What hardiness zones is Ocimum basilicum 'Purple Ruffles' suitable for?

Ocimum basilicum 'Purple Ruffles' is an annual herb in the Lamiaceae family, growing 18–24 inches (45–60 cm) tall and 12–18 inches (30–45 cm) wide with a bushy habit. An All-America Selections winner (1987). Leaves are 2–4 inches (5–10 cm) long, deeply ruffled and fringed at the margins, dark purple to burgundy — the ruffled texture and deep colour distinguish it from the smooth-leaved 'Dark Opal' purple basil. Flavour is mild, sweet basil with a slightly spicy, clove-like undertone — less pungent than green sweet basil. The purple colour is due to anthocyanin pigments; the colour fades when cooked (turns dark green-black) but remains vibrant when used raw or infused in vinegar. Stems are square (mint family characteristic), purple-tinged. Pink to lavender flower spikes appear from July onward — pinching delays flowering. Days to maturity: 65–75 from transplant. Germination is slower and less uniform than green basil — 60–70% germination rate vs 80–90% for green types. Requires warm conditions — minimum soil temperature 65°F (18°C) for germination, minimum air temperature 50°F (10°C) for growth. Susceptible to fusarium wilt, downy mildew (Peronospora belbahrii), and cold damage.

Native Range

Ocimum basilicum is native to tropical Asia, from India through Southeast Asia. 'Purple Ruffles' was developed in the United States and won an AAS award in 1987.

Suggested Uses

Ornamental and culinary — the deep purple ruffled leaves add colour contrast to herb gardens, container plantings, and borders. Infused in white vinegar to produce a vivid pink-purple herb vinegar. Used fresh in salads, as a garnish, and in pesto (produces a dark, earthy-coloured pesto). The colour fades in cooking — use raw for maximum visual impact.

How to Identify

Identified by the deeply ruffled, fringed, dark purple leaves on a bushy plant. Distinguished from 'Dark Opal' by the ruffled (not smooth) leaf margins. Distinguished from green basil by the purple colour and milder flavour.

Appearance

Size & Dimensions

Height1'6" - 2'

Width/Spread1' - 1'6"

Reaches mature size in approximately 1 years

Colors

Flower Colors

pink

purple

Foliage Colors

purple

Bloom Information

Bloom Period

~8 weeks

Summer

Pink to lavender flower spikes from July onward. Pinching delays flowering and extends the vegetative harvest period.

Detailed Descriptions

Flower Description

Pink to lavender

Foliage Description

Dark purple to burgundy, ruffled

Growing Conditions

Sun Requirements

Full Sun

Requires 6-10 hours of direct sunlight daily

• 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 - 7.0(Neutral)

357912

Soil Types

loam sand

Drainagewell drained

Water & Climate

Water Needs

Medium

Frost Tolerance

tender

Time to Maturity

65-75 days from transplant

Care & Maintenance

Care Guide

Start seed indoors 6–8 weeks before last frost at 70–75°F (21–24°C). Germination takes 7–14 days — slower and less uniform than green basil. Transplant after last frost when night temperatures stay above 50°F (10°C). Space 12–15 inches (30–38 cm) apart. Full sun (minimum 6 hours), fertile well-drained soil, pH 6.0–7.0. Water 1 inch (2.5 cm) per week. Pinch growing tips every 2–3 weeks to promote branching and delay flowering. In the Pacific Northwest, start indoors — direct sowing is unreliable due to cool soil temperatures.

Pruning

Pinch stem tips to the first set of leaves every 2–3 weeks to promote bushy branching and delay flowering. Once flower spikes appear, pinch them at the base to extend the harvest period. Harvest regularly — cutting stems back to a leaf pair promotes two new stems.