Ocimum basilicum.
The basil par excellence — the basil of classical Italian cooking, and the variety used to make authentic pesto alla genovese, that emerald-green condiment born in the Genoa region (Genova in Italian) that Italy now protects under a designation of origin (Basilico Genovese DOP). But basil's history is far older and far broader: the plant is native to India, where it has been cultivated for about 5,000 years, and holds particular religious importance in the Hindu tradition (under a related species, Ocimum tenuiflorum, the sacred tulsi).
Its name comes from the Greek basilikos, meaning "royal" or "of the king," derived from basileus, "king" — probably because it was used in royal anointings and the perfumed baths of Byzantine kings. The Greeks and Romans saw it as an ambiguous plant, both beneficial and unsettling; in certain contemporary Greek Orthodox churches it is still among the blessed herbs. In the Middle Ages it is one of the herbs of Charlemagne's Capitulare De Villis (c. 800), which ordered its cultivation in every garden of the royal estates.
A compact, well-held plant 60-75 cm tall, forming a dense rounded crown of broad oval leaves in bright slightly glossy green, lightly bullate on the surface — it is this precise variety, with its large tender leaves and absence of bitterness, that the Italian pesto industry has selected over generations. Exceptional aroma, particularly rich in aromatic compounds (linalool, eucalyptol, eugenol) that give it simultaneous notes of clove, anise, mint and lemon — the most complex and rounded profile among the basils.
Obviously, first and foremost the pesto basil: fresh leaves crushed in a mortar (never in a blender, which oxidizes the chlorophyll and turns it brown and bitter) with garlic, sea salt, pine nuts, pecorino sardo, Parmesan and extra-virgin olive oil — the colour must stay a vibrant bright green, and the sauce a little grainy, never smooth like a purée. But also: whole leaves in caprese with mozzarella di bufala and tomatoes; scattered fresh onto pizza margherita after baking; added at the end of cooking to a tomato sauce; infused with lemon and honey; or simply a few fresh leaves slipped into a summer tomato-and-mozzarella sandwich. A traditional garden companion to tomatoes — the pairing is as happy on the plate as it is in the bed.
Grower's tip: Basil is a heat-loving plant that hates cold — a plant exposed even to 8 °C can turn black and lose its leaves within hours. Start indoors 6-8 weeks before last frost, at 22-25 °C, ideally on a heat mat. Transplant only once nights have stabilized above 12 °C — in Québec, early-to-mid June depending on the region. Keep watering regular (don't let it dry out), but avoid water on the leaves in the evening, which promotes downy mildew (Peronospora belbahrii), a disease that has become very widespread in North America since the 2010s. To stimulate leaf production and delay flowering (the plant loses its aroma when it bolts), regularly pinch the tips of the main stems — the plant then branches laterally and stays productive longer. Harvest by cutting whole stems rather than picking leaf by leaf.
- Open-pollinated. Tender annual. Insect-pollinated; crosses readily with other Ocimum basilicum nearby (purple basil, lettuce-leaf basil, etc.) — isolate for seed saving.
- Height: 60-75 cm.
- Maturity: 65-75 days for first full-sized leaves.
- Exposure: full sun, warmth.
- Rich, well-drained, warm soil. Space plants 25-30 cm apart.
- Start indoors 6-8 weeks before last frost, at 22-25 °C. Transplant early-to-mid June once nights are above 12 °C.
