Soap bush, variations in blue

Blue-colored soap bush flowers

Having blue flowers in the garden is rather uncommon. One of the advantages of the Ceanothus soap bush is that it comes in a range of blue hues from pastel blue to deep indigo.

Depending on the variety, soap bushes spread their blooming in an infinity of hues.

The often intense blue soap bushes revel in the spring sun, and hold on to their leaves for us over the winter, too.

In the wild

Since they grow very fast, soap bushes tend to have lush, dense stems. They are very easy to grow in temperate climates and show an excellent resistance to air pollution. Once they’ve set their root system up, drought is tolerated quite well, too, although having some moisture in the air helps.

  • Compact, tight-growing varieties are perfect for growing potted on a balcony, as are crawling vine-like species.
  • Most varieties will thrive without care when planted in the ground in any type of garden.

Soap bushes come in a variety of shapes: some sprawl along the ground, others sit quite upright and even form tree-like silhouettes. This wide range makes the plant very appealing to creative gardeners who can let their imagination run wild.

  • To make the most of them in a shrub bed, simply let them grow freely with enough space around your soap bushes that they may spread around.

Dressing up a pergola, fence or wall produces best results with taller varieties that you’ll tether to a lattice in a very sunny spot. When attached to a support structure, soap bushes can grow up to twice the height of normal bushes. Spreading, sprawling soap bushes are often used as ground cover on mounds of dirt and on rocky ground.

On the balcony

For a balcony, select a variety known to be suited to growing in pots. Your soap bush will amaze you and if you pair it with other easy shrubs like Russian sage, althea, Mexican orange tree, rosemary, Portugal laurel, lavender and bulbs and perennials.

  • Plant them in a garden box at least 16 inches (40 cm) deep in a blend of rose tree soil mix and sandy garden soil.
  • Avoid setting it up close to a very light-colored wall, so that leaves don’t “burn” to a crisp under the scorching summer sun.

Blue soap bush flowersAs much as possible, let the soap bush run its course as it grows to preserve its natural elegance: crawling types can dress a staircase or balcony edge quite well, and will dribble down tall earth mounds with ease. Match your soap bushes with shrubs that bear light-colored leaves, such as the katsura tree. Finish the arrangement off with a few bulbs or yellow-blooming perennials.


Image credits (edits Gaspard Lorthiois):
CC BY 2.0: Jerry Kirkhart, Denise Jay
CC BY-SA 2.0: Leonora Enking