African blue basil (Ocimum ‘African Blue’)

“If it sounds too good to be true, it probably is.”
This well-worn adage has near universal application, except in the case of African blue basil.
Imagine acquiring a plant in the spring that is only a few inches tall and then seeing it grow into a gorgeous 4-foot-tall specimen by midsummer, eventually growing to more than 5 feet.
African blue basil grows equally well in sun or light shade. It requires a bare minimum of water. It is a perennial and will grace your garden for several years at least. You can use it make pesto, to sprinkle over roasted potatoes and to flavor drinks and salads.
To its horticultural advantage, African blue basil (Ocimum kilimandscharicum x basilicum ‘Dark Opal’) is a sterile, seedless hybrid. In most plants, flower production is limited by seed production; the presence of seeds and the elevated input of energy required for their development halts flower bud proliferation.
But due to African basil’s sterile status, flowers grow far more abundantly than on either of its parents; flower shoots can reach more than 18 inches long. And its lack of seeds is no obstacle to propagation. Detach African basil shoots and place their bottom few inches in a vase of water. Roots will begin to grow out from these submerged shoot ends in a short time.
African basil performs well in all sorts of cut flower arrangements, both in vases and in dry bouquets. It is a garden designer’s dream on account of its dark foliage, effectively showing off surrounding flowers, whether orange, yellow or pink. There are also reports of its avoidance by deer, most likely due to the concentrated camphor in its leaves.
African basil is a most curious plant, starting with its accidental hybrid origins. Its African parent is a stout woody shrub that grows more than 6 feet tall with foliage that is heavily laced with camphor. Its other parent is a common variety of garden sage with purple — or “dark opal” — foliage. An American herbalist was growing these two plants side by side when suddenly a new type of basil began to grow nearby, a hybrid of the other two plants.
Turk’s cap
Turk’s cap (Malvaviscus drummondii) is famous for being the reluctant or sleepy scarlet hibiscus. It always appears just about to open but never does. Yet Turk’s cap is tougher than its hibiscus cousin. I have seen it growing in the near absence of summer irrigation. It is a semi-arboreal, yet sprawling plant that can serve functions as diverse as an amorphous background hedge or, on a slope, as a tall, undulating ground cover.
Yellow bird of paradise
If you are in search of a truly tough yet exotic looking plant that you will never worry about once it establishes itself, consider crimson threadflower, more commonly known as yellow bird of paradise (Caesalpinia gilliesii). This bird of paradise is in the legume family, with no relationship to the ever-present orange bird of paradise (Strelitzia reginae).
Yellow bird of paradise flowers are each graced with 10 long red stamens, providing a plumed, avian aspect. Foliage consists of delicate, bipinnate foliage consisting of a plethora of tiny, feathery leaflets.
Delphinium and alyssum
Dwarf blue delphinium (Delphinium grandiflora) is a special plant, owing to its true blue flowers, small stature and self-sowing capacity. I saw it recently in a flower bed with sweet alyssum (Lobularia maritima).
Although sweet alyssum is nearly always utilized in flower beds for edging or as a filler in between upright annuals, it makes a wonderful subject for hanging baskets and planter boxes. Not long ago, I saw a large, foamy mass of sweet alyssum, a virtually perfect hemisphere of it, spilling out of a window box; it nearly took my breath away.