Tall verbena, with its vibrant colors and long blooming season, is a popular choice for gardens and landscapes. Growing it from seed offers a rewarding experience and allows for greater variety and cost savings compared to buying established plants. This guide covers the essentials of successfully growing tall verbena from seed, ensuring a flourishing display in your garden.
Understanding Tall Verbena
Before we delve into the specifics of seed germination and plant care, let's understand the characteristics of tall verbena (often referred to as Verbena bonariensis). This plant is known for its:
- Height: As the name suggests, it can reach impressive heights, adding vertical interest to your garden.
- Blooming period: Expect a long and prolific blooming season, usually from summer well into autumn.
- Attractiveness to pollinators: Tall verbena is a magnet for bees, butterflies, and other beneficial insects.
- Low-maintenance nature: Once established, it requires minimal care.
Sowing Tall Verbena Seeds: A Step-by-Step Guide
The success of growing tall verbena from seed hinges on proper sowing techniques. Here's a detailed guide:
1. Timing is Key: When to Sow
Tall verbena seeds can be sown directly outdoors after the last frost, typically in spring. Alternatively, starting seeds indoors 6-8 weeks before the last frost allows for an earlier bloom.
2. Choosing the Right Medium: Soil and Containers
Use a well-draining seed-starting mix. Avoid using garden soil, as it can be too dense and retain too much moisture, potentially leading to damping-off (a fungal disease that kills seedlings). Seed trays or small pots work well.
3. Sowing the Seeds: Technique and Depth
- Scattering: Sprinkle the seeds evenly over the surface of the seed-starting mix.
- Covering: Lightly cover the seeds with a thin layer of the mix – no more than 1/8 inch.
- Watering: Gently water the seeds using a fine mist spray to avoid dislodging them.
4. Providing Ideal Conditions: Light and Temperature
Place the seed trays in a warm location (around 70-75°F) with bright, indirect light. Direct sunlight can scorch delicate seedlings.
5. Maintaining Moisture: Watering and Humidity
Keep the soil consistently moist but not soggy. Use a spray bottle to water gently, ensuring even moisture distribution. High humidity can also aid germination. You can create a humid environment by covering the tray with a plastic dome or covering the tray with clear plastic wrap. Remove the covering once the seeds have germinated.
Transplanting Seedlings and Aftercare
1. Hardening Off Seedlings
Before transplanting outdoors, gradually acclimate the seedlings to outdoor conditions. This process, called hardening off, helps them withstand the harsher elements. Start by placing them outside for a few hours each day, gradually increasing the duration until they can stay outside full-time.
2. Choosing the Right Location: Sunlight and Soil
Tall verbena thrives in full sun to partial shade. Choose a location with well-drained soil. Amend heavy clay soils with organic matter to improve drainage.
3. Transplanting: Spacing and Depth
Space the seedlings approximately 12-18 inches apart to allow for proper growth. Plant them at the same depth they were growing in their containers.
4. Ongoing Care: Watering, Fertilizing, and Deadheading
Water regularly, especially during dry periods. A balanced, slow-release fertilizer can be applied in spring. Regular deadheading (removing spent flowers) encourages continuous blooming.
Troubleshooting Common Problems
- Poor Germination: Check for proper sowing depth, moisture levels, and temperature.
- Leggy Seedlings: This indicates insufficient light. Move seedlings closer to a light source or supplement with grow lights.
- Fungal Diseases: Ensure good air circulation and avoid overwatering.
By following these guidelines, you'll be well on your way to cultivating a beautiful and vibrant display of tall verbena in your garden. Remember that patience and observation are key to successful gardening. Happy growing!
