PlantRight is an organization that works to reduce the number of invasive plants sold at nurseries in California. Master Gardeners and other volunteers have helped conduct eight annual surveys to assess the number of invasive plants for sale and to encourage nurseries to stop selling them.

This year, PlantRight is not doing a nursery survey, concentrating efforts instead on outreach to landscape professionals such as architects, designers and contractors, and to water districts promoting sustainable landscaping. In the 2017 survey, the rate of nurseries selling invasive plants continued to decline, dropping to 29 percent in 2017 from 44 percent in 2014. For a list of invasives see:

I have battled many invasive, obnoxious plants and am happy to warn others about the hardships they can bring your way. I can say that I have not won a battle with invasive plants. When I bought my farm 42 years ago, I inherited some nasty plants along with the beautiful redbuds that caused me to name the place Redbud Farm.

Periwinkle (Vinca major) was growing in several places and still is today, although greatly reduced in abundance. I tried hard to eradicate it, but it has proven very resilient. The roots must be removed or it comes back, and I suspect residual seeds, too. It has become a major invasive plant in the shade of redwood trees on the North Coast, where it displaces native understory plants.

Another invasive is Algerian Ivy (Hedera algeriensis), which along with others of its ilk, provide good rat habitat. Although I removed it long ago, I keep finding new plants coming up and I am uncertain if this is due to birds dropping seeds or residual seeds from the original plant. It is mostly now a nuisance weed. Birds dropping seeds reminds me of Privet (Ligustrum sp.), whose seeds cause lots of weed trees requiring vigilant weeding, even if you don’t have one in your garden.

Italian Arum (Arum italica) is a woodland shade-loving plant that grows from corms. It resembles a jack-in-the-pulpit with large, arrow-shaped leaves. It grows in the winter and fades away with summer weather but leaves a large seed stalk with orange seeds. It reproduces with seeds along with deeply rooted corms that divide. It naturalizes readily and did so long before I bought the farm, so basically I was stuck with it.

In small locations you can cover the plant with a board and starve the corms for a year or more. This approach is not going to work when it is abundant everywhere. Herbicides do not work and digging out the corms is only practical in small areas. It is difficult to remove all the small corms.

I did remove Arum seed stalks before the seeds were scattered, which perhaps helped curb their spreading. Years ago, to develop my stepdaughter’s work habits, I paid her 2 cents for every seed stalk pulled, and she pulled a few hundred. Since all parts of the plant are poisonous, however, it is wise to be careful when being in contact with this plant. Would you believe that online nurseries will sell you, for only $25 for five corms, a bundle of misery and trouble?

Small-leaf spiderwort (Tradescantia fluminensis) is a shade-loving, creeping perennial herb that roots at nodes. I thought I had gotten rid of this plant, but it re-emerged to take over all shady understory areas. It smothers everything with vigorous growth and the rooted sections break off easily, making removal difficult. Herbicide such as a 3 percent glyphosate is recommended, but this may not be a solution in circumstances where other plants are present.

Spiderwort is a problem in Florida and New Zealand, where it covers vast areas of understory forests. Recently, I belatedly saw some being sold at a plant sale that I was involved with. I hope none were purchased and next year I will insist we not offer it for sale.

Bermuda buttercup or Buttercup oxalis (Oxalis pes-caprae) is impossible to eradicate as it grows from bulbs and makes a bunch of new bulblets every year. The flower is pretty and blooms in late winter and spring. I had to acquiesce to living with it.

Sometimes, the only way to get rid of invasive plants is to sell the farm; so I did. To all gardeners, I wish you happier gardening sans invasive plants, so plant carefully. For more information go to


If you have a gardening related question, you can contact the UC Master Gardeners at 209-953-6112. More information can be found at: