What are the sun requirements for Ocimum basilicum 'Cardinal'?

Ocimum basilicum 'Cardinal' requires full sun.

How much water does Ocimum basilicum 'Cardinal' need?

Ocimum basilicum 'Cardinal' has moderate, consistent moisture water needs.

Annuals

Ocimum basilicum 'Cardinal'

Cardinal Basil

UnknownAsia

At a Glance

Typeannual

Habitcompact, bushy

Foliagedeciduous

Height12-18 inches

Width8-12 inches

Maturity0.17 years

Key Features

Attracts Pollinators

Attracts Butterflies

Fragrant (moderate)

Container Friendly

Maintenancemoderate

Overview

Ocimum basilicum 'Cardinal' is a compact, bushy annual herb that forms a dense mound of glossy, deep green foliage topped with striking cardinal-red flower spikes. The ovate leaves are typically 2-3 inches long with a smooth texture and emit the characteristic sweet, spicy basil fragrance when bruised. The plant produces dense terminal racemes of small tubular flowers that emerge bright red and gradually fade to burgundy, creating a dramatic display above the aromatic foliage. This cultivar is distinguished from other Ocimum basilicum varieties by its exceptionally vibrant red flowering spikes and more compact growth habit. The flowers are particularly attractive to pollinators and maintain their color for several weeks, making Ocimum basilicum 'Cardinal' both a functional culinary herb and an ornamental garden accent. The plant typically reaches maturity quickly and will continue producing flowers throughout the growing season if regularly harvested.

Native Range

Ocimum basilicum is native to tropical regions of central Africa and Southeast Asia, particularly areas of India, Thailand, and other parts of the Indian subcontinent where it has been cultivated for thousands of years.

Suggested Uses

Ocimum basilicum 'Cardinal' works well in ornamental containers, herb gardens, and mixed borders where its colorful flowers can serve as an accent plant. Excellent for cutting gardens as the red flower spikes make attractive additions to fresh arrangements. Suitable for window boxes and small space gardens due to its compact habit. Can be used in culinary applications like other basil varieties, though it's primarily grown for ornamental purposes.

How to Identify

Ocimum basilicum 'Cardinal' can be identified by its characteristic square stems typical of the mint family, opposite pairs of glossy green ovate leaves, and most distinctively, its bright cardinal-red flower spikes that rise above the foliage. The leaves emit a strong, sweet basil fragrance when touched, and the compact, mounded growth habit distinguishes it from taller basil varieties. The tubular flowers are arranged in dense terminal racemes and maintain their vibrant red color for extended periods.

Appearance

Size & Dimensions

Height1' - 1'6"

Width/Spread8" - 1'

Reaches mature size in approximately 0.17 years

Colors

Flower Colors

red

burgundy

Foliage Colors

green

Bloom Information

Bloom Period

SummerFall

mid-summer through fall

Detailed Descriptions

Flower Description

cardinal red to burgundy

Foliage Description

deep green, glossy

Growing Conditions

Sun Requirements

Full Sun

• Full Sun: 6+ hours of direct sunlight

• Partial Shade: 3-6 hours of direct sunlight

• Full Shade: Less than 3 hours of direct sunlight

Soil Requirements

pH Range6.0 - 7.5(Neutral)

357912

Drainage

well drained

Water & Climate

Water Needs

moderate, consistent moisture

Frost Tolerance

tender

Time to Maturity

8-10 weeks

Care & Maintenance

Care Guide

Ocimum basilicum 'Cardinal' requires warm conditions and should not be planted outdoors until soil temperatures reach at least 60°F and all danger of frost has passed. Provide consistent moisture but ensure good drainage, as basil is susceptible to root rot in waterlogged conditions. Feed every 2-3 weeks with a balanced, diluted fertilizer during the growing season. Pinch flower buds regularly to encourage continued leaf production, though this cultivar is grown specifically for its ornamental flowers. Protect from strong winds and provide afternoon shade in extremely hot climates.

Pruning

Ocimum basilicum 'Cardinal' benefits from regular pinching and harvesting to maintain bushy growth. Unlike culinary basil varieties, allow the distinctive red flower spikes to develop for ornamental value. Remove spent flowers to encourage continued blooming and prevent excessive self-seeding. Harvest leaves regularly by pinching just above a pair of leaves to encourage branching. Remove any yellowing or damaged foliage promptly to maintain plant health and appearance.

Maintenance Level

moderate

Container Growing

✓ Suitable for container growing

⚠️ Toxicity Warning

Ocimum basilicum 'Cardinal' is generally safe for humans and commonly used in cooking, though some individuals may experience skin irritation from handling the plant. The essential oils can be mildly toxic to cats and dogs in large quantities, though small amounts are typically not harmful.

Planting Guide

Planting Methods & Timing

Planting Method

both

Indoor Start

6 weeks before last frost

Direct Sow Timing

after last frost when soil is warm

Days to Maturity

55–70 days

Plant Spacing

8 inches

Companion Planting

Good Companions

tomatoes

peppers

oregano

marigolds

petunias

Avoid Planting With

fennel

rue

sage