Tansy in Zone 7B — Texas

Tansy is a worthwhile addition to any Texas garden, not for eating, but for its beauty and incredible insect-repelling properties. Imagine strolling through your garden, practically mosquito-free thanks to this plant! Plus, it's super easy to grow here, offering a lot of satisfaction for minimal effort.

Sure, gardening in Texas comes with its own set of challenges: the brutal Texas heat, unpredictable weather, and the occasional drought. But with Tansy, proper timing and minimal care will have you enjoying its benefits throughout our long 255-day growing season.

Starting Tansy indoors isn't really necessary here in Texas, given our long growing season, but it's an option if you want a head start. Begin in early to late January, about six weeks before the last average frost date.

Use seed trays filled with a good seed-starting mix, and keep them warm and consistently moist. Bottom watering is a great way to keep the soil evenly damp without disturbing the tiny seeds; just set the tray in a shallow pan of water until the top of the soil is moist. Since spring comes early here, indoor starts will give you a jump on the season.

Transplant your Tansy seedlings outdoors in late February through late March. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week.

Choose a spot with full sun to partial shade and space the plants 12-18 inches apart. Keep an eye on the weather, as we can still get some unpredictable freezes that time of year, so be ready to cover your young plants if needed.

Direct sowing Tansy is the easiest method for Texas gardeners. Sow seeds directly into the garden from late February through late August.

Prepare the soil by loosening it and removing any weeds. Since Tansy isn’t picky, just make sure the soil temperature is consistently above 60°F. Sow seeds thinly and cover lightly with soil, spacing for mature plants is 12-18 inches.

Tansy is incredibly drought-tolerant, practically thriving on neglect, which makes it perfect for Texas gardens. Overwatering and over-fertilizing can actually make it more aggressive.

During the spring and fall, when temperatures are milder and rainfall is more likely, you probably won't need to water it much at all unless we're in a dry spell. In the heat of the summer, especially if rainfall is scarce (as it often is), check the soil moisture with the "finger test"—stick your finger about two inches deep into the soil. If it feels dry, give your Tansy a good watering, about 1 inch of water per week.

Water at the base of the plant to avoid wetting the foliage, especially with our variable humidity, which helps prevent fungal diseases. Signs of underwatering include wilting or drooping leaves, while overwatering can lead to yellowing leaves and root rot. Mulching around the base of the plant with a layer of organic matter like shredded bark can help retain moisture in our hot climate and suppress weeds.

Pruning Tansy is mainly about managing its spread and keeping it tidy. Deadhead the spent flowers to prevent it from aggressively self-seeding all over your garden.

Throughout the growing season, you can lightly trim it to maintain its shape. As the first frost approaches around mid- November, cut the plant back to the ground. This helps keep the plant tidy over the winter and encourages fresh growth in the spring.

You can expect your first harvest of Tansy from early May through late November, about 75 days after planting. The button-like yellow flowers will bloom midsummer, indicating it's ready to use as an insect repellent.

Harvest by snipping off the stems with flowers. Remember, Tansy is not for culinary use and can be toxic in large amounts, so stick to using it as a natural pest deterrent. To encourage continued production, harvest regularly. As the first frost approaches in mid- November, you can harvest the remaining foliage for drying and use throughout the winter.

Here are a couple of common problems you might encounter with Tansy in Texas:

Invasive Spread

• What it looks like: Tansy can quickly spread beyond its intended area, popping up in unwanted places in your garden.
• What causes it: Its vigorous growth habit and prolific self-seeding can lead to it becoming invasive, especially in our long growing season.
• How to fix/prevent it: Contain Tansy by planting it in pots or using underground barriers to prevent its roots from spreading. Deadhead spent flowers regularly to reduce self-seeding.

Aphids

• What it looks like: Clusters of tiny, soft-bodied insects (green, black, or white) on stems and leaf undersides. You might also notice a sticky honeydew residue and curled or distorted new growth.
• What causes it: These sap-sucking insects thrive in warm weather and can rapidly reproduce, especially if there's excessive nitrogen in the soil. Ant colonies may also farm them for honeydew.
• How to fix/prevent it: Knock them off with a strong spray of water. Encourage natural predators like ladybugs and lacewings. For heavy infestations, use insecticidal soap or neem oil. Avoid over-fertilizing with nitrogen-rich fertilizers.

Texas Specific Challenges: The hot-to-extreme heat and variable humidity of Texas can stress Tansy, making it more susceptible to aphids. Unpredictable rainfall patterns can also affect its growth, so it's essential to monitor soil moisture and adjust watering accordingly.

Tansy makes a great companion plant for several vegetables and fruits in your Texas garden. It helps deter pests from potatoes, squash, and cucumbers, which can struggle in our hot climate. It also benefits raspberries by repelling certain insects that target them.

Avoid planting Tansy near brassicas like cabbage or kale, as it can inhibit their growth.