If there is one plant you should avoid at the nursery, it is Ligustrum (also known as Privet). If you already have it growing in your yard, you may want to consider taking it out.
Why? Because Ligustrum is a highly invasive non-native plant that is taking over wooded areas throughout the Eastern United States, crowding out native species and drastically reducing biodiversity in those areas.
Ligustrum is one of the most problematic invasive species we are dealing with today in the U.S. (just ask my Master Naturalist friends who have spent endless volunteer hours trying to remove it!).
However, it is still being readily sold at nurseries throughout the country with other invasive species like nandina. Let’s work together to stop this!
What is Ligustrum?
Ligustrum (Privet) is an evergreen shrub / tree that can reach up to 50 feet high. It forms dense thickets, making it a popular landscaping shrub for hedges.
White blooms cover ligustrum between April and June, followed by dark purple to black fruit (called drupes) from late fall through the winter. This is when the plants are most easily identifiable.
The fruit is also what makes this plant so problematic. Birds easily disperse the fruit seeds to areas outside of where it was planted.
5 Reasons to Avoid Ligustrum / Privet
If there is a swear word among the Master Naturalist community, it is “ligustrum”! Admittedly, I had never heard of the plant before becoming a Texas Master Naturalist in 2020.
It didn’t take long before I heard about its negative impact on natural areas only to discover I had some growing in my own yard. Here are reasons why it is so bad:
1. Ligustrum easily escapes cultivation when birds disperse its seeds
Ligustrum trees are easy to identify in the winter because they are teeming with clusters of black fruit.
While birds like Cedar Waxwings do eat the fruit, it is not worth the problems created by them dispersing the seeds.
2. The trees quickly take over forested areas, forming monocultures
Privet is an understory shrub (although some can get up to 50 ft. tall). Once established in a wooded area, it crowds out most of the native plants in the understory and quickly changes the ecology of the area.
3. When privet takes over, pollinators disappear
You won’t see many pollinators in ligustrum filled forests. A study by the US Forest Service showed the wildlife impact of removing ligustrum.
Two years after removing ligustrum from a forested area, they recorded 4-5 times more bee species, and 3 times as many butterfly species as areas still filled with ligustrum.
The good news: removing the ligustrum brings back the pollinators!
4. Once it spreads, it is hard to eradicate
Removing ligustrum that has spread through a large area requires diligence and ongoing monitoring for regrowth after the plants are removed.
Read on to see how the Headwaters Sanctuary, a local San Antonio nature preserve, is engaging in a multi-year effort to rid its 53 acres of ligustrum.
5. The less we buy it, the less nurseries will carry it
This is important. The more we become informed as consumers, the sooner nurseries will stop selling these plants. Please ask your local nursery to not carry ligustrum (send them this article!).
Case Study: Ligustrum Removal at the Headwaters Sanctuary
I have seen firsthand the amount of work it takes to remove ligustrum that has invaded forested areas. Here in San Antonio, the 53 acre Headwaters Sanctuary is the largest nature preserve in the middle of the city. However it is flooded with ligustrum.
I recently interviewed the Headwaters’ Executive Director, Pamela Ball, to learn more about their ligustrum removal efforts.
Ligustrum escaped from surrounding neighborhoods
No one has ever deliberately planted privet at the Headwaters Sanctuary, yet its 53 acre wooded area is full of it. “For decades, homeowners in the surrounding neighborhoods have purchased Ligustrum as a hardy, evergreen hedge. We are inundated as a result.”, says Ball.
According to Ball, “Some zones are packed so heavily with ligustrum you can’t see the sky or hear birds. An ecologist told me she’s only ever seen one bird’s nest come out of ligustrum. You don’t hear birdsong in these parts of the sanctuary.”
The Headwaters created a multi-year plan to tackle infestation
Starting in the fall of 2019, the Headwaters started to do something about it in a big way. Ball divided the Sanctuary into 18 zones to help tackle privet removal and keep track of progress within each zone. So far, two zones have been worked on.
Each week a team of up to 20 volunteers from the community and local universities meets to cut down ligustrum, treat the stumps with herbicide, and put the branches through a wood chipper.
Teams of volunteers have removed 18,000 plants to date
Despite setbacks due to the pandemic and other hurdles, volunteers have steadily worked on two of the zones, removing upwards of 18,000 plants (80% of them ligustrum in various sizes).
“Some of the ligustrum plants we removed have multi-limbed trunks that can be two to three stories tall“, says Ball.
There is still a long way to go. Ball hopes to continue moving through all 18 zones, with a targeted completion date in 2025.
There are already signs of restoration of natives and wildlife
Ball recently assessed one of the zones where the ligustrum has been removed: “We have a pocket of Wafer Ash, Heritage Oaks, Hackberry, Condalia, Cedar Elm, Anaqua, and Hackberry in one of the zones we’ve cleared.”
“We have seen more bird activity as well. However, there is not a lot of understory yet because of the shade the ligustrum produced”, says Ball.
You can help the Headwaters initiative!
If you live in San Antonio, the Headwaters Sanctuary can always use more volunteers to help on Wednesdays and Saturdays with ligustrum removal. Email Pamela Ball at [email protected] for more information.
How to Remove a Ligustrum Tree
If you have privet growing in your property, here are the steps you can take to remove it:
1. If the plant is small, dig it out
The best thing you can do is get to the ligustrum seedlings before they grow larger. Dig them out, removing all the roots.
2. If the plant is large, cut it down to the ground
Larger plants may require a chainsaw to cut down.
2. Apply herbicide to stump
The Headwaters uses a heavy duty herbicide called Pathfinder 2 to spray the trunk and root collar. They combine the herbicide with dye so they can see it when spraying it.
3. Monitor for regrowth
Even with the herbicide there will be regrowth. Monitor every few months and hand prune and apply more herbicide as needed.
Types of Privet to Avoid
There are several different types of privet sold at nurseries, which should be avoided. All of them look fairly similar to each other.
1. Ligustrum sinese (Chinese Privet)
According to the USDA, Chinese Privet is one of the worst invasive species in the South. It thrives in the warm climate of the Southeast, and has completely taken over many of the wooded areas in that region.
Chinese Privet was introduced in the US from Asia in the 1800s and escaped cultivation by the 1930s, continuing to spread over the past nearly 100 years. According to Wildlife.org, it is the primary cause of biodiversity loss along streams in the Southeast.
2. Ligustrum vulgare (European Privet)
Native to Europe and Northern Africa, this species of privet is taking over forests of the Northeastern United States. It is listed in the Global Invasive Species Database.
3. Ligustrum japonicum (Japanese Privet)
Looks similar to Chinese Privet, but with larger and thicker leaves. It is listed as a Federal and Texas Department of Agriculture noxious weed.
4. Ligustrum lucidum (Glossy Privet)
Glossy privet can grow up to 50 feet tall. It is considered invasive in states including California, Florida and North Carolina.
Are All Ligustrum Plants Bad?
The quick answer is, yes, most of them are! All of the varieties listed above are invasive in certain areas of the U.S. There is a sterile variety of ligustrum called Sunshine Ligustrum that do not produce fruit, and therefore can’t spread by seed. By why plant it when there are more beneficial native plants out there?
Native Alternatives to Privet
Evergreen shrubs that are native to the United States make great non-invasive alternatives to privet. Here in Texas great native alternatives to privet include:
- Yaupon Holly
- Cherry Laurel
- Mountain Laurel
- Evergreen Sumac
- Wax Myrtle
- Dwarf Barbados Cherry