PL. —Ocimum basilicumBotanical illustration — drop image
Ocimum basilicum

Basil

SpringSummerFall
2a11bHardiness zone
Peak bloom windowZone 6b · frost-offset weeks
Winter
Not in bloom
Spring
Peak bloom
Summer
Peak bloom
Fall
Not in bloom
Peak bloom
In bloom
Background

Basil grown to flower is one of the best-kept secrets in the cutting garden. The tiny white blooms on long branching stems add a delicate filler that smells extraordinary in an arrangement. Start from seed indoors 6 weeks before last frost or direct sow when soil is warm. The key: pinch the central stem early and often to create a bushy plant with many flowering stems.

Care guide
SunFull sun — 6+ hours
WaterRegular; keep soil moist but not waterlogged
SoilRich, moist, well-draining
Spacing12–18 inches
Height12–24 inches
Zone2a – 11b
Direct sow
Seasonal tasks
summer
sowSuccession 5 — last full succession; will produce before frost
fall
watchBring indoors or harvest all before first frost — basil blackens overnight
Common problems

Fusarium wilt

Symptoms

Sudden wilting, brown streaks in stems, yellowing leaves. Affects sweet basil varieties most.

Treatment

No cure. Remove and destroy plants. Do not replant in the same spot for 3+ years. Choose resistant varieties.

Downy mildew

Symptoms

Yellowing on top of leaves with grey-purple fuzz underneath. Spreads rapidly in humid conditions.

Treatment

Remove affected leaves. Improve air circulation. Avoid overhead watering. Copper spray as preventive.