Tansy, with its fern-like foliage, alluring fragrance, and button-shaped golden flowers, can easily win your heart. But before you rush into a relationship with this plant, it’s important to take a step back and consider both its benefits and risks. As someone who’s learned the hard way with invasive plants like mint, aquilegia, and periwinkle, I’m cautiously approaching tansy with a watchful eye.
Reasons Not to Grow Tansy in Your Garden
Tansy may seem perfect at first, but it has its darker side. It contains a toxic essential oil that can cause serious health issues, including liver and brain damage, and can even be fatal to humans and animals. Its toxicity doesn’t stop there—handling the plant’s leaves may trigger allergic reactions in some individuals.
Another major concern is its invasive nature. Tansy spreads rapidly through both reseeding and underground rhizomes, making it difficult to control. In certain regions of North America, it’s classified as a noxious weed, prohibited from cultivation due to its aggressive growth.
Reasons to Consider Growing Tansy
Despite its flaws, tansy does have redeeming qualities that make it a worthwhile consideration for your garden. For one, it’s hardy and adaptable to a variety of soil types, requiring little maintenance. It thrives in partial shade, making it perfect for filling neglected garden spaces, and is drought-tolerant once established. Additionally, tansy helps improve soil quality by accumulating potassium.
Tansy also acts as a natural pest repellent. Its toxic essential oils are effective in deterring ants, flies, mosquitoes, ticks, and even mice. While these claims may sound exaggerated, the oils can be used to create insecticides, supporting their reputation. The strong scent of tansy’s flowers and leaves can also be harnessed to make natural insect repellent for the home, such as dried bouquets or potpourri.
For gardeners, tansy attracts beneficial insects as well. Honeybees are drawn to its flowers, while ladybugs often lay eggs on the plant. It also hosts other pest predators, including braconid wasps and minute pirate bugs, which can help control garden pests.
Though larger quantities of tansy can be toxic, small amounts of its leaves and flowers are edible. They can be incorporated into omelets, stews, and salads, though I personally prefer to admire tansy from a safe distance—some mystery is necessary in any relationship.
A Cautious Approach
Given its potential for invasiveness and toxicity, I recommend growing tansy with caution. My own tansy plant resides in a container, where it’s easy to admire without worrying about it taking over the garden. If you’re looking to add variety, consider pairing tansy with other plants like feverfew, lupins, foxgloves, and asters. With careful management, tansy can be a beautiful, useful addition to your garden—but it’s best to take things slow.
Ultimately, tansy’s charm might make it a keeper, but only if you manage it responsibly.