Invasives!

by John Nitta

When you’ve grown a lot of products over the years, things change. That is, some plants become very popular and desirable and some fade away. Some become what’s considered an “invasive plant.” I remember about twenty-five years ago, when the Chinese Tallow Tree (Sapium sebiferum), became very popular as a shade tree with fast growth and great fall color. As time went on the seed and resulting seedlings started spreading, popping up in natural riparian areas very rapidly.

Chinese Tallow Tree, once very popular, is a fast-growing, small shade tree with excellent fall color.

Over the years, The California Invasive Plant Council, or IPC, has a definition for “invasive non-native plants that threaten wildlands.” These plants in turn are then classified into ratings of “high,” “moderate,” and “Limited.” In studying the council’s listing of “invasive non-native plants that threaten wildlands,” I discovered several on the list that we should not be growing, and made a choice to discontinue six products. I determined these six because of their potential as being invasive to regions that we deliver our products to. Now, when I say that “I determined …” I mean to say that’s it’s strictly a choice of myself as a grower. That’s because I discovered there’s no law than bans me, or any other grower, from producing these plants.

It seems it’s also a matter of education. Several months ago, at our Placer Country Agricultural Commission meeting (where I serve as a member and the Nursery representative), our Agriculture Commissioner, Christine Turner, reported a call from a resident in the Auburn area, asking why the local Home Depot was selling Cytisus scoparius, Scotch Broom, considered to be a “high,” or “having severe ecological impacts” by the IPC. This was a knowledgeable layperson who called, and he or she knew darn right that the brooms are very bad plants! As to why the store was selling brooms in our area? Probably because it was shipped to many Home Deport locations, including areas that the plant was on the “bad” list. Apparently the grower, shipper, and/or store manager had no knowledge of the broom being a “bad” plant for the area.

We’ve been growing brooms for many years, for it is a popular plant in Nevada. It’s tough, hardy, spring-blooming, and almost a staple plant in the Reno area. At a plant conference this last winter, I met a Nevada State Ag person and asked about Cytisus scoparius. She said it is a good plant for their area, and it doesn’t spread around and become invasive, probably because of the tough climate they have. So, as a grower, we have to make choices. Although this plant has market value for us in Nevada, we are discontinuing it. We have to recognize the overall impact of its spreading as an invasive, and make the right choice.

High Ranch has grown several varieties of Scotch Broom, still widely used as a landscape ornamental in Nevada.

So, this is our plan, and it’s being implemented now. We are discontinuing growing and thus no longer offering the following six products:

• Cortaderia selloana - Pampas grass

• Cytisus scoparius - Scotch broom cultivars

• Pennisetum setaceum - Crimson fountaingrass

• Hedera (all) - (all English and Algerian ivy cultivars)

• Cotoneaster lacteal (C. parneyi) - Parney’s cotoneaster

• Sapium sebiferum – Chinese Tallow Tree

While these plants may be still listed in our current catalog, they won’t be available. I’m hoping other growers will make these tough choices as well.

Fountain Grass is still widely used as a ornamental grass. This planting is in Rocklin, California.