How to Effectively Remove Invasive Honeysuckle (Full Guide)
At first glance, invasive honeysuckles may look similar to native honeysuckles. But they can be harmful to our environment and even be very bad for our health! It can be a nightmare, but there are ways to quickly identify them and effectively remove invasive honeysuckles.
Invasive honeysuckle can be removed by 1) pulling out young shoots, 2) cutting larger honeysuckles, and 3) applying glyphosate after cutting to prevent them from growing back. Use gloves, loppers, or shears when removing the honeysuckle.
Invasive honeysuckles became popular in the 1860s and were originally grown in the US as ornamental shrubs. However, these aggressive and non-native plants have spread far and wide and have been wreaking havoc since then. To prevent them from overtaking your garden, here are the best ways to get rid of invasive honeysuckles!
1. Pull Out Young Shoots
Small honeysuckles emerging in the spring should be removed immediately to prevent them from growing bigger. These invasive honeysuckles can be pulled or dug out of the ground easily using gloves and a shovel.
The perfect time to pull out honeysuckle sprouts is in the spring, when the new shoots are still small and frail. During this time, they can be pulled out with little effort.
If the honeysuckle in your garden is still small, you can pull them out of the ground with gloved hands. If you have difficulty, a shovel will help you dig them and their roots.
For wider infestations, I suggest asking someone to help. It might be tempting to mow them down, but if the plants still have healthy roots, they’ll only grow back!
This is one of the reasons why they’re so hard to remove. But by pulling invasive honeysuckles out directly, you’ll be able to help combat this.
2. Cut Large Honeysuckles
Taller honeysuckles have thicker stems that can be cut with loppers or chainsaws. If the invasive honeysuckle has bloomed, cut and dispose of the fruits and flowers first to prevent them from spreading seed. Make even cuts before applying herbicide.
These plants can easily grow back even with just a few roots, so you have two options. You can cut the invasive honeysuckle and dig out their roots, or use herbicide after cutting them to get rid of them.
Either way, you must first cut the unwanted honeysuckle down at the base using a pair of sturdy shears or loppers. For those who must tend to multiple honeysuckles at once, a chainsaw might be easier to use, but be careful!
If you’d like to use herbicide though, I suggest making even cuts. You’ll learn why this is important in a bit.
Once again, it’s best to do this in the spring before the honeysuckles bloom.
But if it’s in the middle of summer, and the plants have already produced flowers and fruit, carefully remove and dispose of them in a garbage bag. This will prevent the berries from spreading and creating new plants.
After the honeysuckles are cut, you can use a shovel to dig up their roots. But if you’d rather skip this step, the herbicide is a useful alternative.
3. Apply Glyphosate After Cutting
After cutting the invasive honeysuckles, cover the stumps with glyphosate using a sponge. The plant will absorb the herbicide and the roots will die in the spring. Do this in late summer and fall for optimum success.
If the infestation is serious and there’s no way to remove the root systems without taking 3 days off, you can apply herbicides after cutting them down.
First, you’ll need glyphosate. This is a systemic herbicide, meaning it is absorbed by the plants and taken into the system. RoundUp is a good option that is widely available.
This herbicide on Amazon contains glyphosate and can be used on invasive honeysuckles.
You can use glyphosate solutions as low as 20% in concentration. Apply the herbicide on the freshly-cut stump with a sponge for full coverage. By making an even cut, as I suggested earlier, it will be easier to apply the glyphosate.
Pro Tip: If your herbicide is colorless, mix it with bright food dye to see it more clearly.
The best time to do this would be in late summer and early fall, when the herbicide will be carried directly to the root systems and kill the plant, preventing it from growing back.
Avoid spraying any herbicide in the soil, as this could prevent other plants from growing. With some caution, however, this method is ideal if you don’t want to rip and remove all the roots underground by hand.
4 Reasons Why You Should Remove Invasive Honeysuckle
Invasive honeysuckle should be removed because 1) the berries can be toxic, 2) they compete with native plants, 3) increase tick populations, and 4) increase mosquito populations as well.
When it comes to invasive plants, many of us are told to report them or remove them on sight. In Hawaii, skilled marksmen in helicopters are hired to shoot down hard-to-reach invasive plants with herbicide-filled paintballs.
You might be wondering, why is there so much effort being put into removing seemingly harmless plants?
Invasive honeysuckles are not inherently malicious. But grown in North America, they can cause problems for many lifeforms, including humans. Let’s review some of these concerns to help you learn why invasive honeysuckles should be removed.
