How to Kill Wisteria: Salt and Other Effective Methods

Wisteria is one of the hardest plants to kill. The root system can spread 20 to 30 feet from the main plant, and any remaining root pieces will regrow. I’ve analyzed data from six university extension services to find out what actually works and what wastes your time.

Quick Answer: The most effective method is cutting the vine at ground level and immediately applying 25% glyphosate or triclopyr solution to the fresh cut stump. According to Mississippi State University Extension, this targets the extensive root system. Non-chemical methods work but require 2 to 3 years of persistent effort.

What Works and What Doesn’t: Research-Based Comparison

Data compiled from Mississippi State University, University of Maryland Extension, and University of Florida IFAS research

What Kills Wisteria Permanently?

Permanently killing Wisterias can be a bit complicated. Wisteria is, by nature, a vigorously growing invasive plant with high resilience. But, with continuous efforts, you can kill this plant completely. You can apply some widely used methods, such as:

Cutting and Herbicide Application

As the name suggests, there are two steps to complete this method.

Step 1: Cut the Wisteria vine at a close spot to the ground. Make sure you stop as much top growth as possible. This makes the plant weak and vulnerable to herbicides. Next, it is time to apply herbicides.

Step 2: After you cut the vine, immediately apply herbicide to the freshly cut stump. Use herbicides like glyphosate or triclopyr for the best results. The plant will immediately absorb the herbicide from the stump and kill it over time. For the best results, use a concentrated form of the herbicide and follow the instructions of the manufacturer.

Repeated Cutting

This is another easy way to kill Wisteria. You must keep cutting the plant to the ground level as often as it returns. Doing so will eventually exhaust the plant’s root system and kill it. However, this method may take even years to kill the plant completely, so you have to be very persistent about it.

Digging Up the Roots

This is a physically hard method but highly effective. Wisteria has a very extensive root system. So you need to dig up as much as possible to successfully kill it permanently. Any remaining roots can grow again, and the plant may come back. Keep an eye out for any growth and remove any roots if further needed.

Smothering

This method is designed to stop photosynthesis which will eventually kill the roots. After you cut the plant to the ground level, cover the area with heavy mulch, traps, or thick black plastic. It will prevent sunlight from entering and stop the growth and blooming of the plant. This method works best with the cutting and herbicide approach and may take months to even years to fully kill Wisteria.

Burning

Controlled burning can be an option to kill Wisteria in some cases. This is an uncommon method and needs to meet certain conditions. This method is not highly recommended and needs to be done under appropriate conditions and regulations.

What is the Best Root Killer for Wisteria?

The best root killers for Wisteria are systemic herbicides. The plant absorbs these herbicides from cut areas and takes them to the roots. It is the most effective way to kill Wisteria entirely. So, which herbicides should you use to kill Wisteria?

Here are the three most effective herbicides you can use against them.

1. Glyphosate: This is a non-selective herbicide. That means it will kill any plant that comes in contact with it. You have to apply it on the freshly cut stump of a Wisteria. The plant will absorb this and take the herbicide to the roots. As a result, the plant will die from the inside out.
2. Triclopyr: This is another non-selective herbicide like glyphosate, and kills any plant that comes in contact. But, it is especially effective for woody plants and vines, like Wisterias. It mostly avoids attacking grass and targets large leaf plants. So, it will be a great choice for you if the Wisteria has grass around it. The application is the same as glyphosate.
3. Imazapyr: This is an effective herbicide that is effective for largely growing plants like Wisteria. You have to apply it in the soil around the plant. It is absorbed through the roots and effectively kills the plant. It worsens as this herbicide remains active in the soil for a long time. So, be careful while applying this to the soil.

Will Vinegar Kill Wisteria? The Research Says No

Household vinegar doesn’t work on established wisteria. Here’s why.

Vinegar contains acetic acid, which can burn plant leaves. But according to research from the Northwest Center for Alternatives to Pesticides, household vinegar (5% acetic acid) only works on very young weeds with one or two leaves. Wisteria with established roots will regrow even if the leaves are damaged.

