Transform Your Hanging Baskets with Lobelia erinus ‘Sapphire’

Lobelia erinus ‘Sapphire’ is a trailing variety loved for its vibrant, deep blue flowers and lush green foliage. Perfect for hanging baskets, window boxes, and containers, it creates a stunning cascading effect, bringing a burst of colour to any outdoor space. With its profuse blooming habit, ‘Sapphire’ ensures a dazzling display throughout the summer months.

Growing Conditions

Lobelia erinus ‘Sapphire’ thrives in full sun to partial shade and prefers moist, well-drained soil. This half-hardy annual can tolerate cooler temperatures but is sensitive to frost. In the UK, it is best to plant outdoors after the last frost has passed.

Planting Guide

Sow seeds indoors 8–10 weeks before the last expected frost. Sow seeds on the surface of moist compost without covering them, as they require light for germination. Maintain a temperature of 18–24°C (65–75°F). Germination usually occurs within 10–21 days.

Once seedlings are large enough to handle, transplant them into individual pots. Harden off the plants by gradually acclimating them to outdoor conditions over 7–10 days before planting out. After the risk of frost has passed, plant lobelia in hanging baskets or containers filled with rich, moisture-retentive compost. Space plants approximately 10–15 cm (4–6 inches) apart to allow for full growth.

Care & Maintenance

Water regularly to keep the soil consistently moist but not waterlogged. Hanging baskets may require daily watering during hot, dry periods. Apply a balanced, water-soluble fertiliser every two weeks to encourage vigorous growth and abundant flowering. While lobelia is self-cleaning and doesn’t require deadheading, trimming back any straggly stems can keep the plant looking tidy and may extend its blooming period.

Flowering & Cut Flower Tips

Lobelia erinus ‘Sapphire’ blooms from late spring through early autumn. Although primarily used for its ornamental value in hanging baskets and containers, its delicate flowers can also be used as fillers in small floral arrangements. Harvest in the morning when flowers are fully open for the best vase life.

Garden Impact

This trailing lobelia attracts pollinators such as bees and butterflies, making it an excellent addition to wildlife-friendly gardens. Its intense blue flowers provide a striking contrast when paired with other summer blooms like petunias, geraniums, or marigolds, creating vibrant and dynamic displays.

Additional Notes

At the end of the season, remove spent plants and compost them. In milder regions, lobelia may self-seed, providing volunteer plants the following year.