Everyone likes basil, or I have yet to meet that person who does not. Basil (bay-zill to Americans, ba-zill to the British) is considered the king of herbs owing to its elevated status among them. Fittingly, the word “basil” is derived from the word basiliskos, which means “little king” in Greek and refers to a small, mysterious and venomous serpent, the basilisk, with a marking on its head that resembles a crown.
While diminutive in size, the quasi-mythical basilisk is extremely poisonous. According to the Roman naturalist Pliny the Elder, it could kill simply by fixing its gaze on its prey. In any event, a medicinal oil extracted from the plant we call basil supposedly proved itself as an antidote to basilisk venom and thus the plant’s name became intertwined with that of the little serpent.
Although all basil species are perennial in their native tropical lands, which stretch from central Africa to Southeast Asia, most of them are cold-sensitive and should be considered annuals when planted in our gardens.
Sweet basil is the most popular and widely planted basil species (Ocimum basilicum) and includes more than 60 cultivars. It typically has shiny lime-green leaves and grows well in full to partial sun. The challenge of growing sweet basil has to do with its requirements for both excellent sunlight and moist soil. Most of the sun-loving plants that we grow in Southern California are from Mediterranean climates like our own. They are not particularly thirsty and most do well, once established and well-mulched, with no more than one weekly soaking even in the hottest weather. So basil has to be given its own corner in the garden where it can be monitored daily for its water needs. Among sweet basil cultivars whose names describe their foliar scent, shape or color, there are anise, cinnamon, lettuce leaf, and purple basil.
I recently planted an intriguing sweet basil known as Everleaf Thai Towers. This columnar cultivar with a strong vertical growth habit really does tower over other basils, reaching a height of three feet. Other than height, the advantage it has compared to other basils is its later flowering period. Regardless of the cultivar, once sweet basil begins to flower, its aroma (or flavor) turns bitter. Everleaf Thai Towers allow you to harvest leaves, whose licorice scent remains uncompromised, for up to three months longer than other sweet basil types.
If I had to single out a single plant to recommend for every Southern California garden, African blue basil, an incredible perennial, would be it. Imagine acquiring a plant in the spring that is only a few inches tall and then seeing it grow into a gorgeous four-foot-tall specimen by midsummer, eventually reaching more than five feet in height.
African blue basil grows equally well in sun or light shade. It requires a bare minimum of water. It will grace your garden for several years at least although, like sweet basil, it is easily propagated from cuttings so that you will have its clones forever if you choose. Not as culinarily enticing as sweet basil because of its heavier camphor component, you can still use its leaves to make pesto, to sprinkle over roasted potatoes and to flavor drinks and salads.
Finally, lemon basil (Ocimum x africanum) deserves mention. Its powerful lemon scent spices up Asian cuisine. Lemon basil grows quickly, so frequent harvest of its leaves is essential to ensure that it continues to produce leaves, preventing it from going to seed, at which point the foliage becomes dry, leathery, and useless.
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 production.
But due to African basil’s sterile status, flowers grow far more abundantly than on other basils and its flowering shoots can reach more than eighteen inches in length. When in full bloom, these shoots are quite a sight to see. Most often, the cultivar you encounter has pink flowers but a stunning cultivar with deep violet blooms is also occasionally seen.
African blue 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.
The creation of African blue basil, a hybrid, was accidental. One parent is a stout woody shrub that grows more than six feet tall with foliage that is heavily laced with camphor. Its other parent is a common variety of sweet basil with purple or dark opal foliage. An American herbalist was growing these two plants side by side when suddenly a new type of basil seedling sprouted nearby, which turned out to be a hybrid of the other two. Although it blooms throughout the year, African blue basil flowers most heavily in the fall.
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Do you have a problem with raccoons digging up your lawn or with crows pecking at and putting holes in it? The reason for this disfiguring activity has to do with a search for beetle larvae, otherwise known as grubs. Generally speaking, grubs grow in moist and shady lawn areas. To remedy this predicament, spray Neem oil where the raccoons and crows are doing their damage. Neem oil is really a kind of miracle solution for garden pest problems. Derived from the seeds of the tropical neem tree, Neem oil is effective both as an insecticide and as a fungicide.
Neem oil is not a contact insecticide, meaning you do not spray it on the offending pests but rather on the plants that these pests consume. You spray the victimized host plants and the offending insects, upon ingesting the oil, suffer a hormonal breakdown so that they lose the ability or the desire to eat and mate. If the affected insects do mate, their eggs may not hatch and, if they do, the offspring do not develop normally. At the same time, Neem oil does not bother honeybees and most beneficial insects since they do not ingest it. It is harmless to earthworms, pets and people and may be sprayed freely on edible plants. As a fungicide, it can be used both to prevent fungus from visiting susceptible plants and as a contact spray on existing fungi such as powdery mildew, rust, black spot, and anthracnose.
Tip of the Week: Basil is one of the easiest plants to propagate and so you can easily have a multitude of it growing year round. Cut four- to six-inch terminal shoots from plants that have not yet flowered. If you should see flower buds on shoots, remove them so that all the plant’s energy will be channeled into producing roots. Place shoots in water, making sure to remove any bottom leaves that would otherwise be submerged. At this time of year, you should see roots begin to emerge within two weeks. In fall and winter, the process will take longer. When a healthy clump of roots is visible, transplant shoots into the ground or pots containing standard soil mix. Be aware that basil needs good light to grow. A window sill is fine as long as that location benefits from eight hours of direct light each day. Basil is cold sensitive so plants should be moved indoors by mid-November unless you live in a balmy coastal location.
Please send questions, comments, and photos to joshua@perfectplants.com.