1. The Berries Can Be Toxic
Invasive honeysuckle berries can cause vomiting and diarrhea in humans and animals when eaten in large amounts. Additionally, the berries are low in nutrition for birds and will encourage them to nest in areas with more predators.
Although the berries are edible and are used in Asia, eating these berries in large quantities can be toxic and cause vomiting, diarrhea, and even respiratory failure.
Honeysuckle berries are toxic for humans and harmful to cats and dogs in large amounts.
But what about the birds? Some people argue that honeysuckles are beneficial and provide food for native birds, so why should you remove these plants?
The truth is, invasive honeysuckle berries have little nutrition and are the equivalent of junk food for birds. The berries can even encourage birds to nest in non-native areas and expose them to more predators than usual.
It can feel satisfying to watch birds flock to your garden to eat honeysuckle berries, but the truth is, these plants do more harm than good.
2. Competes With Native Plants
If allowed to grow, invasive honeysuckles will compete with and kill native plants by competing for water and sunlight. Additionally, they are suspected to be allelopathic, releasing toxins in the soil to kill other plants.
Left unchecked, invasive honeysuckle can kill your other plants by competing with them and releasing toxins in the soil.
Research has revealed that invasive honeysuckles from Japan have the potential to be allelopathic. Allelopathy is when plants release chemicals in the soil to kill their neighbors and take all the nutrients and water in the area for themselves.
Aside from this chemical attack, invasive honeysuckles tend to grow up to 10 feet (3.05 m) tall. In other words, they can also block sunlight from reaching other plants, effectively smothering them.
Because of this, Japanese honeysuckle has been banned in Indiana and New Hampshire.
Now that I’ve discussed the two most common ways invasive honeysuckles can negatively impact the environment, it’s time to talk about the lesser-known but equally dangerous harms of not removing these plants.
3. Increases Tick Population
Invasive honeysuckles can attract wild deer for ticks to feed on and thrive. This can increase the tick population and the chances of contracting tick-borne diseases.
Honeysuckles can quickly form entire thickets. Not only does this aggressive growth harm birds and other plants, but this also affects humans.
Research done in 2010 showed that honeysuckle-invaded areas had higher populations of ticks. This was because the honeysuckle had attracted large numbers of deer.
These wild deer, in turn, were excellent hosts for ticks. With such large numbers of ticks in the area, this led to a higher risk of people catching tick-borne diseases.
For a tick-free garden, grow these 19 Plants That Repel Ticks.
4. Increases Mosquito Population
Invasive honeysuckle plants can significantly increase the mosquito population in the area by providing them with suitable breeding grounds.
Some mosquitoes, such as Culex restuans, preferr to lay eggs in the leaf litter of honeysuckle plants. This mosquito is a common carrier of the West Nile virus, a mosquito-borne virus that can cause fevers, seizures, and paralysis.
Remember, the under canopies of honeysuckles tend to have less sun and warmth. Aside from preventing plants from growing, this condition allows mosquitoes to flourish.
By clearing invasive honeysuckle off your property, you’d effectively remove potential homes for mosquitoes to breed in and attack you and your loved ones.
It might not be obvious, but these plants have much more impact on our environment than we realize!
Identifying Invasive Honeysuckles (5 Key Features)
Invasive honeysuckles have 1) opposite leaves, 2) fragrant flowers, 3) red and black berries, 4) hollow stems, and 5) grow in areas with full sun.
First off, how do you even tell if you have invasive honeysuckle in your yard? Is it native or non-native? They can look quite similar, but after further inspection, you should be able to identify invasive honeysuckle!
1. Opposite Leaves
Invasive honeysuckles have oval-shaped leaves that grow opposite each other.
Leaves growing opposite of each other is one of the very distinctive features of invasive honeysuckles.
The leaves are oval-shaped and smooth on the edges, with a slightly glossy look. The plant might look like a sprawling vine, but it is actually a shrub.
In particular, the leaves of Amur Honeysuckle will have hairs growing on them and have a long, prominent point at the end.
2. Fragrant Flowers
The flowers of invasive honeysuckles are very fragrant and can be found in spring. These blooms have four petals each and can be white, yellow, or pink.
Despite their aggressive nature, invasive honeysuckles have very fragrant flowers with scents that most people find pleasing.
Many people describe the scent as sugary or fruity, or just generally sweet.
The aromatic blooms are white at first before turning yellow or pink. Four petals can be counted on each of the flowers. Usually, they open in spring.
3. Red and Black Berries
Red and black berries can be found on invasive honeysuckles in the summer.
After the flowers bloom, they will be replaced with berries.
