How to Grow Blue Vervain From Seed

Place a small amount of peat moss or sand in a small plastic resealable bag or small sealable container. Add water to dampen, but do not soak the peat moss. Place the blue vervain seeds in the peat moss, seal the bag, and place it in a refrigerator for 30 days.

Prepare a planting site for the blue vervain seeds when the soil has warmed to 60 degrees Fahrenheit. Find an area with full sun and well-drained soil. Break up the soil and add 2 to 4 inches of compost or other organic matter to enrich the planting bed. Incorporate the organic matter into the soil to a 6-inch depth.

Sow the blue vervain seeds at a depth twice the size of the seeds. Space the seeds 1 foot apart and then carefully dampen the soil without dislodging the seeds. Keep the soil moist, and watch for seedlings to appear in two to three weeks.

Continue to water the blue vervain plants as needed to maintain moist soil, especially when the plants are blooming. Supply a weekly deep watering if the plants get less than 1 inch of rainfall. Blue vervains are drought tolerant when established, but grow best without extended dry periods during the growing season.

Apply a fertilizer, such as 16-4-8, each year toward the end of spring. Cover the area around the blue vervain plants with 2 to 4 inches of mulch, and replace yearly as needed to maintain coverage.

Pinch the blue vervain plants to control growth and to encourage thicker plants during the growing season. Don’t prune the plants heavily until the following spring when new growth emerges.