Photo: "Purple Basil" by Jeangagnon · CC BY-SA 4.0

Herb · Annual-ornamental

Purple Basil

Open-pollinated · Lamiaceae

Grown primarily for dramatic dark purple foliage — striking visual contrast in gardens and garnishes. 'Dark Opal' (1962 AAS Winner) is the classic; 'Red Rubin' has more uniform coloring. Milder flavor than Genovese, 30-40% slower growth, lower total yield. Anthocyanin pigments break down when heated — best used raw. Good companion plant alongside green basils, marigolds, and peppers for visual drama.

At a Glance

Days to Maturity

70–85 days

Sun

6+ hours

6-8 hours

Spacing

12–15 "

Seed Start

6–8 weeks

before transplant

Container

Yes

1+ gallon pot

Height

1.2–1.7 ft

Zone Planting Guide

Your USDA Zone:

Growing Guide

Germination

Germination Time 5–14 days

Optimal Temp 80°F

Seed Depth 0.25"

Transplanting

Min Soil Temp 70°F

Harden Off 7 days

Watering

Weekly Water 1–1.5 "

Needs Consistent

Method Base watering.

Soil

pH Range 6–7

Soil Type Rich, moist, well-drained

Resilience

Heat: Moderate Cold: Very-low Drought: Low

Common Problems

basil-downy-mildew

Cause: Same as Genovese.

Prevention: Standard practices.

low-productivity

Cause: 30-40% less leaf yield than Genovese. Not a disease — inherent trait.

Prevention: Set expectations. Grow for beauty + garnish, not bulk harvest.

Nutrition

Feeding Intensity Moderate feeder

Recommended Recipes Compost tea

Harvest

Dark purple leaves, mature size. Best used fresh — color fades when cooked.

Storage 5 days — Stems in water on counter.

Companion Planting

Good Companions

Genovese basil Visual contrast — dark purple next to bright green.

French marigold Color palette companion.

Avoid Planting Near

Common sage Different water needs.

Sources

reference AAS — Dark Opal (1962 Winner) seed_catalog Johnny's Selected Seeds

More Herbs

Purple Basil Planting Dates by Zone

Planting dates for Purple Basil vary by USDA hardiness zone. Select your zone below for frost dates, start-indoors timing, and a full monthly planting calendar.

Zone 5A Zone 5B Zone 6A Zone 6B Zone 7A Zone 7B Zone 8A Zone 8B Zone 9A Zone 9B

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