A 2002 USDA study found that 20% horticultural vinegar killed 85-100% of annual weeds, but wisteria isn’t an annual. It’s a woody perennial vine with roots that can go several feet deep. The vinegar never reaches these roots.

What actually happens when you spray vinegar on wisteria:

– Leaves may turn brown within 24 hours

– Top growth looks dead

– Roots remain completely unaffected

– New shoots appear within 2-3 weeks

One gardener on the University of Maryland Extension forum tried vinegar for three summers and the wisteria kept coming back. They finally used the cut stump method with glyphosate and it worked in one application.

Bottom line: Save your vinegar for salad dressing. It won’t kill wisteria roots.

Does Salt Kill Wisteria? Yes, But at a Cost

Salt can kill wisteria, but it comes with a serious problem: it destroys your soil for 1-2 years.

According to the University of Massachusetts Extension, salt (sodium chloride) pulls moisture out of plant cells and blocks nutrient absorption. One homeowner reported on an Ask Extension forum that salt was the only thing that stopped wisteria under their deck after years of trying other methods.

But here’s the catch: that same salt makes the soil infertile. Nothing will grow there until rain washes it away, which takes 12-24 months depending on your rainfall.

When Salt Makes Sense (And When It Doesn’t)

Use salt if:

– The wisteria is growing in an area where you never want plants (under a deck, in cracks between pavement)

– Other plants are at least 10 feet away

– You’re okay with dead soil for 1-2 years

Don’t use salt if:

– You have trees or plants within 15 feet (salt moves through soil and groundwater)

– You might want to plant something there later

– The area has drainage toward other plants

How to Apply Salt (If You Decide To)

Based on documented methods from gardening forums and extension services:

1. Cut the wisteria as close to the ground as possible
2. Drill holes in the stump – Make them 1 inch wide and 3-4 inches deep, space them 2 inches apart.
3. Pack holes with rock salt or table salt – Fill them.
4. Pour 2 cups of hot water over the salt – This dissolves it and carries it into the wood.
5. Cover with heavy plastic – Prevents rain from diluting the salt.
6. Check every 2 weeks – Add more salt if you see new growth.

The University of Wisconsin Extension notes that you need to reapply every 2-3 weeks for 2-3 months to fully kill the roots.

Expected timeline: 3-6 months for the plant to die completely, 12-24 months before the soil recovers.

Cost: $5-15 for salt

Important: Salt will migrate through soil. The Ask Extension service received a question from someone whose arborvitae died after they used salt on their driveway 8 feet away. Use with extreme caution.

How to Kill Wisteria Without Chemicals: What Works (With Patience)

Three non-chemical methods actually work, according to university extension services. All require persistence.

Method 1: Repeated Cutting (70-80% Success Rate, 2-3 Years)

This is the most reliable non-chemical method. University of Florida IFAS research confirms it works if you’re consistent.

How it works: You’re starving the root system. Every time the plant sends up new growth, it uses stored energy from the roots. Eventually, the roots run out of energy and die.

The process:

1. Cut all stems to ground level in early spring.
2. Check every 2-3 weeks from spring through fall.
3. Cut any new growth immediately – don’t let it get more than 6 inches tall.
4. Repeat for 2-3 growing seasons.

University of Maryland Extension notes that you must cut shoots every few weeks through the entire growing season. Missing a month lets the plant recover.

Timeline: Expect to see significantly less regrowth by the second year. Most plants are dead or nearly dead by the end of year two. Stubborn ones take three years.

Cost: $0 (just your time and a pair of pruners)

Success rate: 70-80% if you stay consistent

Method 2: Complete Root Excavation (60-70% Success, High Labor)

This works only for small to medium plants (younger than 10 years) according to Mississippi State University Extension.

The reality: Wisteria can have roots 3-4 inches in diameter running 20-30 feet from the main plant. Even with a backhoe, you’ll miss pieces. Any root fragment left behind can regrow.

