Storage moisture content and temperature
Store moist @ 4°C
12 (8-16) weeks cold (c. 4°C)
Efficacy of pretreatment / remarks
Generally effective although pretreatment durations, and numbers of repeat cycles may vary significantly between seedlots
Approximate date to initiate artificial pre-treatment (for 1 March sowing) 6 December
Recalcitrant - seeds that cannot be dried or frozen and are therefore short-lived.
Figures in brackets indicate that different seedlots often require different pretreatment durations. There are three potential courses of action:
- Adhere to the pretreatment duration in bold, with the knowledge that the maximum potential germination of the seedlot may be sacrificed for the sake of simplicity.
- Inspect the pretreating seed regularly. Sow when c. 10% of seed is chitted, with the hope that this is indicative that the remaining seeds are now close to germination.
- Inspect the pretreating seed regularly. At suitable intervals, remove chitted seeds (by hand, flotation, and/or sieving). Sow chitted seeds and return balance to pretreatment until no more seeds germinate.
Raising Trees and Shrubs from Seed (PDF-648K)
Forestry Commission Practice Guide 18.