Holy basil Ocimum tenuiflorum
Holy basil (Ocimum tenuiflorum) is an annual herb in the Lamiaceae family, native to Tropical Asia (Indian subcontinent). It grows 30–60 cm (12–24 in) tall and 30–45 cm (12–18 in) wide, wants full sun and moderate water, and is hardy to about 2 °C (36 °F). Space plants about 30 cm (12 in) apart.
Plan Holy basil in your garden →
Free. Draw your beds, then watch it grow through the year in 2D and 3D.
Holy basil at a glance
| Type | Annual herb |
|---|---|
| Family | Lamiaceae |
| Mature height | 30–60 cm (12–24 in) |
| Mature spread | 30–45 cm (12–18 in) |
| Spacing | 30 cm (12 in) centre to centre |
| Sun | Full sun, at least 6 h of direct sun a day |
| Water | Moderate; drought tolerance low, waterlogging tolerance none |
| Soil pH | 5.8–7.5 |
| Cold hardiness | About 2 °C (36 °F) once established (roughly USDA zone 10) |
| Heat stress | Likely above about 36 °C (97 °F) |
| Flowering | about 9–13 weeks after planting, for 9–14 weeks |
| Days to maturity | About 80 days from planting |
| Wind tolerance | Low |
| Pollinator value | High |
| Edible | Yes: leaves, flowering tops |
| Native to | Tropical Asia (Indian subcontinent) |
| Common in gardens of | 🇹🇭 Thailand, 🇸🇬 Singapore, 🇮🇳 India |
Is Holy basil toxic?
- People: not known to be toxic
- Cats: not known to be toxic
- Dogs: not known to be toxic
Related basil is listed as non-toxic by ASPCA; holy basil itself is not separately listed.
If a child or pet may have eaten part of a plant, call a poison centre or vet straight away.
Companion planting: what to grow with Holy basil
No well-documented helpful pairing. Group it with plants that like full sun and moderate water.
See Holy basil in a botanical garden
It grows in this sample garden, which you can walk through in 3D:
- Gardens by the Bay (8 plants)
Questions about Holy basil
- How far apart should I plant Holy basil?
- About 30 cm (12 in) apart, centre to centre. A mature plant spreads 30–45 cm (12–18 in).
- Does Holy basil need full sun?
- Full sun: at least 6 hours of direct sun a day.
- How much water does Holy basil need?
- Moderate water. Drought tolerance is low and waterlogging tolerance none.
- How cold-hardy is Holy basil?
- It tolerates about 2 °C (36 °F) once established, roughly USDA zone 10. As an annual it is usually planted out after the last frost.
- When does Holy basil flower?
- About 9–13 weeks after planting, for 9–14 weeks.
- Is Holy basil poisonous to cats and dogs?
- For cats it is not known to be toxic; for dogs not known to be toxic; for people not known to be toxic. Related basil is listed as non-toxic by ASPCA; holy basil itself is not separately listed.
- What grows well with Holy basil?
- There is no well-documented companion pairing for Holy basil. Group it with plants that like the same sun (full sun) and water (moderate).
Sources and evidence
Evidence grade C (C: plausible, mixed evidence).
- RHS Plant Finder, Royal Horticultural Society
- University extension gardening guides (general), Various land-grant university extensions
- Plants For A Future database, PFAF
- ASPCA Toxic and Non-Toxic Plant List, ASPCA
Notes and assumptions
- Short-lived tender perennial in the tropics; treated as an annual here. Pet values follow the basil listing.
Reference values for planning, not horticultural, veterinary or medical advice. Varieties, soils and local climates differ: check with a local nursery or extension service.
Related plants
- Basil Ocimum basilicum
- Rosemary Salvia rosmarinus
- Thyme Thymus vulgaris
- Mint Mentha spicata
- English lavender Lavandula angustifolia
- Creeping thyme Thymus serpyllum
- Common sage Salvia officinalis
- Oregano Origanum vulgare