The immature berries are initially red before ripening to a dark blue-black hue. These berries tend to grow in clusters like flowers.
Invasive honeysuckle berries are highly attractive to birds and can be seen throughout the summer.
4. Hollow Stems
Invasive honeysuckles have hollow stems and dull, gray bark that look like they are peeling.
This is one of the key characteristics of invasive honeysuckle.
You can tell the difference between an invasive honeysuckle and a native one easily by checking out their stems.
Just snap the stem in half to check the middle. Invasive honeysuckles have hollow stems, while native plants generally do not.
The bark of the stem is also grayish brown and will look as if it is damaged or peeling. The plant will have multiple stems and arching branches.
5. Grows in Full-Sun Areas
The invasive honeysuckle is a sun-loving plant that grows near open borders, edges, or roadsides, where it can receive as much sunlight as possible.
While other plants are driven away by urban areas with human activity, many invasive honeysuckles are attracted to these areas due to their wide open spaces.
This makes it easier for the plant to soak up as much sun as possible. Because of this, it often sprouts along roadsides, borders, and edges.
Non-native honeysuckle can also grow in areas with light shade. But since it needs strong sun, this does not happen frequently.
Native Honeysuckle Alternative
The coral honeysuckle is native to North America and is a non-invasive alternative for X. Its trumpet-shaped flowers are attractive to pollinators and can safely be grown in the garden without concern of it competing with other plants.
Do you enjoy the look of honeysuckles, but don’t want to hurt the ecosystem in the process? Consider planting native honeysuckles instead!
Take the coral honeysuckle, for example. It prefers to grow in full sun and grows bright trumpet-shaped flowers, which is why this honeysuckle is sometimes called the trumpet honeysuckle.
It’s attractive to birds and pollinators and makes a beautiful vining plant. Don’t worry though, it can still be controlled with ease, unlike invasive honeysuckle.
Plant nurseries will sometimes sell invasive honeysuckle under a different name, so just be sure to confirm the honeysuckle you’re buying is specifically Lonicera sempervirens.
Its flowers aren’t as fragrant as its weedy cousins, but this is a small price to pay to grow a native plant that is not harmful to the ecosystem.
FAQs
Where is honeysuckle invasive?
Honeysuckle is invasive in many states such as Indiana, New Hampshire, New York, Texas, and Illinois. The Japanese and Morrow honeysuckle are invasive in Ontario, Canada, and cannot be legally grown.
Which honeysuckle is invasive?
There are over 180 honeysuckle species, but the Morrow, Amur, Tatarian, and Japanese honeysuckles are the ones known to be invasive. These plants tend to grow aggressively and should not be grown at home.
Summary of Removing and Identifying Invasive Honeysuckles
Gardeners must immediately remove invasive honeysuckle by pulling out the young shoots, cutting large honeysuckles down, and covering freshly cut stumps with glyphosate to prevent them from growing back. Invasive honeysuckles have opposite leaves, fragrant flowers, red and black berries, hollow stems, and grow in full sun.
Although invasive honeysuckles look pretty, their berries can be toxic and encourage native birds to nest in dangerous places with more predators, and the plants will compete with native growth and kill them. Large infestations can even increase tick and mosquito populations, so they must be cleared immediately.
Sources
- “Honeysuckle Invasive Species Profile” by n/a in Iowa State University
- “Lonicera japonica” by n/a in NC State University
- “Bush Honeysuckle Control” by n/a in Missouri Department of Conservation
- “Invasive Species Highlight: Bush Honeysuckles… Not for the Birds!” by n/a in The Pennsylvania State University
- “Evidence for allelopathic interference of Japanese honeysuckle (Lonicera japonica) to loblolly and shortleaf pine regeneration” by B. W. Skulman, J. D. Mattice, M. D. Cain and E. E. Gbur in Cambridge University
- “Invasive honeysuckle eradication reduces tick-borne disease risk by altering host dynamics” by Brian F. Allan, Humberto P. Dutra, Lisa S. Goessling, Kirk Barnett, Jonathan M. Chasea, Robert J. Marquis,Genevieve Pang, Gregory A. Storch, Robert E. Thach, and John L. Orrock in Washington University
- “Impact of an Alien Invasive Shrub on Ecology of Native and Alien Invasive Mosquito Species (Diptera: Culicidae)” by Ephantus J. Muturi, Allison M. Gardner, and Jeffrey J. Bara in Oxford University
- “Rediscovering an old favorite – The Coral Honeysuckle” by Ralph E. Mitchell in University of Florida