How to Plant, Grow, and Care for Tansy

Commonly known as the tansy plant, Tanacetum vulgare can provide many benefits to your garden once you know how to grow and care for it. The yellow button-like flowers are simple, yet lovely, attracting pollinators while also being an insect repellent with a history of medicinal uses.

You can find Tanacetum vulgare growing in the wild in many places in North America. Some areas have labeled it as a noxious weed, but once you know how to prevent it from spreading, it really is an easy-to-grow perennial plant.

Follow this complete tansy guide to give this beautiful plant a home in your garden. 

Overview

Plant Type Perennial herb Family Asteraceae Genus Tanacetum Species Tanacetum vulgare	Native Area Temperate Europe and Asia Exposure Full sun to partial shade Height 1-5′ Watering Requirements Low, drought-tolerant	Pests & Diseases Aphids, spider mites, leaf spot, and powdery mildew Maintenance Low Soil Type Well-draining, rich Hardiness Zone 3-8

What is Tansy?

The tansy plant is known as the common tansy and its botanical name is Tanacetum vulgare. Other common names include bitter buttons, cow bitter, and golden buttons.

The derivation of the scientific name Tanacetum vulgare is interesting. Tanacetum comes from the Greek word athanasia, which means ‘no death’ or immortal. This is because once you dry the flowers, they last for many years, and the plant can last a long time as well. 

Native Area

This species is native to Asia and Europe, but it now grows everywhere in North America. It was brought to North America in the 1600s for its ornamental flowers. Since it spreads easily, it now grows in the wild and is known as a noxious weed in many areas. 

Characteristics

Common tansy (Tanacetum vulgare) is an herbaceous perennial that averages three to five feet tall and spreads twelve to eighteen inches. It reproduces by seeds or rhizomes, making it an aggressive grower that can easily become invasive. Tansy (Tanacetum vulgare) is often confused with the tansy ragwort (Senecio jacobaea) species, which is slightly more troublesome.

The foliage grows in a clump with multiple stems, giving the tansy plant a shrub-like appearance. The stem is reddish-brown, and the alternate leaves are fern-like. Bright yellow button-like flowers are arranged in a flat-topped cluster at the end of the stem. Crushing the flowers or foliage emits a distinct odor that is strong yet faintly like its cousin, yarrow. It makes a perfect insect repellent, but it will also attract native beneficial insects. 

Tanacetum vulgare is toxic, and gloves should be worn when handling it. It does, however, have medicinal qualities and was historically used to treat parasitic worms. Nowadays, it is considered a poisonous plant that can cause death if consumed in large quantities. Many varieties of garden flowers are toxic, so don’t let this deter you from planting them in your garden!

The common tansy grows well in containers or confined within garden beds, which helps prevent it from becoming a noxious weed in your garden. On a positive note, the common tansy will repel flies and other pest-like insects. At the same time, the golden yellow flower will attract parasitic wasps and pollinators such as bees, butterflies, and hummingbirds. Since the flower can bloom from July to September, it provides plenty of food for the bees. It is poisonous to animals, so don’t allow your cattle or sheep to graze within a tansy flower patch.

How To Grow

The tansy is one of the easiest plants to grow in your garden. You can grow tansy in a container or in the ground, depending on how much room you have and where you live. Gardeners in MD, MN, ID, OR, WA, WI, and WY should opt for container growing, or for an alternative as this plant is an invasive species in these states.

Light

Tansy prefers to grow in full sun but can tolerate partial shade. In order to keep the plants healthy, give them at least six hours of sunlight a day. This also helps them flower better. Do not place in heavy shade with low light, as they will not perform well.

Water

Once your tansy has become established, it is definitely drought-tolerant. This makes it the perfect choice to grow on the edges of your garden where it won’t get as much water as other plants.

The best time to water is in the morning before it gets too hot. Use a garden hose to water it deeply and allow the soil to dry between waterings. You can also opt for drip irrigation or soaker hoses.

During the summer months, water it more often for the first year. After that, it will only need a good soak once or twice a month depending on the temperature. Be careful not to overwater your tansy, or else the rhizomes won’t be able to establish themselves and could become weak. What’s nice about the common tansy is that it will survive in humid climates and dry climates as long as they aren’t extreme.  

Soil

Common tansy likes well-drained soil with a pH range of 4.8-7.5. This is a fairly large range, so it means the tansy can survive in a wide variety of soils. However, it is best to test the pH of your soil to make sure it’s not too alkaline or acidic. It will tolerate poor-quality soil, but for the healthiest plant, we recommend fertile garden soil amended with added compost.  

