Tansy in Zone 9B — Florida

Tansy is worth growing in your Florida garden for its insect-repelling properties and its cheerful, button-like yellow flowers that add a splash of color, especially when many other plants are struggling in the heat. It's incredibly low-maintenance and surprisingly easy to grow, even with our sandy soil. Plus, it's a natural way to keep unwanted pests away from your other crops.

Don't let the challenges of Florida gardening scare you off! While our humidity and occasional hurricanes can be tough, Tansy is well-suited to handle it. The long 344-day growing season gives you plenty of time to get it established and thriving.

Starting Tansy indoors isn't strictly necessary in Florida, given our long growing season, but it can give you a head start. If you want to get a jump, sow seeds indoors from mid-November through early December, about six weeks before you plan to transplant.

Use seed trays with a good seed-starting mix and keep them in a warm spot with plenty of light – a sunny windowsill or under grow lights works well. Bottom watering is key to prevent damping off; set the tray in a shallow dish of water and let the soil soak it up from the bottom. Remember our spring is reversed, so getting a head start indoors means you'll have bigger plants ready to go as soon as our weather starts to cool.

Transplant your Tansy seedlings outdoors from early January through early February. Before transplanting, harden them off by gradually exposing them to outdoor conditions for about a week. This helps them adjust to the sun and wind, preventing transplant shock.

When transplanting, space the plants 12-18 inches apart. Even though it's typically our dry season, keep an eye on the forecast. A cold snap or unexpected heavy rain can stress young transplants, so provide some protection if needed.

Direct sowing Tansy is easy in Florida, thanks to our long growing season. Sow seeds directly into the garden from early January through early October. The earlier you start, the bigger the plant will get.

Prepare the soil by loosening it and removing any weeds. Tansy isn't too fussy, but good drainage is always a plus in our humid climate. Sprinkle the seeds on the surface and lightly cover them with soil. Keep the soil consistently moist until the seedlings emerge. Space plants to 12-18 inches once they are established.

Tansy is incredibly drought-tolerant and thrives on neglect, which makes it perfect for Florida gardens. Overwatering is a much bigger problem than underwatering with this plant.

During our drier spring and fall months (late-March through early-May and late-September through early-November), check the soil moisture using the finger test. Stick your finger about 2 inches deep into the soil near the plant. If it feels dry, it's time to water. Aim for about 1 inch of water per week during these times. Once the summer rains start, you likely won't need to water at all.

Water at the base of the plant rather than overhead to help prevent fungal diseases, which are rampant in our humid summers. Signs of underwatering include wilting leaves, while yellowing leaves can indicate overwatering. A light layer of pine straw mulch can help retain moisture in the soil and suppress weeds, but don't overdo it, as Tansy prefers well-drained conditions.

Pruning Tansy is mostly about maintenance and preventing it from taking over. Deadhead the flowers regularly to prevent aggressive self-seeding, especially if you don't want it spreading throughout your garden.

Cut the plant back in the fall, after it has finished flowering. This helps keep it tidy and encourages new growth in the spring. Be aware that Tansy is very vigorous and can become invasive, so you might need to contain it by planting it in a pot or using barriers in the ground.

You can expect your first harvest of Tansy starting in late March and continuing through early January. The plant is ready to harvest when the button-like yellow flowers bloom in midsummer.

Harvest by cutting the stems with flowers and leaves. Tansy is primarily used as an insect repellent, so you can hang the cuttings indoors or place them in drawers and closets. Remember, Tansy is not for culinary use and can be toxic in large amounts, so keep it away from pets and children. As our first frost approaches in late December, you can cut back the plant and dry any remaining foliage for use as an insect repellent throughout the winter.

Here are the top two problems you might encounter with Tansy in your Florida garden:

Invasive Growth

• What it looks like: Tansy spreads rapidly, popping up in unwanted areas of your garden. It can quickly crowd out other plants.
• What causes it: Tansy is a vigorous grower and self-seeds readily. Our long growing season gives it ample time to spread.
• How to fix/prevent it: Plant Tansy in a container to restrict its roots. Deadhead flowers regularly to prevent self-seeding. Use physical barriers in the ground to contain its spread. Remove unwanted seedlings as soon as they appear.

Aphids

• What it looks like: Clusters of tiny soft-bodied insects (green, black, or white) on stems and leaf undersides. Sticky honeydew residue. Curled or distorted new growth.
• What causes it: Rapid-reproducing sap-sucking insects. Populations explode in warm weather. Ant colonies may farm them for honeydew.
• How to fix/prevent it: Strong water spray knocks them off. Encourage ladybugs and lacewings (natural predators). Insecticidal soap for heavy infestations. Neem oil works systemically. Avoid excess nitrogen fertilizer (it attracts them).

Florida Specific Challenges: Our hot, humid summers and wet-summer rainfall can exacerbate both of these problems. The humidity encourages aphid populations, and the long growing season allows Tansy to spread aggressively. Regular monitoring and preventative measures are key to keeping these issues under control.

Tansy can be a good companion plant for several crops in your Florida garden. It's known to repel certain insects, making it a useful addition to your vegetable patch.

Good companions include potatoes, squash, cucumbers, and raspberries. Tansy repels potato beetles, squash bugs, and cucumber beetles, protecting these crops from damage. It also deters raspberry beetles, helping to ensure a good harvest.

Avoid planting Tansy near brassicas (cabbage, broccoli, cauliflower) as it can attract cabbage moths.