Miscanthus growing conditions and its invasiveness status

I am looking for an ornamental grass that doesn’t get over 5 feet tall
and am wondering what are the growing conditions for Miscanthus sinensis
(Gracillimus)? How much sun does it need, will it spread and invade my
other plants, is it invasive in our area (Seattle)?

I found several cultivars of Miscanthus listed on the local web site Great Plant
Picks. Miscanthus sinensis ‘Morning Light’ will reach about 5 feet tall
by 4 feet wide. This Colorado State University Extension article on from ornamental grasses may give
you additional ideas on grasses for your garden.
Although the following link is for southwest Washington gardens, this
Washington State University list of ornamental grasses may be of use.
It includes Miscanthus sinensis ‘Gracillimus,’ and indicates it does not
have a problem with self-seeding.

Excerpt:

Miscanthus

BE CAREFUL! Many are self-seeding.

M. sinensis ‘Gracillimus’ Maiden grass 4.5′ FS Most popular. Seldom
self-seeds.

M. sinensis var. purpurascens Purple maiden grass, Flame grass 3 – 5′ FS
Gorgeous red-orange fall foliage. One of the earliest flowering varieties
of maiden grass.

M. sinensis ‘Silberpfeil’ Eulalia 4 – 5′ FS One of the hardiest varieties
of maiden grass.

M. s. ‘Morning Light’ Dwarf maiden grass 4 – 5′ S, LSh Arguably best
all-around plant of the Miscanthus group. Blooms late with reddish
flowers.

M. s. ‘Adagio’ Japanese silver grass to 3.5′ S, LSh Compact with
silver-gray foliage. Two- to three-feet long panicles emerge pink, fade
to white.

M. s. ‘Flamingo’ Japanese silver grass to 6′ Large, loosely open,
pink-tinted inflorescences. Slightly pendant blooms appear late summer.

M. s. ‘Sarabande’ to 6′ Similar to Gracillimus, but finer textured.
Golden copper colored inflorescences in August.

M. s. ‘Strictus’ Porcupine grass 4 – 6′ FS One of the hardier Miscanthus
cultivars. Tolerates wet soils.

M. s. ‘Variegatus’ Variegated silver grass 4 – 6′ S, PSh Prefers
moist, fertile, well-drained soil.

M. s. ‘Zebrinus’ Zebra grass 4 – 8′ S, PSh

Update from 2012 on the invasive potential of Miscanthus cultivars:

Wendy DesCamp of the Washington State Noxious Weed Control Board reports the following:
“There is now a record of the plant growing in eastern Washington by the Columbia River in Benton County. [described as follows:] Shallow backwater on N shore of Columbia River . . . below McNary Dam, elev. 85 m, 45 degrees, 55.9 minutes N, 119 degrees 21.4 minutes west. Collected by Peter Zika, 17 June 2011.

From what I can find, this is the first collection of naturalized Miscanthus sinensis collected in Washington.”

The State Noxious Weed Board is considering whether it should be added to the monitor list or not. The monitor list is a list of plants the Board is keeping track of to collect information and to see if the plants are occurring or spreading in Washington.

UW Botanic Gardens Director, Professor Sarah Reichard had this to say about Miscanthus sinensis:
“We have had it in the Soest Garden for years and I have not seen it invade and I am looking for seedlings. However, not invading in the artificial environment of a garden, with water and nutrient inputs means little for invasion in the wild. I have not heard of it being invasive here, and I have been paying attention to both this species and Imperata cylindrica.It might be a good addition to the [noxious weed] monitor list.”

plant sources for natural reeds

I know that synthetic reeds are used in making some woodwind instruments like oboe and bassoon, but what plants are the source for the natural reeds? Is there a difference in sound quality between synthetic and natural reeds? Can the plants be grown in the Pacific Northwest?

There is an article entitled “Wind driven: A bassoonist nurtures reeds from rhizome to riff,” by Diana K. Colvin, published July 21, 2005 in The Oregonian. Oregon Symphony bassoonist Mark Eubanks grows Arundo donax in the Portland area. He says that the plants grow best in areas where the temperature does not drop below 10 degrees. They are also sensitive to drying winds and ground freezes. They perform well in areas where grapevines would thrive. His reed-making business, Arundo Reeds and Cane (now archived), has since been sold, but the company website offers a history of how Eubanks started it.

Another musician in New Jersey, Lawrence J. Stewart, has also made reeds from the plant. Musicians’ opinions on the sound quality of natural vs. synthetic reeds may differ but, in his experience, the sound seemed “very resilient and vibrant.” Unlike synthetic materials, the structure and therefore the sound of the reeds made from plants can vary widely. An article [“Anatomical characteristics affecting the musical performance of clarinet reeds made from Arundo donax L. (Gramineae)”] from Annals of Botany, vol. 81, Issue 1, found that “good musical performance was associated with reeds with a high proportion of vascular bundles with continuous fibre rings, and bundles with a high proportion of fibre and a low proportion of xylem and phloem. Significant differences in these anatomical characteristics were also found between reeds originating from cultivated plantation plants when compared to reeds produced from agricultural windbreak plants.”

