Botanical Name: Lobularia maritima ‘Stream™ Compact Purple’

Common Name: Sweet Alyssum

Hardiness Zone: Grown as an Annual in Most Climates (Perennial in USDA Zones 9–11)

Size: 4–6" Tall × 8–12" Spread

Growth Habit: Compact, Dense, Mounding Habit

Sunlight: Full Sun to Partial Shade (Best Performance in Cooler Weather)

Soil: Well-Drained Soil; Adapts to Average Garden Conditions

Water Needs: Low to Moderate; Drought Tolerant Once Established

Bloom Season: Early Spring through Summer (Excellent Heat Tolerance for Alyssum)

Fertilizer: Light Feeding as Needed

Features: Rich Purple Blooms, Compact Form, Improved Heat Tolerance, Lightly Fragrant

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

Patent: ✔ Patented

Propagation: ❌ Propagation Prohibited Without License

More About Lobularia ‘Stream™ Compact Purple’

Lobularia Stream™ Compact Purple is a refined Sweet Alyssum selection that focuses on structure and consistency rather than aggressive spreading growth. The plant produces rich purple flower clusters that sit closely together across the top of the foliage, creating a dense layer of color that feels intentional and polished. I like this variety when I want Alyssum color but do not want the plant wandering too far outside its space. The compact habit keeps the plant contained while still allowing the flowers to create a noticeable visual presence in containers and garden beds. The blooms carry that familiar honey-like fragrance that Lobularia is known for, which becomes noticeable when the plants warm in the Spring sun.

What really sets Stream™ Compact Purple apart is how controlled the growth remains compared to older Alyssum varieties. Traditional Lobularia often spreads widely and can become loose or uneven as the season progresses, but this variety was bred to stay tighter and more uniform. That makes it especially useful for edging pathways, lining the front of planting beds, or tucking neatly into smaller containers. I often think of it as a “precision Alyssum” because it fills its space without overwhelming neighboring plants. The deep purple tone also works beautifully when paired with whites, yellows, or soft blues, creating containers with strong contrast and depth. Because the plant stays compact, the flowers appear more concentrated and visually bold than on larger spreading varieties. 

Why We Like It (Our Trials)

In our trials here in Upstate South Carolina, Lobularia Stream™ Compact Purple has proven to be one of the most consistent compact Alyssum varieties we grow. The plants establish quickly during the cool conditions of early Spring and begin flowering shortly after planting. What impressed us most was how well the plants held their shape as they matured. Instead of stretching or opening up, the branching stays tight and balanced, allowing the plant to maintain its neat mound throughout the season. Even as temperatures begin warming later in Spring, the flowers remain dense across the plant. 

Another reason we continue growing this variety is how useful the scale of the plant is in container design. Larger varieties sometimes spill too aggressively, but Stream™ Compact Purple stays contained and allows other plants in the container to remain visible. I often recommend it when someone wants the fragrance and texture of Alyssum without the plant dominating the arrangement. The tight growth also makes it very effective along the edges of garden beds where a clean border of flowers is desired. For gardeners looking for a compact Lobularia that delivers strong color, controlled growth, and dependable performance, Stream™ Compact Purple has been an excellent performer in our trials.

Stream™ Compact Purple vs. Other Sweet Alyssum

Within the Stream™ Series, ‘Compact Purple’ delivers the strongest color while maintaining a tight, disciplined habit. Compared to Compact White, it provides more contrast, and compared to Compact Rose, it offers richer saturation. Compact Purple also holds its color more consistently in warmer conditions than Compact Rose or White. However, all varieties stay low and uniform with minimal maintenance.

Compared to Yolo Purple, it is smaller and more rigid in form. This makes it especially well suited for edging, window boxes, and designs where precise spacing and uniformity matter. Against Easy Breezy™ Purple, it lacks trailing but excels in control. Among purple Sweet Alyssum, Compact Purple is ideal for clean, modern plantings. Gardeners appreciate Stream™ Compact Purple for reliable color without sprawl.