How to Grow Calibrachoa from Seed: A Complete Guide

Calibrachoa, often called “Million Bells,” is a favorite among gardeners for its vibrant, bell-shaped flowers and trailing growth habit. These cheerful blooms are perfect for hanging baskets, containers, or garden beds, bringing a cascade of color throughout the growing season. While many gardeners purchase calibrachoa as nursery plants, growing them from seed is an affordable and rewarding way to enjoy these stunning flowers.

In this guide, we’ll walk you through the step-by-step process of growing calibrachoa from seed, including tips on seed selection, germination, and proper care.

Why Grow Calibrachoa from Seed?

Growing calibrachoa from seed offers several advantages:

1. Cost-Effectiveness: Seeds are more affordable than purchasing established plants.
2. Greater Variety: Seed catalogs often feature unique calibrachoa colors and patterns not commonly found in nurseries.
3. Satisfaction: Watching your plants grow from tiny seeds into lush, blooming specimens is incredibly rewarding.

However, calibrachoa seeds can be a bit tricky to work with due to their small size and specific germination requirements. With patience and attention to detail, you can successfully grow calibrachoa from seed.

Step 1: Choosing the Right Seeds

When selecting calibrachoa seeds, look for:

• High-Quality Seeds: Purchase from reputable suppliers to ensure good germination rates.
• Pelleted Seeds: Due to their small size, calibrachoa seeds are often sold as pelleted seeds, which are coated for easier handling and planting.
• Preferred Varieties: Decide on colors and patterns that suit your garden’s aesthetic. Popular options include vibrant pinks, purples, yellows, and bi-color varieties.

Step 2: Preparing for Seed Sowing

Timing is crucial when starting calibrachoa seeds. These plants take about 12–16 weeks from seed to bloom, so plan accordingly.

• Start Indoors: Begin sowing seeds indoors 10–12 weeks before the last expected frost date in your area.
• Choose Containers: Use seed trays, small pots, or cell packs with drainage holes.
• Prepare the Growing Medium: Use a light, well-draining seed-starting mix. Avoid heavy garden soil, as it can retain too much moisture and hinder germination.

Step 3: Sowing Calibrachoa Seeds

1. Moisten the Soil: Lightly moisten the seed-starting mix before planting. The soil should be damp but not waterlogged.
2. Sow the Seeds: Place one seed in each cell or pot. If using pelleted seeds, press them gently onto the soil surface without covering them. Calibrachoa seeds need light to germinate.
3. Cover and Label: Cover the trays with a clear plastic lid or plastic wrap to retain humidity. Label your trays with the seed variety and planting date.

Step 4: Germinating Calibrachoa Seeds

To ensure successful germination:

• Maintain Optimal Temperature: Keep the temperature between 70–75°F (21–24°C) for best results.
• Provide Light: Place the seed trays in a bright location, such as a south-facing window or under grow lights. Avoid direct sunlight, which can overheat the seeds.
• Monitor Humidity: Check the soil regularly and mist with water to keep it consistently moist. Remove the plastic cover once seedlings emerge to prevent fungal issues.

Germination typically takes 10–14 days, although it may vary depending on the seed variety and growing conditions.

Step 5: Caring for Calibrachoa Seedlings

Once the seeds have germinated, focus on nurturing the young seedlings:

1. Lighting: Provide 12–16 hours of light daily using grow lights or a bright windowsill. Insufficient light can lead to leggy growth.
2. Thinning: If multiple seedlings sprout in one cell, thin them by snipping the weaker seedlings at the base.
3. Watering: Water gently and consistently to keep the soil evenly moist. Avoid overwatering, which can lead to root rot.
4. Fertilizing: Once seedlings develop their first true leaves, begin feeding them with a diluted, balanced liquid fertilizer every two weeks.

Step 6: Transplanting Seedlings

As the seedlings grow stronger, they will need to be transplanted into larger pots or containers.

• Timing: Transplant when the seedlings have at least two sets of true leaves and the weather is warm enough.
• Prepare Containers: Use pots with drainage holes and a well-draining potting mix enriched with organic matter.
• Spacing: Space plants 6–12 inches apart if planting in garden beds or larger containers to allow room for growth.

Step 7: Hardening Off

Before moving your calibrachoa seedlings outdoors, they need to be hardened off to acclimate to outdoor conditions.

• Start Gradually: Place the seedlings outside in a sheltered location for a few hours each day, gradually increasing their time outdoors over 7–10 days.
• Protect from Extremes: Avoid exposing young plants to strong winds, heavy rain, or harsh sunlight during this transition period.

Step 8: Planting Outdoors

Once the risk of frost has passed and the seedlings are acclimated, it’s time to plant them outdoors.

• Choose the Right Spot: Select a location with full sun to partial shade and well-draining soil.
• Planting Depth: Plant seedlings at the same depth they were growing in their containers.
• Watering: Water thoroughly after planting to help the roots establish.

Step 9: Caring for Mature Calibrachoa Plants

To keep your calibrachoa plants healthy and blooming throughout the season, follow these care tips:

1. Watering: Calibrachoa prefers consistent moisture but does not tolerate soggy soil. Water deeply when the top inch of soil feels dry.
2. Fertilizing: Feed with a balanced, water-soluble fertilizer every 1–2 weeks to support continuous blooms.
3. Pruning: Pinch back leggy growth to encourage bushier plants and more flowers.
4. Deadheading: Remove spent blooms to promote new growth and maintain a tidy appearance.

Common Challenges and Solutions

1. Poor Germination

• Ensure seeds are fresh and not buried under soil.
• Maintain proper light and temperature during germination.

2. Leggy Seedlings

• Provide sufficient light and avoid overwatering.

3. Pests and Diseases

• Watch for aphids, spider mites, and powdery mildew. Treat with insecticidal soap or fungicides as needed.

Conclusion

Growing calibrachoa from seed may require patience and attention to detail, but the results are well worth the effort. By following these steps, you can enjoy a stunning display of Million Bells in your garden or patio. Whether cascading from a hanging basket or filling a garden bed with vibrant color, calibrachoa grown from seed will be a testament to your gardening skills and dedication. Snapdragon Seeds: Complete Guide for Thriving Blooms