Oregano
Origanum vulgare
Also known as: Wild marjoram, Greek oregano, Italian oregano, Origano
Quick facts
- Category
- herbs woody
- Difficulty
- intermediate
- Days to harvest
- 80 to 120 days
- Harvest type
- continuous production over weeks or months
- Spacing
- 30 cm between plants
Environment
- Temperature
- 13–28°C
- pH
- 6 to 7.5
- EC (hydroponic)
- 1.5 to 2 mS/cm
- Daily light
- 18 to 25 mol/m²/day
Climate and zones
- USDA zones
- 4 to 10 (winter low around -34°C or warmer)
- Frost tolerance
- frost hardy (handles regular frost)
- Season
- warm (summer crops, frost-sensitive)
Viable growing environments:
- outdoor year-round (in zone)
- outdoor in growing season (annual)
- unheated greenhouse / hoop house
- heated greenhouse
- indoor (heated home)
- indoor hydroponics under grow lights
USDA zone bounds reflect outdoor year-round survival. Anywhere outside the bounded zone range, this crop still grows as an annual in the warm months (outdoor_seasonal), under cover (greenhouse), or indoors under lights.
Growing systems
Oregano works in:
- drip / Dutch buckets
- media bed (ebb and flow)
- wicking bed
- soil bed
Growing media
The substrate the roots sit in. Choice depends on the system (clay pebbles don't fit NFT channels; rockwool isn't used in media beds) and the crop (oregano works in the media listed below).
| Medium | pH effect | Water retention | Bacterial surface |
|---|---|---|---|
| Expanded clay pebbles (LECA) | neutral / inert | low | high |
| Coco coir (Coconut coir) | slightly acidic | high | moderate |
| Soil-based mix (Potting soil) | varies by source | high | high |
Bacterial surface area matters for aquaponics: clay pebbles, lava rock, and pumice double as biofilter substrate. Low-surface media (rockwool, perlite, pea gravel) work in hydroponics but need a separate biofilter in aquaponics.
Nutrient demand by stage
NPK ratios are relative weights at each growth stage; the nutrient mix calculator scales them to absolute grams or ml. EC targets shift through the plant's life: seedlings need a much lighter solution than fruiting adults.
| Stage | N | P | K | EC target (mS/cm) |
|---|---|---|---|---|
| seedling | 1 | 1 | 1 | 0.8 |
| vegetative | 2 | 1 | 2 | 1.8 |
Aquaponics suitability
Not recommended for pure aquaponics. Fish waste alone doesn't provide enough of the nutrients this crop demands (typically potassium, calcium, or boron). It can be grown in a hybrid system where the reservoir is supplemented with hydroponic-style nutrients, but expect to dose actively.
Care notes
An easy, long-lived perennial herb for hydroponic systems. EC 1.0-1.8 mS/cm. pH 6.0-8.0 (tolerates alkaline conditions). Temperature: 15–30°C (Mediterranean; cold-hardy to zone 4). Full sun (DLI 16-25 mol/m2/day; the essential oil concentration is highest with strong light). Well-drained media preferred. Any hydroponic system works, though container growing with excellent drainage suits the Mediterranean habit. From seed or cutting to first harvest: 6-8 weeks. Harvest by cutting stem tips; the plant branches freely when pinched. The flavor is strongest just before flowering. For drying (the most common preservation method): cut whole stems, hang in bundles, and strip leaves once dry, or dehydrate at 35–40°C. Dried oregano in a sealed jar retains good flavor for 12-18 months. Greek oregano (specify when buying seed or plants) is the type for pizza, pasta sauce, and Greek cooking. Propagation by stem cuttings, division, or seed. A single well-maintained oregano plant provides enough dried herb for a household indefinitely.
Verified against: rhs-uk. Last reviewed 2026-05-15.