What are the key components of a good Seed Raising Mix?
- Particle size – a good blend of small (sand), medium (pumice) and large (granulated bark) particles to keep mix light & free draining.
- Starter fertilizer – a mild fertilizer to last six weeks in the tray.
- Gypsum – for strong root development.
- Saturaid – a wetting agent for even hydration.
- Either Fungicide – to protect vulnerable seeds from disease like damping off or
- Beneficial Fungi called Trichoderma.
NB: Fungicides kill all fungi whereas Trichoderma encourage healthy soil conditions and occupy the space that harmful fungi would otherwise take up. Harmful soil fungi include: Phythium, Sclerotinia, Fusarium and Rhizoctonia.
Buy fresh mix each season! Just like anything else it can become stale, begin to break down, dry out and the value of the short term fertilizer is reduced significantly.
Seed Raising Mix versus Tub or Potting Mixes?
- Seed Raising Mix has a fertiliser designed to last 6 weeks.
- Other mixes have fertiliser to last 3-6 months – they’re usually quite acidic and will burn tender young seedlings.
- Work in a well ventilated space to avoid inhaling the dust.
- Fill tray with 3cm of Seed Raising mix – any higher and it’s a waste of mix.
- Gently pat the mix down and water lightly so the mix is moist.
- Scatter the seed evenly in the tray and cover lightly.
- Rule of thumb? No more than twice the diameter of the seed.
- Tamp the mix down again and water lightly. Another option is to gently soak then drain the whole tray.
- Cover the tray with glass, perspex or glad wrap to maintain temperature and moisture levels.
- When germination begins remove cover and move to a sheltered area with good natural sunlight.
- Transplant seedlings when they are large enough to be handled.
- Continue using Seed Raising Mix at the transplant or “pricking out” stage (moving individual seedlings from the tray to separate pots).