Common Name Oregano (includes Common, Golden, Golden Variegated, Greek, Hot and Spicy, Italian, Supreme)
Genus  Origanum
Species Various (e.g., Origanum vulgare for Common and Greek Oregano, Origanum vulgare ‘Aureum’ for Golden Oregano)
Family Lamiaceae
Life Cycle  Perennial in USDA Zones 4-9; may be grown as an annual in colder climates. Common oregano will self-seed freely. 
Tray Size  50 (half tray)
Plug Care Plant plugs soon after arrival - do not allow to become rootbound. Maintain consistent moisture but avoid over or under watering while still in the plug trays. Harden off before planting to avoid sunscald. 
Netting / Staking Not required. Oregano has a naturally compact and bushy growth habit. Even the taller growing cultivars should support themselves, unless grown in an area with high wind.
Temperature Range Thrives in temperatures of 65-80°F. Tolerant of heat and drought once established; protect young plants from frost.
Spacing Space plants 12-18 inches apart (depending on variety) to allow for proper air circulation and growth. You can attempt more intensive spacing but avoid overhead watering and monitor foliage for disease or fungal issues - especially on lower branches. 
Soil Preference Prefers well-draining, sandy or loamy soil with a pH of 6.0-8.0. Tolerates poor soils but thrives in moderately fertile conditions. Although it is drought tolerant once established, regular irrigation will provide the best quality foliage. 
Day Length Day-neutral; grows best in full sun but tolerates light shade in hotter climates.
Pinching Pinch growing tips regularly to encourage branching and denser foliage. Remove flower buds to prolong the harvest season. 
When to Plant Plant in the spring after the danger of frost has passed and the soil has warmed. Can be planted from early spring through to late summer for fall establishment.
Harvesting Harvest stems when they have reached the desired length. For cut-flower use, let the plant grow un-pinched until the stems are either flowering or close to it, and then harvest the entire plant back to a few inches from the ground. The plant will send out new growth and provide another flush of cut material.
Post Harvest Care Place stems in water immediately after cutting. Oregano has a vase life of 5-7 days. Use floral preservatives to extend freshness; good candidate for drying (for culinary uses). 
Diseases / Insects Generally pest-resistant but may be affected by spider mites, aphids, or fungal issues in humid conditions. Ensure good air circulation and avoid overhead watering.
Bailey's Notes Oregano is rather uncommon in the cut flower world, but is suitable for adding texture and a subtle fragrance to mixed bouquets. Not all varieties in the catalog are tall - some are compact or mounding, so be sure to research each specific variety prior to ordering. With proper care, oregano can be a long-lasting and productive addition to your cut flower field.
Resources

University of Maryland Extension: Oregano Growing Guide

North Carolina State Extension: Origanum spp. Profile

Missouri Botanical Garden Plant Finder: Origanum vulgare

Royal Horticultural Society (RHS): Oregano Care Tips

University of California IPM: Oregano Pest Management