How to Kill Giant Hogweed: The Dangerous Plant Hiding In Your Backyard
It might sound like something out of a fairytale, but giant hogweed is no magical wildflower. This towering plant can cause serious skin burns and even long-term scarring if you're not careful. Found in backyards, ditches, and along property lines, it's spreading faster than many people realize. If you've spotted giant hogweed or think you might have, you need to act fast. Here’s how to safely identify, remove, and prevent this toxic invader from taking over your property.
Know What You’re Dealing With
Giant hogweed can grow up to 14 feet tall with thick, green stalks covered in purple blotches and white bristles. Its massive, umbrella-shaped flower heads can grow to over two feet wide. It’s often confused with Queen Anne’s lace or cow parsnip, but it’s far more dangerous than either of these plants. It’s also important to know that the sap is what causes problems. When it gets on your skin and is exposed to sunlight, it can lead to painful blisters, rashes, and even permanent scarring in some serious cases.
Wear Serious Protection
Getting rid of giant hogweed isn’t a job for gardening gloves and a sun hat. You’ll need to protect yourself with heavy-duty gear. That means goggles, thick rubber gloves, long pants, long sleeves, and boots. You should also tape your sleeves and pants closed to keep any sap from getting in. Cover every bit of skin still left exposed, and wash all the clothing that you wore separately after the job is done. Even a small brush with the plant while it's being removed can leave painful sap on your body or tools.
Cut Carefully and Strategically
If you’re going to remove giant hogweed by hand, timing matters. The best time to remove it is early spring when the plant is still young and small. Cutting above ground won’t do much long-term, but you can cut the root below ground, about 4 to 6 inches deep, using a sharp spade. Be sure to remove the root crown to stop the hogweed from growing back. And keep an eye on the area for the next few weeks. It often takes multiple tries before it stops coming back for good.
Don't Let It Go to Seed
Giant hogweed produces thousands of seeds per plant, and they can spread for miles when carried by wind or water. If you catch the plant after it’s already flowered but before seeds fully develop, you’ll want to bag the flower heads carefully and dispose of them according to your local hazardous plant guidelines. Never compost the flower heads or leave them in a brush pile because the seeds can survive for years in soil if not properly contained.
Use Herbicide Wisely
Sometimes physically removing the plant isn’t enough. A glyphosate-based herbicide can be effective, especially when applied to actively growing leaves before the giant hogweed plant flowers. But be careful. Herbicides can drift to and kill nearby plants and you may need to do multiple applications over a growing season.
Always read the label before you start spraying, follow local rules, and wear protection. Herbicides are best applied on a dry, calm day, so that wind and rain won’t make it spread to other plants. If you’re not comfortable handling chemicals, it’s always better to call a pro who knows how to deal with invasive weeds.
Don’t Burn or Mow It
You might be tempted to run giant hogweed over with the mower or toss the entire plant in a fire, but don’t. Mowing can spread the sap and seeds, and burning it can release toxic fumes. Both methods are risky and not effective for controlling the root system, which is the real problem. If you’ve already cut the plant and have dry stalks or flowers, seal them in a bag and dispose of them as directed by your local waste management services. You need to lean on the safer side with this one.
Watch the Area for Regrowth
Giant hogweed doesn’t go away easily. Its seeds can lie dormant in the soil for years, so even if you’ve removed it once, you’ll still need to monitor the area regularly to see if it comes back. Mark the location where the plant was and keep an eye out in spring for new shoots. If you see anything suspicious, act quickly before the giant hogweed matures. Keeping your yard trimmed, shaded, and well-maintained can also help keep the plant from returning and setting down roots again.
Report It If You See It
Because giant hogweed is considered a toxic weed in many places, reporting it helps stop it from spreading further. Contact your state’s department of agriculture or local environmental office if you spot it along trails, roadsides, or in public areas. Some states even have hotlines or online forms that you can fill out for invasive species reporting. Early detection and responding quickly is key. Your report might save someone else from a painful encounter or prevent the plant from spreading any further.
Take Care, But Take Action
Giant hogweed might be intimidating, but with the right knowledge and tools, you can safely deal with it yourself. Just remember that caution is key. If you’re unsure or nervous about removing it yourself, it’s a better idea to call in a professional to handle it. Either way, don’t ignore it. The longer giant hogweed is allowed to grow and spread, the harder it becomes to remove. A little work now saves a lot of trouble and pain later.