Some indigenous species need seed pre-treatments to break their dormancy. The various methods of seed pre-treatment methods for stratification, hot water, scarification and dry heat are described below The Seedling Database will give seed pre-treatment for individual species.
Cold/Refrigeration - stratification
Some species require one to several weeks of refrigeration (stratification). Place seeds that need a cold period in a sealed container with moist vermiculite. Refrigerate for 2-6 weeks depending on requirements.
Hot water treatment
Put the seed into a nonporous container, cover with boiled water. Soak for 18 to 24 hours. Sow the seeds which have swollen. Treat again those that did not swell. Seeds that float or do not swell should be discarded as they are infertile.
Roughen the seed coat using fine sheets of sandpaper or nick the seed with a thin sharp knife. This allows water to penetrate the hard seed coat. Pay attention not to damage small fleshy appendage called the aril, which develops into the root.
Spread the seeds in a thin layer on an oven tray. Place in the oven at temperature indicated for that species Remove as soon as the seeds have popped open. Do not burn.
Seedling Database - select a seedling species to find information about the:
- Seed description
- Seed image
- Germination notes
- Sowing notes
- Image of seedlings at different stage of growth
- Link to image of the mature tree/shrub/grass