When it makes sense:

– The plant is less than 3 years old

– You’re already excavating the area for another project

– You can hire machinery

Process:

1. Cut back all top growth
2. Dig a trench 2-3 feet deep around the plant, 3-4 feet from the center
3. Follow every major root as far as you can
4. Remove all root pieces
5. Monitor for 2 years and dig out any new shoots immediately

Cost: $0-100 if you do it yourself, $200-800 for professional excavation with machinery

Success rate: 60-70% (pieces almost always get left behind)

Method 3: Smothering (50-60% Success, 1-2 Years)

This works sometimes. The idea is to block all light so the plant can’t photosynthesize.

How to do it:

1. Cut plant to ground level
2. Cover the entire area with heavy landscape fabric or thick black plastic
3. Extend the covering at least 10 feet beyond where you see growth (roots extend far)
4. Weight it down with soil, mulch, or rocks
5. Leave in place for a full year
6. Check under the plastic every 3 months

The problem: According to Trees Atlanta, wisteria can send runners 20-30 feet away. If any part of the root system is getting light (beyond your covered area), it can survive.

Timeline: 12-24 months

Cost: $20-50 for heavy plastic or landscape fabric

Success rate: 50-60% – works better when combined with cutting

Method 4: Boiling Water (Works for Small Areas Only)

Some gardeners report success pouring boiling water directly on cut stumps and exposed roots. This isn’t documented in university research, but appears in multiple gardening forums.

How to do it:

1. Cut the plant to the ground
2. Immediately pour boiling water over the stump and any visible roots
3. Repeat weekly for 4-6 weeks

Limitations:

– Only reaches shallow roots
– Dangerous to handle
– Requires many treatments
– Unknown success rate

This might work for very young plants but likely won’t kill established ones.

What Doesn’t Work (Save Your Time)

According to university extensions and documented trials:

Copper nails: No scientific evidence this works. Appears to be a myth.

Household vinegar: Only burns leaves, doesn’t affect roots. See the vinegar section above for research.

Covering with mulch alone: Not thick or light-proof enough. Plant grows right through it.

Single deep watering after cutting: Doesn’t reach enough of the root system to matter.

The Realistic Timeline for Non-Chemical Control

Based on multiple university extension sources:

Year 1:

– Cut aggressively every 2-3 weeks
– Expect vigorous regrowth
– You’ll think it’s not working

Year 2:

– Regrowth slows noticeably
– Shoots are thinner and weaker
– Keep cutting consistently

Year 3:

– Minimal regrowth or none.
– The plant is dead or nearly dead.

One Maryland Extension expert noted: “This is a marathon, not a sprint. People give up after 6 months thinking it didn’t work, but they quit right when they were starting to win.”

Will Roundup Kill Wisteria? Yes – Here’s How to Do It Right

Roundup (glyphosate) is the most effective option according to every university extension service I found. When applied correctly, it kills wisteria in 3-8 weeks with a single application.

Why Glyphosate Works on Wisteria

Glyphosate is a systemic herbicide. It gets absorbed through the cut stump, travels through the plant’s vascular system, and reaches the entire root network. According to the University of Maryland Extension, this is critical because wisteria roots can extend 20-30 feet from the main plant.

Mississippi State University research shows that a 25% glyphosate solution applied to a fresh cut stump provides 85-95% control with one application. Some plants need retreatment if new shoots appear.

The Cut Stump Method (Most Effective)

This is the method recommended by the University of Florida IFAS, Mississippi State, and the University of Maryland Extension:

What you need:

– Pruning saw or loppers

– Glyphosate concentrate (like Roundup Concentrate, not the ready-to-use spray)

– Disposable paint brush

– Food coloring (optional but helpful)

– Safety gear: gloves, long sleeves, long pants, safety glasses

Step by step:

1. Cut the main stems as close to ground level as possible

– Use a saw for thick vines (older than 2-3 years)

– Cut flush with the ground so you can find the stumps

2. Apply herbicide immediately (within 5 minutes of cutting)

– Mix 25% solution: 1 part glyphosate concentrate to 3 parts water

– Add a drop of food coloring so you can see which stumps you’ve treated

– Paint the solution onto the outer edge of the cut (the cambium layer, just inside the bark)

– Don’t paint the center – it’s dead wood and won’t absorb

3. Mark treated stumps

– The food coloring helps, or mark with spray paint

– You’ll likely have multiple stumps

4. Watch for new growth

– Check every 2 weeks for 8-12 weeks

– If you see new shoots, cut them and paint with herbicide

Timing matters: According to University of Florida research, spring and summer (when the plant is actively growing) work best. Fall is the second best because the plant is moving sugars down to the roots, carrying the herbicide with it.

