Stratification of Eucalyptus Seed

Eucalyptus Study Group

Viable mature seeds of most Eucalyptus species germinate under favourable conditions without preconditioning. However, a few species, particularly from alpine areas, require cold moist pretreatment to break dormancy. Cold moist stratification can generally overcome dormancy in seed of all eucalypts that grow naturally in the alpine forests of Australia.

The stratification process is very simple. Firstly, sow the seeds onto a moist substrate in the germination container (tray, punnet, or whatever you normally use). That is, plant the seeds exactly as you do normally. Then cover the germination container with a lid or plastic sheet to minimise drying, and place in a refrigerated environment at 1 to 4^oC. Check occasionally to see that the substrate remains moist.

The species which are generally considered to require stratification, and the recommended duration of treatment are listed below:

• Three weeks of stratification is essential to break the dormancy of seeds of E.perriniana (spinning gum) and will also ensure more rapid and even germination of seed of E.amygdalina, E.dives, E.nitens, E.pauciflora ssp. pauciflora, E.regnans, E.stellulata.
• Four weeks is essential for E.glaucescens and E.pauciflora ssp.niphophila.
• Six weeks is required by E.kybeanensis, E.mitchellana and E.pauciflora ssp. debeuzevillei.
• E.delegatensis requires 6-10 weeks, depending on seed source.

After the stratification treatment is over, simply remove the germination container(s) from the refrigerator and leave them at room temperature. Germination will commence within 3-5 days.

From the newsletter of ASGAP's Eucalyptus Study Group, July 1986.

Australian Plants online - 2007
Association of Societies for Growing Australian Plants