I use to collect the seed of my flowers in the garden, especially annuals and biennials.
I sow annuals in the house in February, and transplant them in the garden when the frost is gone. But, I sow biennials like Dianthus barbatus and Campanula medium immediately after collecting the seeds. Sometimes I sow them directly on the spot but, usually I sow them in the nursery bed and transplant the seedlings in Spring next year. Biennials develop leaves in the first season and flower in the next.
Dianthus barbatus seed
Some seeds need stratification to germinate e.g. Allium. They need a period of cold and they stay in a cold frame during the winter. Sometimes I put them in the refrigerator for 5 -6- weeks before sowing.
I usually sow the seeds in multi - cell trays, and transplant them in individual pots when large enough to handle. Be careful by transplanting; always hold the seedling by the leaves and not the stem. Once broken the stem will never recover.
Some plants, like Acanthus hungaricus quickly run deep roots and they should be transplanted into deep pots.
Acanthus hungaricus seedling
This year I have an extended nursery because I bought lots of seed from Thompson&Morgan . They really have quality seeds and everything is developing nicely.
A part of my nursery
The seed to be sown the next spring should be properly dried and stored in paper bags. Make sure to write the name of the plants on the bag because you will certainly forget which seed is which.
Seed capsules of Aquilegia