CERCIS canadensis

This magnificent tree is famous for its lavender bells during summer and the carpet of fallen flowers around it. Foliage is finely divided and also extremely attractive.

The wood is purple with dark venation.

Native to Canada

Prefers a deep well-drained soil in an open sunny position, frost resistant but drought tender.

Although seed can be sown most of the year in Australia seed is generally best sown in spring or autumn, avoid the coldest and hottest months of the year. The optimum germination temperature for germination is around 18-22°C

For best results both scarification and stratification are recommended.

Cercis seeds have a hard outer coating which is impervious to water and generally germination will normally not occur unless the seed is scarified by abrading or pre-treated with boiling water first. They also benefit from a period of cold stratification.

1. Place the seed in a container and pour in just boiled water and allow to soak overnight.
2. Sow seed in container to depth of seed width.
3. Ensure the mix is moist but not water logged.
4. Place the container in plastic bag.
5. Place the bagged container in the refrigerator for 42-56 days.
6. Germination generally occurs in 21-28 days when moved to warmer temperatures after the period of cold treatment.

General note: Seeds of many plants are dormant and require specific conditions or pre-treatment for germination.
Do not be too hasty to discard seed that does not germinate, seeds will often lay dormant until the conditions are similar to their natural requirements for germination to occur. Containers put to one side will often surprise long after they were discarded.

Wikipedia

Missouri Botanical Garden