Ocimum basilicum.

Basil — basilikos in Greek, "royal" — has been cultivated for more than five thousand years, native to the tropical plains of India where it has always held a place of honour in cuisine, pharmacopoeia and religious rituals. The purple-leaved selection, on the other hand, is much more recent — the founding variety Dark Opal was developed at the University of Connecticut and released in 1962, opening the way for an entire family of ornamental basils in deep tints, from vibrant violet to nearly black purple.

More than pretty, it's flavourful — a classic basil base note, but with a perfume that's more anise, almost clove-studded, giving it a more marked presence in dishes. Magnificent fresh in a caprese salad where it plays contrasts with mozzarella and tomato, in a pesto that takes on a surprising eggplant tint, torn over pasta, slipped into Vietnamese spring rolls. And its secret superpower: soaked in white vinegar, it colours the liquid a brilliant ruby in a few days — the base of a magnificent homemade aromatic vinegar that makes superb gifts.

Grower's tip: Basil loves heat. Really. Its germination stalls below 18 °C, and a young plant that catches cold in early season stays stunted all summer, no matter what you do afterwards. Start indoors 6 to 8 weeks before last frost, on a heat mat if possible, and transplant only once nights have stabilized above 12 °C — early June in Québec, never before. Pinch the first flowers as soon as they appear: that pruning pushes the plant to branch and to double or triple its leaf production.

• Open-pollinated. Stable variety. Self-fertile but visited by bees, which can cause crossings with other basils nearby — isolate for seed saving.
• Height: 30 to 45 cm.
• Maturity: 75 to 85 days for full size; first usable leaves from 6 weeks.
• Exposure: full sun, sheltered from wind.
• Rich, well-drained soil, kept cool without excess. Space plants 25-30 cm apart.
• Indoor start 6 to 8 weeks before last frost. Transplant once all risk of cold is past and the soil is at 18 °C minimum.