This plant has been used for woodwind reeds for quite some time. According to “Arundo donax: Source of musical reeds and industrial cellulose” by Robert Perdue Jr. (Economic Botany, Vol. 12, No. 4, pp. 368-404), it may have been used in making flutes shortly after the late Stone Age.

The invasiveness of Arundo donax is essential to take into consideration. It is on Washington State Noxious Weed Control Board’s quarantine list. It is also considered invasive in many other parts of the country, including California. If you can salvage reeds that are being removed from a natural area and put them to musical use, so much the better. But I cannot recommend cultivating a stand of Arundo donax for any purpose.

invasiveness status of butterfly weed

Is butterfly weed invasive in the Northwest?

First, I have a plant name question for you: did you mean the shrub Buddleia davidii which is also called butterfly bush, or the herbaceous perennial Asclepias tuberosa, the plant most often referred to by the common names butterfly weed or butterfly milkweed?

In King County, Buddleia davidii is a Class B noxious weed, which means that its control is recommended but not required by law. Many gardeners grow this shrub as well as other less aggressive species. If you absolutely cannot live without this plant in your garden, you can go a long way toward preventing its spread by keeping the blooms deadheaded as soon as they fade (before they set seed).

Asclepias tuberosa can seed itself around, but it is classified as an endangered plant in New Hampshire, a threatened plant in Vermont, exploitably vulnerable in New York, of special concern in Rhode Island, and possibly extirpated in Maine. It attracts butterflies and hummingbirds. Here is more information so you can determine which plant you have in your garden:
Lady Bird Johnson Wildflower Center
USDA Plants Database

invasive plants and “sterile cultivars”

Is it safe to plant Cytisus scoparius ‘Moonlight’ here on Whidbey Island? I know that Scotch broom is thought to be invasive, but I wonder if maybe this variety is less of a problem.

Some sources (such as the State of Oregon’s noxious weed control board) have said that “sterile cultivars” of Cytisus scoparius are exempt from regulations governing noxious weeds. However, the Center for Urban Horticulture’s Professor Sarah Reichard, an expert on invasive species, says the following:

“The ‘sterile cultivar’ issue is huge worldwide. The reality is that sterile cultivars depend on the type of sterility: there are many reasons a plant might be sterile. Only a few of them can be considered to be stable under varying environmental conditions.

Regardless of what is done in Oregon, in Washington it is illegal to sell or grow any cultivars of Cytisus scoparius. Moonlight is less aggressive, but I have definitely seen it seeding out. But it does not matter how aggressive it is: it is still on the quarantine list in this state because that is the way the state law is worded. Island County may not have it on their high profile noxious weed list because it is only a B non-designate there because it is widespread. But our noxious weed (control) and our quarantine lists are two different things in this state and it is quarantined here.”

For future reference, here are links to Washington State Plant Quarantine and Noxious Weed lists.

invasiveness status of Alstroemeria in the PNW

I’ve just been given two pots of Alstroemeria psittacina ‘Variegata,’ a lovely red variety. Is this particular variety invasive here in the Pacific Northwest? I’ve grown the orange ones and then they took over–very hard to eradicate from beds. Does anyone know if the red ones are as invasive?

The Pacific Bulb Society lists this species under its previous name, Alstroemeria pulchella, and says it is weedy in some gardens and barely survives in others. Alstroemeria psittacina may be officially listed as invasive in some areas (in Australia, for example), but even if not officially designated as such, it may grow aggressively. This listing on the Floridata website, describes it as follows:

“This is a seductive plant. It is colorful, unusual, and exotic looking and effortless to grow once you get it going. Every gardener I know who has seen it has wanted it, begged a start, then nurtured it and delighted in it – for a few years. Then every one of them has come to curse the way it spreads and taken to ripping it out with a vengeance. Perhaps its best use is as breeding stock for developing more spectacular and less troublesome varieties of Alstroemeria.”

What you could do is grow your plants in a container, to avoid potential problems with weediness. I think aggressive spreading should be assumed with this genus unless otherwise specified.

lists for invasive and noxious weeds

Can you provide me with an extensive list of resources for checking whether a plant is invasive or a noxious weed?

Here is a list of helpful resources:

Washington State Noxious Weed List from the US Department of Agriculture

State noxious weed list and schedule of monetary penalties from the Washington State Legislature

Class A, Class B, and Class C

Washington Department of Ecology (aquatic plants)

Washington Invasive Species Coalition and their GardenWise handbook

King County Noxious Weed Lists

National Invasive Species Lists

Plant Conservation Alliance Alien Plant Invaders list

Invasives in British Columbia

The lists which are national in scope are useful too, as some plants not
yet officially listed as invasive here may still be plants to watch out
for.

There are a great many books on this subject. A recent one, co-authored
by a faculty member here, is Invasive Species in the Pacific Northwest edited by P.D. Boersma, S.H. Reichard, and A.N. Van Buren; Rebecca L. Gamboa, photo editor.
University of Washington Press, c2006.

on the parasitic plant dodder

I’m doing a science fair project on dodder plant and I’m seeking information about the plant, and a source of seeds or plants for the project.