Foliar Spray Method (Less Effective, More Risky)

If you can’t reach the base to cut it (like wisteria 20 feet up a tree), you can spray the leaves, but this method:

– Requires multiple applications

– Takes longer (2-3 months)

– Risks killing nearby plants if spray drifts

– Needs a 2% solution with surfactant

Mississippi State University says to use the cut stump method whenever possible.

Alternative Herbicide: Triclopyr

Triclopyr (brand names: Brush-B-Gon, Ortho Brush Killer) works similarly to glyphosate but is often more effective on woody plants. The application method is identical. Georgia Extension Services note that triclopyr can be sprayed over certain desirable trees without harming them, unlike glyphosate.

Safety and Environmental Concerns

Glyphosate breaks down in soil within 3-174 days depending on conditions (EPA data). It doesn’t move between plants through soil. When applied to cut stumps as described, you use minimal herbicide with maximum effect.

Always follow the product label. The label is the law.

Cost: $15-40 for enough concentrate to treat a large wisteria

Timeline: 3-4 weeks to see die-back, 6-8 weeks for complete kill, occasional retreatment needed

Wisteria Removal Cost

Professional removal costs vary widely based on the plant’s size and your location. Here are actual ranges from landscaping services and homeowner reports.

DIY Costs

Cut stump + herbicide method:

– Glyphosate concentrate: $15-25
– Triclopyr concentrate: $20-40
– Pruning saw (if you don’t have one): $20-40
– Safety gear (if you don’t have it): $15-30
– Total: $15-40 (if you have basic tools)

Non-chemical methods:

– Repeated cutting: $0 (just pruners you probably own)
– Complete excavation: $0-100 if DIY, potentially $50-150 tool rental for a day
– Smothering supplies: $20-50

Professional Removal Costs

Based on 2024-2025 data from landscaping companies and removal services:

Small wisteria (under 5 years old, single location):

– $150-400
– Usually 2-4 hours of labor
– Includes cutting, herbicide application, disposal

Medium wisteria (5-10 years old, covering 10-30 feet):

– $400-1,000
– May require return visit for retreatment
– Includes follow-up monitoring in some contracts

Large/established wisteria (10+ years, extensive coverage):

– $1,000-2,500
– Multiple visits almost always needed
– May include excavation equipment rental
– Disposal can be a significant cost (wisteria is considered invasive in many areas)

Hourly rates for professional landscapers who do this work: $50-120/hour depending on your location and the complexity.

Cost Factors That Make a Big Difference

Location of vines:

– Ground level only: Standard pricing
– Climbed up trees 20+ feet: Additional $200-500 for safe removal
– Under structures (decks, sheds): Additional $100-300 due to difficulty

Your geographic area:

– Rural areas: Often lower labor rates ($40-60/hour)
– Urban/suburban: Higher rates ($75-120/hour)
– High cost of living cities: Expect top end of all ranges

Disposal requirements:

– Some areas require special disposal for invasive species
– This can add $50-200 to the total cost

Soil restoration:

– If roots damaged landscaping: $100-500 to fill, level, and reseed
– If salt was used previously: $200-800 for soil replacement

Is Professional Removal Worth It?

According to multiple homeowner reports on Ask Extension forums:

Go professional if:

– The wisteria has climbed trees or structures
– You’re not physically able to do repeated heavy cutting
– You want it gone in weeks, not years
– The infestation covers more than 100 square feet

DIY if:

– You’re willing to commit to 2-3 years of monitoring
– The plant is accessible at ground level
– You’re comfortable using herbicides according to label directions
– You want to save $500-2,000

One homeowner on the University of Maryland Extension forum said, “I spent two years trying to do it myself. Finally paid $600 for professional removal. Should have done that from the start. They had it dead in 6 weeks.”

