I live in Portland and recently bought my first home. I’m starting a native garden, but under a cedar tree there is a 40-square-foot patch of Italian arum. I have tried digging some out, but the roots are very deep. Parts of it are under river rock and landscape fabric.
I’ve read conflicting advice — some say dig it out, others say that can spread it. I’d prefer to avoid chemicals, but I’m wondering what options I have to control or eliminate it.
Italian arum can be very difficult to control once it is established. If you want to avoid herbicides, manual removal is the primary option, but it typically requires persistence over multiple years.
What to expect with manual removal
- Dig out plants as completely as possible, including tubers, roots and stems.
- Sift through the soil to remove any remaining plant parts, as even small pieces can regrow.
- Because the plant grows deeply and spreads easily, removal is often incomplete the first time, and follow-up is necessary.
Reduce spread
- Remove and dispose of berries before they ripen to prevent seed spread.
- Place all plant material in the trash, not in compost.
- Be aware that disturbing the soil can sometimes spread fragments, which is why repeated monitoring is important.
Herbicide considerations
Herbicides may not provide complete control of Italian arum, even when used correctly. Some products, such as those containing metsulfuron-methyl, are systemic and have residual activity in the soil. However, there are concerns about using these products near desirable plants, including trees like cedar, because they may cause unintended damage.
Ongoing monitoring
- Watch for new shoots in fall and winter, and for flowers in spring.
- Remove new growth early, when plants are easier to control.
- Expect to return to the area regularly to manage regrowth.
Italian arum spreads readily and can persist for years, so early and repeated action is key to keeping it from becoming a larger problem.
For more details, consult this entry on Italian arum on the Solve Pest Problems website.
¡Use los pesticidas con seguridad!
- Póngase ropa de protección y equipo de seguridad según las recomendaciones de la etiqueta. Báñese después de cada uso.
- Lea la etiqueta del pesticida—aunque lo haya usado antes. Siga al pie de la letra las indicaciones de la etiqueta (y cualquiera otra indicación que Ud. tenga).
- Tenga precaución al aplicar los pesticidas. Conozca su responsabilidad legal como aplicador de pesticidas. Usted puede ser responsable de heridas o daños resultantes del uso de un pesticida.