Botanical Name: Lobelia erinus ‘Magadi™ Compact Blue Bay’

Common Name: Annual Lobelia

Hardiness Zone: Grown as an Annual in All Climates

Size: 6–8" Tall × 8–12" Spread

Growth Habit: Compact, Dense, Mounding Habit

Sunlight: Full Sun to Partial Shade (Best Performance in Morning Sun / Afternoon Shade)

Soil: Well-Drained, Moisture-Retentive Soil

Water Needs: Moderate; Prefers Consistent Moisture

Bloom Season: Spring through Early Summer (Extends Longer in Mild Climates)

Fertilizer: Light, Regular Feeding for Best Flowering

Features: Clear Sky-Blue Blooms with White Eyes, Compact Growth, Excellent Early-Season Performance

Uses: Containers, Edging, Window Boxes, Borders, Cool-Season Color

Patent: ✔ Patented

Propagation: ❌ Propagation Prohibited Without License

See our complete Lobelia Plant Guide for more in depth care details.

More About Lobelia ‘Magadi™ Compact Blue Bay’

Lobelia ‘Magadi™ Compact Blue Bay’ produces crisp blue flowers with bright white eyes, creating the fresh, classic look that has made lobelia a favorite in Spring containers. The blooms appear in dense clusters that sit right over the foliage, forming a strong layer of color rather than a loose or sprawling display. When the plant is in full bloom, the flowers almost blanket the foliage, giving the plant a very clean and polished appearance. The blue color is clear and bright, which makes it especially useful for brightening up container plantings early in the season. 

This variety was bred specifically for uniformity and control, which you can see immediately in its growth habit. The plant stays compact and well branched, forming a tidy mound rather than trailing heavily over the edges of containers. That neat structure makes it very easy to work into mixed plantings where you want color without losing definition in the overall design. It fills in nicely without overwhelming nearby plants, making it an excellent supporting plant in container combinations.

Why We Like It (Our Trials)

In our trials here in Zone 8a, ‘Compact Blue Bay’ has performed extremely well in Spring containers and cool season plantings. It establishes quickly, begins flowering early, and maintains a dense, compact shape throughout the season. Even as temperatures begin to warm, the plant tends to hold its structure rather than stretching or thinning out. One thing we consistently notice with this variety is how uniform the plants grow. 

In trays and container plantings, the plants develop very evenly, which creates a polished and professional look in finished containers. That consistency makes it especially valuable for gardeners who want their containers to look balanced and intentional. We especially appreciate how reliable it is in mixed containers. The clear blue color pairs beautifully with whites, yellows, soft pinks, and silvery foliage, adding contrast without overpowering the other plants.

Compact Blue Bay vs. Other Lobelia Varieties

Magadi™ Compact Blue Bay is all about control, offering a dense, mounded habit that stays neat and predictable throughout the season. Unlike trailing varieties such as Rift Blue and Rift Purple, Magadi does not spill aggressively, making it better suited for edging containers, small pots, and structured mixed plantings. Its classic blue color supports the design without overpowering neighboring plants.

When compared to Techno® Dark Blue, Magadi is slightly tighter and more formal, with less movement but more precision. It also contrasts with Hot® Purple by prioritizing shape over color intensity. For gardeners who want Lobelia to behave itself and maintain clean lines, Magadi Compact Blue Bay is the most disciplined option in the lineup.