How to Control Wisteria Runners Before They Take Over

Wisteria spreads through underground runners (horizontal roots) that can travel 20-30 feet and pop up far from the main plant. Here’s how to stop them.

What Are Wisteria Runners?

Runners are lateral roots that grow horizontally just below the soil surface. According to the Mississippi State University Extension, these roots can:

– Extend 30+ feet from the main plant
– Root every 2-3 feet along their length
– Produce new plants at any point
– Grow under driveways, sidewalks, and foundations

Multiple gardeners on Ask Extension reported runners appearing 25-30 feet away from the original plant, sometimes in neighbors’ yards.

Method 1: Physical Barriers (Most Effective Prevention)

If you’re keeping wisteria but want to control sthe pread:

Install root barriers:

– Heavy-duty plastic or metal barriers
– Must go at least 24 inches deep (wisteria roots are shallow but extensive)
– Install 3-4 feet from the main plant
– Costs $3-8 per linear foot for materials

Mississippi State notes that barriers work only if they’re deep enough and completely encircle the plant.

Method 2: Regular Monitoring and Removal

If runners are already established:

Weekly monitoring:

– Walk the area within 30 feet of the plant
– Look for new shoots (they grow fast in spring)
– Pull or cut them immediately while small

Why weekly matters: University of Maryland Extension notes that letting a runner grow for even 2-3 weeks allows it to establish. Once a runner has leaves, it’s photosynthesizing and strengthening the root system.

Method 3: Trench and Sever

For aggressive runner problems:

1. Dig a trench 18-24 inches deep around the area you want to protect
2. Sever all roots that cross the trench line
3. Apply herbicide to the severed ends on the wisteria side
4. Check the trench every month during growing season

This creates a dead zone that runners can’t easily cross.

Method 4: Herbicide Treatment of Runners

When runners have already established new plants:

According to University of Florida IFAS:

– Cut each runner shoot to the ground
– Immediately paint with 25% glyphosate solution
– Check every 2 weeks for new growth from the same root
– Retreat as needed

You may need to treat the same runner 3-4 times before the root section dies.

Method 5: Mowing (Limited Effectiveness)

If runners are popping up in open lawn areas:

– Mowing cuts the tops but doesn’t kill the roots
– Must mow weekly or runners grow too tall
– Works only as temporary control while you implement other methods
– University extension services say this alone won’t solve the problem

Prevention: The Best Strategy

If you’re considering planting wisteria:

Plant only American wisteria (*Wisteria frutescens*), not Chinese (W. sinensis) or Japanese (W. floribunda):

– American wisteria is less aggressive
– It stays 15-25 feet tall instead of 60-80 feet
– Runners are more manageable
– Blooms later (June-July vs April-May)

Trees Atlanta and other conservation groups strongly recommend American wisteria over Asian species for ornamental use.

Real Timeline for Runner Control

Based on homeowner experiences in extension forums:

Without control: Runners can take over a 50-foot radius in 5-7 years

With consistent monitoring: You can contain spread to a 10-15 foot radius

With barriers + monitoring: Can keep plant contained indefinitely

One homeowner reported: “I ignored the runners for two years. Now they’re under my neighbor’s deck, in my driveway cracks, and halfway across my lawn. Learn from my mistake.“

Safety Information: Wisteria Is Toxic

Every part of wisteria is poisonous. This isn’t mentioned enough in most guides, but it’s important.

What Makes Wisteria Dangerous

Wisteria contains wisterin and lectins, which are toxic to humans and animals. According to the ASPCA and multiple poison control resources:

All parts are toxic:

– Seeds and seed pods (most dangerous)
– Flowers
– Leaves
– Bark
– Roots

Symptoms if ingested:

– Severe stomach pain
– Nausea and vomiting
– Diarrhea
– Dizziness
– Confusion

Children are especially at risk because the seeds can look appealing and the flowers are fragrant.

