Oregano (Origanum vulgare) is a hardy, aromatic perennial herb belonging to the mint family. It is a staple in Mediterranean and Italian cuisine, lending a warm, pungent flavor to sauces, meats, and vegetables. Growing this popular herb from seed is a straightforward process, provided specific requirements for its tiny seeds are met.
Timing and Preparation for Starting Seeds
The process for starting oregano seeds should begin indoors six to ten weeks before the last spring frost. This allows the slow-growing seedlings enough time to develop into sturdy plants ready for transplanting. Alternatively, seeds can be sown directly into the garden bed once the weather has warmed and the danger of frost has passed.
For indoor starting, select clean containers or seed trays with excellent drainage. Fill these with a sterile, fine-textured seed-starting mix. Before scattering the minute seeds, lightly pre-moisten the growing medium until it is evenly damp. This prevents the seeds from being washed away during the first watering.
The Critical Need for Surface Sowing
The small size of oregano seeds dictates a shallow planting method. Unlike many garden seeds that must be buried, oregano seeds require light to trigger germination, a biological trait known as being photoblastic. Planting them too deeply prevents the necessary light from reaching the seed.
The seeds should be surface-sown by gently sprinkling them across the prepared, moist soil surface. Avoid covering them, or use only a dusting of fine vermiculite or soil, no more than 1/8 of an inch deep. After sowing, lightly press the seeds into the medium to ensure good contact without submerging them.
Essential Care for Seedling Emergence
After the seeds are sown, maintaining consistent moisture is important, as the tiny seeds can dry out quickly. Instead of using a watering can, which can displace the surface-sown seeds, use a gentle misting bottle or employ bottom watering. Bottom watering involves placing the tray in a shallow basin of water, allowing the medium to soak up moisture from below.
Successful germination depends on temperature, with an ideal range between 65°F and 70°F. To prevent seedlings from becoming thin and weak (legginess), they need intense light exposure immediately upon sprouting. Supplemental lighting from a grow light, positioned closely above the seedlings for about 16 hours daily, provides the necessary consistent intensity.
Once the seedlings have emerged, provide good air circulation to reduce the risk of damping off, a fungal disease that causes young stems to collapse. Thinning the seedlings early prevents overcrowding, improves airflow, and helps the remaining plants establish stronger root systems.