This Fast-Growing Herb Easily Runs Wild In Gardens. Here's How To Stop It

An herb loved for its uniquely spicy roots, horseradish (Armoracia rusticana) can quickly become a major problem in your yard if left unchecked. Horseradish is a perennial plant that spreads aggressively, taking over large spaces and crowding out other plants. It has a deep, tuberous root system that makes it difficult to remove by hand. Native to Europe and Asia, Horseradish can easily become invasive in parts of the United States, especially in regions with moist soil and mild winters, where it thrives.

If you choose to plant horseradish, container planting is a good way to keep it from spreading in your garden. You can, and should, use containers even if you want to plant them in the ground. Raised outdoor containers and even those buried underground can help control the spread. Mulching can also help suppress horseradish growth. However, if you already have an overgrowth of horseradish, there are steps you can take to eradicate this tough plant.

A combination of mechanical and chemical treatments is the most effective method of dealing with these unwanted plants. Mechanical removal alone is a very effective method for eradicating horseradish. This method also requires the most physical labor, especially if horseradish has spread throughout your yard.

Using a spade or similar tool, dig up each plant from the rhizome. Then, remove any roots that remain in the soil. Even the smallest horseradish roots can regenerate, so make sure to pull every root you can. Dealing with a horseradish problem requires patience. Because it's difficult to remove every scrap of root, you will likely need to repeat this process until new plants stop sprouting.

Herbicides can also be effective on adult horseradish, though they are more effective on the young shoots that crop up after mechanical removal. If you plan to go the chemical route, choose a systemic weed killer, such as Round-up, that permeates plants down to the roots. If the problem persists after combining these methods, you can try covering the plant with a tarp to block light and kill the plant. In some cases, planting other ground covers such as grass seed may choke out new horseradish growth and stop it from spreading further.