Dodder is a parasitic plant that lives on crops, ornamentals, native plants, and weeds. Because it has limited chlorophyll, it can’t make enough food to support
itself, and so relies on the plants it colonizes for nourishment. It belongs to the genus Cuscuta, in the family Convolvulaceae (same family as morning glory). It was formerly referred to as Grammica.

Perhaps the reason that seeds and plants are not readily available is that dodder causes great damage to the plants it parasitizes. The U.S. Department of Agriculture’s plant protection and quarantine office states that “products, including foods, containing whole dodder seeds (Cuscuta spp.) are prohibited entry into the United States. APHIS regulates whole dodder seeds, both as a parasitic plant pest under Title 7 Code of Federal Regulations (CFR), Part 330 and as a Federal noxious weed under Title 7 CFR, Part 360.”

Here is additional information from University of California, Davis’s Integrated Pest Management website. Dodder is sometimes referred to as the “Vampire Plant,” as this University of Florida Extension page explains. Although your project, safe within the confines of a lab or classroom, might pose no threat, it is not legal to sell Cuscuta seeds or plants in the U.S.

ivy and other clinging vines

My question is about ivy for growing up a brick wall. What would you recommend? How do Boston ivy and English ivy compare for this purpose? We live in New Jersey.

First of all, it is important to know that clinging plants, such as
Boston ivy and English ivy have the potential to “damage old, soft mortar
and strip off pebbledash”. (Gardening with Climbers by Christopher
Grey-Wilson and Victoria Matthews) It is also suggested that these
vines have a “structurally sound surface and must be prevented from
reaching under house eaves and roof tiles and into window casements.”
(The New Royal Horticultural Society Dictionary Manual of Climbers and
Wall Plants edited by JK Burras and Mark Griffiths)

The New Jersey Invasive Species Strike Team has a factsheet on both English ivy (Hedera helix)and Boston ivy (Parthenocissus).

In addition to taking this information into consideration, it would also
be important to identify the amount of sunlight and the extent to which
the side of the house will be exposed to harsh winter winds and
temperatures. Neither Boston nor English ivy is recommended for full
sunlight. Boston ivy will give you more fall color and interest and will
withstand cold winters. (Simon & Schuster’s Guide to Climbing Plants by
Enrico Banfi and Francesca Consolino)

If you want to consider an alternative vining plant, you might want to install a trellis. That way you will not have to rely solely on vines which cling to the brick. You could try Clematis or some the honeysuckle species that are native to the northeastern U.S. There are several listed in this article (now archived) by William Cullina, “Alternatives to invasive or potentially invasive exotic species,” from the New England Wildflower Society:

Lonicera ciliosa (Orange Honeysuckle)
Lonicera dioica (Limber Honeysuckle)
Lonicera flava (Yellow Honeysuckle)
Lonicera sempervirens (Trumpet Honeysuckle)

Garden Wise : Non-Invasive Plants for Your Garden

[Garden Wise] cover

How do you convince gardeners, landscape designers, or nurseries to avoid planting or selling invasive plants? An effective tool is to provide alternatives – plants that provide a similar aesthetic but do not wreak havoc on our native plants and ecosystems.

“Garden Wise: Non-Invasive Plants for Your Garden, Western Washington Guide” is just such a tool. Published since 2006, the newest edition (2019) presents a selection of herbaceous, groundcover, aquatic, and even woody plants that are invasive in western Washington. Described typically with two photos, a close-up and a landscape shot of an aggressive stand, each entry will help even the casual plant observer identify the culprits. One example is Yellow Archangel ( Lamiastrum galeobdolon), a “trailing plant [that] easily establishes wild populations, in many cases as the result of improper disposal of garden cuttings or hanging baskets.”

Best of all, at least three alternatives are described for each invasive plant, also with photos that demonstrate their similar “look” and garden appeal. Many of these are natives. As an alternative to Yellow Archangel, the gardener is encouraged to consider Wild Ginger ( Asarum caudatum), a native groundcover that also grows well in part to full shade.

The Washington State Noxious Weed Control Board heads a long list of organizations (including the UW Botanic Gardens) that have produced this document. Coming soon is a similar booklet for eastern Washington. Both will be available in the Miller Library, or in .PDF format at the Board’s website (www.nwcb.wa.gov).

Excerpted from the May 2019 Leaflet for Scholars Volume 6, Issue 5.

Garden Tip #420

Growing native plants in the garden gives it a sense of place and a connection to local ecoregions. That simple sounding idea sometimes seems to ignite deep passions. True believers want to cast out all exotic (non-native) plants from the garden and even commercial sites with a goal of restoring the landscape to precolonial conditions. On the other side, skeptics argue trying to recreate an imagined pristine natural habitat ignores the reality that people and birds and the wind have always moved plants around the globe. Evolving to grow in a particular site means an organism is sufficiently suited to grow there, but not necessarily better suited than plants that evolved somewhere else.
The debate extends into whether or not anything can or should be done to contain invasive exotics. Do invasive plants decrease biodiversity? Does maligning exotic plants carry a subtext of nativism or xenophobia?

Keyword: Invasive plants