Greater Knapweed (Centaurea scabiosa).

Greater Knapweed (Centaurea scabiosa) is a perennial flowering plant that is relatively easy to grow from seed. It is attractive to butterflies and other beneficial insects. Here are the steps to sow Greater Knapweed seeds:

1. **Timing**: The best time to sow seeds is in the late Summer or early Autumn, allowing them to germinate and establish themselves before Winter. However, you can also sow seeds in the spring if you wish.

2. **Preparation**: Start by preparing the planting site. Knapweed prefers well-drained soil in full sun or partial shade. It can tolerate a range of soil types from sandy to clay, but it does best in soil with moderate fertility. Remove any weeds or debris from the area.

3. **Sowing**: Scatter the seeds thinly over the prepared soil surface. Knapweed seeds do not require stratification but can be lightly raked into the soil to ensure good contact with the soil.

4. **Soil**: The seeds need a firm soil bed to germinate, so gently press the seeds into the soil. Do not bury them too deeply; a depth of 1/8 to 1/4 inch (3-6 mm) is sufficient.

5. **Watering**: Water the seeds thoroughly after sowing to moisten the soil. Keep the soil consistently moist, but not saturated, until the seedlings emerge. Once established, knapweed can tolerate some drought.

6. **Spacing**: Space the plants about 12-18 inches (30-45 cm) apart to allow for growth and good air circulation.

7. **Maintenance**: Keep the area weed-free while the knapweed is establishing itself. Once the seedlings are a few inches tall, you can begin to reduce watering to only when the soil is dry.

8. **Germination**: Germination typically occurs within 14-30 days. Keep an eye out for the small, hairy leaves of the seedlings.

9. **Transplanting**: If you are starting the seeds indoors, wait until the seedlings have at least two sets of true leaves before transplanting them outdoors in the spring, after the last frost date for your area.

10. **Care**: Once established, Greater Knapweed requires minimal care. It may benefit from a light application of balanced fertilizer in the spring, but it is generally not necessary. Deadheading spent flowers can encourage more blooming throughout the season.