The color of a glaciers underbelly, Elvis’s chosen shade for suede shoes, and the dye that made Levi Strauss’s jeans a namesake, today is all about the cool, hue that’s blue. We’re talking about Midnight Blue lobelia, Blue plumbago, and Blue Daze.

Lobelia are annuals that like cool weather like fall.

Lobelia

 

Midnight blue lobelia, known for its striking and rich cobalt flowers, brings a touch of elegance to any garden with its lush, cascading blooms. In San Antonio, Texas, this plant thrives best in AM sun and PM shade, ensuring it receives protection from harsh sun but also enough light to encourage prolific flowering. Ideally, it should be planted in well-draining soil that remains consistently moist, as lobelia does not tolerate drought conditions well.

 

At maturity, this annual only reaches heights of about 12 inches in height, making it an excellent choice for front borders, hanging baskets, and containers where its vivid blue flowers can cascade. Its intense blue hue is a standout in any landscape, providing a cool contrast to warmer-colored plants. Lobelia is generally used as a transitional annual here in San Antonio, as it likes the cooler weather of fall and early winter but doesn’t tolerate frost. There aren’t too many true-blues out there and these are a hot commodity when they hit the nursery tables.

Plumbago

Blue Plumbago

 

Blue plumbago, or Plumbago auriculata, is a perennial shrub that dazzles with its profuse, large, clusters of sky-blue flowers. Plumbago creates a soft ambiance in gardens. In San Antonio, this perennial thrives in full sun but can tolerate partial shade, making it versatile for various landscape positions. Blue plumbago needs well-draining soil and performs best with moderate watering, although after a few years of establishment, I have found that its drought tolerance increases. Still, it will appreciate a good soak during the hottest and driest of times and will generally reward you with another flush of blooms.

 

At maturity, blue plumbago usually grows an average of 3 feet tall and 3-4 feet wide, forming a sprawling bush that can be used as a hedge or background plant in flower beds. Blue plumbago is semi-hardy, tolerating light frosts, but it will generally die back in winter. Prune to the ground in late winter/early spring and watch it return with a vengeance. While not alway listed on pollinator lists, my plumbago always has the Giant Swallowtails sipping from it flower clusters. This is one of my favorite plants due to it color first, and its resilience and reliability in my garden.

Blue Daze flowers

Blue Daze

 

Blue daze, or Evolvulus glomeratus, is a charming groundcover-like plant that adds heat tolerance and charm to annual garden beds and container gardens. Known for its low-growing habit, this plant reaches only about 6-12 inches in height, spreading to create a dense mat of silvery-green, fuzzy foliage punctuated by brilliant blue flowers. To add to its adorable characteristics, the blue flowers close during the evening as if tucking in to catch some z’s, and “awaken”, or open, when the sun rises to greet the morning.

 

Perfect for San Antonio’s climate, blue daze thrives in full sun and well-drained soil, requiring regular watering to become established but develops more drought-tolerance once mature. It’s an ideal choice for edging, rock gardens, or as a filler between taller plants, where its vivid blue flowers can shine. I particularly love using blue daze as a “spiller” in a red, white and blue thriller, filler, spiller container arrangement. The flowers have a brilliant blue hue that captures attention and complements a wide variety of garden palettes. Blue daze is not frost-hardy and will need protection during cold snaps, making it a prime candidate for container planting so you can easily move it indoors when the temps take a dive.

Join us next week for an easy color to celebrate when it comes to plants, green!

~The Happy Gardener, Lisa Mulroy