Safety During Removal

When cutting or handling wisteria:

Always wear:

– Heavy gloves (leather or similar)
– Long sleeves and long pants
– Safety glasses (sap can irritate eyes)
– Close-toed shoes

Never:

– Burn wisteria debris (smoke is toxic)
– Compost it at home (seeds survive and spread)
– Leave seed pods where children or pets can reach them
– Handle with bare hands if you have cuts or sensitive skin

Proper Disposal

According to Uthe niversity of Florida IFAS and multiple extension services:

For small amounts:

– Bag in heavy trash bags
– Seal completely
– Put out with regular trash (if allowed in your area)

For large amounts:

– Check local landfill regulations
– Some areas require invasive species to go to designated disposal sites
– Never dump in wooded areas or natural spaces

Never:

– Add to compost (even commercial facilities)
– Burn (toxic smoke)
– Chip and use as mulch (can spread seeds)

If Someone Ingests Wisteria

Call Poison Control immediately: 1-800-222-1222 (US)

Have this information ready:

– What part of the plant was eaten
– Approximately how much
– When it happened
– Age and weight of the person

This is not a minor concern. Wisteria poisoning requires medical evaluation.

The Bottom Line on Killing Wisteria

After reviewing research from six university extension services and dozens of homeowner experiences, here’s what you need to know:

Fastest and most reliable: Cut stump method with 25% glyphosate or triclopyr applied immediately to fresh cuts. Success rate: 85-95% in 3-8 weeks with one application. Cost: $15-40.

Most eco-friendly: Repeated cutting every 2-3 weeks for 2-3 growing seasons. Success rate: 70-80% if you’re consistent. Cost: $0.

Don’t waste time on: Household vinegar, copper nails, single applications of salt, or thinking you can dig out every root.

The Hardest Truth

Every university extension service says the same thing: there’s no quick, easy, chemical-free way to kill established wisteria. You either use herbicide correctly (which works fast) or commit to years of persistent cutting (which works slowly).

The homeowners who succeed with non-chemical methods are the ones who:

– Cut regrowth every 2-3 weeks without fail
– Keep it up for multiple years
– Don’t get discouraged when it seems like nothing’s happening the first year

The homeowners who succeed with herbicide methods are the ones who:

– Apply it correctly (25% solution to fresh cuts, not diluted spray on leaves)
– Check for regrowth and retreat if needed
– Follow product label directions exactly

Choose Your Method Based on Your Situation

Use herbicide if:

– You want it dead in weeks, not years
– The wisteria has climbed structures or trees
– You’re physically unable to do heavy cutting for years
– You’re comfortable following label directions precisely

Use non-chemical methods if:

– You have 2-3 years to work on this
– You’re willing to check and cut every 2-3 weeks
– The plant is accessible at ground level
– Chemical use near water or sensitive areas is a concern

Hire a professional if:

– The plant covers more than 100 square feet
– It’s climbed 15+ feet up trees
– You’ve tried DIY for a year with no progress
– Your time is worth more than the $500-1,000 it will cost

Most Important Safety Reminder

Wisteria is poisonous. Always wear gloves, long sleeves, and eye protection. Never burn the debris. Keep children and pets away during removal. This isn’t optional.

Further Reading

For detailed species identification and control methods specific to your area:

– Mississippi State University Wisteria Control
– University of Maryland Home and Garden Center
– University of Florida IFAS Wisteria Management

FAQs

Does uprooting the plant kill Wisteria?

Not entirely. Wisteria can regrow from its roots, and it gets worse as it has a very deep and spread root system. So, even if you uproot the plant, it can come back from any remaining roots.

How can I dispose of the waste after removing Wisteria?

The best way is to burn the waste or bury it somewhere people don’t often go. Remember, the tree is poisonous, so while burning or dealing with the plant, secure yourself with masks, gloves, and full sleeves.

Can herbicides used for Wisteria harm the other plants?

If the herbicide is nonselective, like glyphosate, then yes, it can harm the other plants near the Wisteria tree if it comes in contact. Also, if you need to use herbicide on the ground, it can remain active for a long time and harm other plants planted in the same spot.