Temperature

It’s hardy to USDA zones 4-8 and tolerates zone 3 with some winter protection. Basically, it’s a hardy winter and summer perennial that will grow in a variety of temperatures. However, tansy does not thrive in prolonged, high heat, nor does it like extreme cold conditions. 

Fertilizer

Tansy does not require a high amount of fertilizer. Poor soils may need a general all-purpose fertilizer applied once or twice during the growing season.

In-ground plantings and containers will benefit from a topdressing of compost annually. There’s no need to add professionally formulated organic fertilizers as this plant grows just fine without it.

Generally, the more fertilizer you add, the more it will grow and expand. This can be seen as positive or negative, depending on your reasons for having this plant in your garden. 

Maintenance

This plant requires very little maintenance. When you grow tansy in a container, repot yearly using an all-purpose potting soil with good drainage. As mentioned earlier, it can grow in poor soil, but to have the healthiest tansy, it’s best to provide an ideal growing environment. 

Pruning

Cut the plant back every spring to keep the tansy cluster full and compact. Harvest flowers throughout the season and deadhead the plant when flowers fade to prevent seeds from spreading. Deadheading also encourages more flowers to bloom later in the season.

To delay or prevent blooming and spreading, cut back the foliage clusters in late summer. The seed heads will last through the winter, so if you don’t want it to become invasive, cut the dead flowers off before the cold season.

Take care when pruning and always wear gloves when working with tansy. It contains a naturally occurring compound called thujone that can cause contact dermatitis in those sensitive to it. 

Propagation

You can choose to plant seed of tansy to grow, or divide underground rhizomes in the fall. Start tansy seeds indoors six to eight weeks before the last frost, or sow them directly into the soil in the fall to allow the seed to cold stratify.

If you allow the common tansy flower go to seed, it will self-seed aggressively. You won’t need to worry about having enough of these flowers in your garden, but it will gradually spread and could easily take over.

Divide clusters of tansy in the fall as needed.

Common Problems

Even though tansy is an easy-to-grow plant for the everyday gardener, there are a few problems that are worth mentioning. Once you know what to watch for, you can prevent your common tansy from becoming unhealthy. 

Growing Problems

The biggest growing problem of the common tansy (Tanacetum vulgare) is that it can take over an area and become a noxious weed if not adequately controlled. When tansy plants grow in an optimal environment, they easily crowd out their neighbors.

Since their roots can grow deep, hand pulling is not the ideal way to get rid of them. As mentioned previously, it’s best to remove the seeds before they fall from the flower head. 

Pests

Thankfully, tansy plants aren’t bothered by many pests. Usually, they are the ones keeping the pesky bugs away. However, aphids and spider mites can become a concern in certain areas.

Aphids are insect pests found on many plants, and the tansy isn’t immune to them either. This pest lives under the fern-like leaves of the plant and feasts on all the juices. When you have a large infestation, it can stunt the growth and cause the leaves to turn yellow and fall off.

To rid your plant of these tiny bugs the natural way, blast them with a stream of water from a hose. You can use an insecticidal soap spray or a spray made from neem oil if water is not sufficient.  For severe infestations, consider the use of an organic pyrethrin spray.

Spider mites are an insect that feeds on the fluid within each plant cell. The only way to see the spider mite is with a magnifying glass, but to distinguish them from other mites and aphids, look for the presence of webs. They too like to make their home on the underside of the fern-like leaf and eventually, the leaves develop brown and white spots.

If they haven’t spread to neighboring tansy plants, you can remove the affected plant. Use the same treatment methods for mites that you would for aphids.

Diseases

Leaf spot and mildew are the most common diseases of the tansy. Overall, it is a resistant plant that is healthy and vibrant, but if one of these problems affects your plant, then it is best to treat it right away. 

It is easy to identify leaf spot because it’s exactly what it sounds like: small brown spots on the leaves of your plant. It is caused by fungal spores that multiply from too much moisture and/or not enough air circulating around the plants. You can treat this by pulling off the affected leaves and don’t get the leaves wet when watering.

Powdery mildew is another fungal infection that thrives in humid climates and can be exacerbated by poor air circulation. The infected leaves will display white powdery spots that will eventually cover the whole leaf and spread to other parts of the plant. When catching this early, remove affected leaves.

Frequently Asked Questions