Salt Lake, Utah.

The plant I would like to highlight in this piece is Common Reed, Phragmites australis (syn= P. communis ). Recently, we had a customer call into our office wanting us to grow this plant because, as he explained, the native strain of the species is not listed as noxious by Washington State. True, it would be a useful candidate for a stormwater detention project, but we could find no assurance of the identity of propagules as a native strain and received a universal rejection for its usage in response to our inquiries to county level noxious weed board personnel.

From the findings of the Washington State Noxious Weed control Board:

"Rationale for Listing: The Non-native genotype of Phragmites australis will colonize, and displace the other plants in a wetland community, often forming, dense monospecific stands. Wildlife is displaced when wetland hydrology, structure and function are altered. Water quality deteriorates when water flow or circulation is adversely affected by this species. In Washington, Phragmites is rapidly invading the riparian zone of the Snake River displacing native wetland vegetation. In the Winchester waste way, it is noted to aggressively invade areas following the eradication of purple loosestrife. There are also noted problems on our wildlife refuges in eastern Washington."

Now for some of our less desireable plant selections we grew either by mistake or neglected to research their impacts. During our early days of native plant farming we were growing our willows from cuttings collected often from roadside habitats. I was still learning to identify these plants and picked up, instead of Pacific Willow, Salix lasiandra, a cultivar species with 'yellow stems' Salix alba vitiella or White Willow. This plant is indeed used around the country for conservation plantings, but in my opinion we should not be spreading such introduced species and cultivars, as it is easy enough to grow our native species from seed.

Another big mistake that happened was to collect cuttings of Basket Willow or Crack Willow, Salix fragilis, when I was attempting to find some propagation material for Geyer Willow, Salix geyeri. As soon as they leafed out, it became evident that we had the wrong plant. Salix fragilis is listed as invasive globally and its nasty habit of dropping branchlets plugs up streams and waterways.

Last in this category is Iris pseudoacoris or Yellow flag iris. This is a nice looking plant with ornamental properties, which is sold commercially, but is federally listed as an invasive aquatic plant. Commercial growers, as we did at one time, are spreading this plant and the much worse Purple Loosestrife, Lythrum salicaria. They should spend time comparing their growing list with state and federal noxious plant lists, now easily accessible at the USDA plants database.

Then, there is a plant we continue to grow that raises at least some eyebrows, Heracleum lanatum, Cow Parsnip. This is because an introduced, related cousin Heracleum mantagezzianum , Giant Hogweed, resembles Cow Parsnip and causes a toxic reaction upon skin contact for some people. Giant Hogweed can also be found on the federal noxious weed list. Our native cow parsnip is a wonderful plant with ornamental potential that is overlooked.

Other species we no longer grow are listed as invasive in some places but not others, these include: Ammophilla arenaria, European beach grass, (invasive and displaces our natives), Typha angustifolia , Narrow Leaf Cattail, and (also invasive and banned in some states), Lonicera tartarica , Tartarian Honeysuckle (banned in some states). Crataegus monogyna , Single Seed Hawthorne (banned in some states) deserves mention although we have never grown it, because we observe it more and more, invading and displacing native shrubs in the wild edges as it is moved around by feeding birds.

The best we can do in this plant propagation business is to be responsible in selecting the plants we grow and to do diligence on identification.