Natural (outdoor) pretreatment/germination with medium for deeply or shallowly dormant tree seeds.

1. Determine prescribed cold, or warm plus cold pretreatment durations for individual species and calculate likely start date for natural, outdoor pretreatment to begin in your district.
2. Prepare a moisture retaining medium by mixing one volume of an organic material (such as peat, decomposed leaf litter, or peat alternative) with one volume of a coarse particle material (such as sand, grit, perlite or vermiculite).
3. Place moisture retaining medium into a seed tray. Sow seeds. Place seed tray in loosely tied poly bag (to retard drying, but allow gaseous exchange).
   
4. Transfer seed tray outdoors, either against a sheltered, north-facing wall; in a permanently shady position or buried in the ground to receive exposure to seasonal temperature fluctuations, whilst avoiding wide daily temperature changes. Ensure that it is protected from rodents and other seed predators.
5. Inspect seeds regularly (preferably weekly to fortnightly) for the following:
   • Re–moisten the stratification mix if necessary in dry weather.
   • Remove decaying seeds to prevent the spread of fungal infections.
6. Either:
   • Remove and sow germinating seeds at each inspection
   • Apply the prescribed pretreatment duration and on completion transfer the seed tray to warmer conditions; or
   • Wait until approximately 10% of seeds have begun to split, chit or germinate and transfer the seed tray to warmer conditions.