Archives for the "invasive plants" Category

English Ivy: A “Dirty Dozen” Plant

Have you ever looked along a highway and observed all the trees covered in vegetation from trunk to branches? It was most likely English ivy (Hedera helix), the final of […]

Japanese Honeysuckle: A “Dirty Dozen” Plant

Our Dirty Dozen plant of the week is Japanese honeysuckle (Lonicera japonica). This ornamental vine is still widely available in the horticultural trade, even though it has invaded all of the […]

Elaeagnus: A “Dirty Dozen” Plant

For this week’s Dirty Dozen plant, we have a triple threat: autumn olive (Elaeagnus umbellata), Russian olive (Elaeagnus angustifolia) and thorny olive (Elaeagnus pungens). All three Elaeagnus species are invasive, […]

Cogon Grass: A “Dirty Dozen” Plant

Cogon grass (Imperata cylindrica) is considered one of the top ten worst invasive plant species in the world. Even with its less-than-stellar reputation, it is a popular ornamental plant. Though […]

Italian Arum: A “Dirty Dozen” Plant

Our “Dirty Dozen” plant of the week is Italian arum (Arum italicum). Even though Washington is the only U.S. state to officially recognize arum as invasive, our horticulture staff have […]

Nandina: A “Dirty Dozen” Plant

This week, we are highlighting invasive Nandina domestica, commonly known as nandina, heavenly bamboo and sacred bamboo. Despite the name, this member of the Dirty Dozen is neither a true […]

A Lesson Learned: The History of Horticulture & Invasive Plants

Invasive Plants: How did They Get Here? If you’ve been reading our “Dirty Dozen” blog series, you’ve probably noticed a recurring theme in several of the articles: many invasive plants […]

Tree-of-Heaven: A “Dirty Dozen” Plant

This week we are featuring tree-of-heaven (Ailanthus altissima) as our “Dirty Dozen” plant. While this tree may have been used in folk medicine or even as an insecticide, it is […]

Oriental Bittersweet: A “Dirty Dozen” Plant

This week’s Dirty Dozen plant is oriental bittersweet (Celastrus orbiculatus). Since it is still available in the horticultural trade, we hope that the following information will convince you not to […]

Porcelain Berry: A “Dirty Dozen” Plant

This week’s featured member of the “Dirty Dozen” is Ampelopsis glandulosa var. brevipedunculata, commonly known as porcelain berry or amur peppervine. Most horticulture staff agree that this is the most […]