Black salsify is to a large extent biannual. The first year in April the seeds are sown in trays. The plantlets are transplanted into a field in May for developing roots. Roots can be left in the field during winter or harvested in November and planted again in March of the second year. The second year the plants will produce seed.
About 50 plants per accession are used for regeneration with a minimum of 20 plants and a maximum of 100 plants.
- Black salsify is a cross-fertilizing crop. Therefor the material must be isolated in multi-crop isolation plots, with a minimum distance from each other of at least 50 meters.
- A second possibility for regenerating is using gauze isolation cages or tunnels where the plants are kept in pots.
- The plants are pollinated by insects available on the spot.
- As soon as 50% of the plants are flowering, bumble bees must be brought into the cages.
The crop is monitored closely. When a disease or pest is identified that might jeopardize proper multiplication of the seeds, a treatment must applied.
- Just before or directly after the seedheads (capitula) are opened, they must be picked and stored in gauze bags. Ripe seeds shed very soon and will be distributed by wind. This means that it is necessary to harvest often over a longer period.
- The harvested seedheads are stored in a dry air-conditioned room.
- Sieves and blowing with air can be used to clean the seeds further.
- Cleaned seed samples must be dried well and stored under circumstances with low temperature and relative humidity.