Artichokes can be propagated in 3 ways:
- By Seed
- By Offshoots - Side shoots
- By Root crown division (underground shoots with apical and lateral buds, called "ovoli")
Seed propagation is a cost-effective method. It can also be used in laboratories for breeding purposes. Worldwide, many farmers (e.g., in Texas) choose this propagation technique. For seed propagation, growers sow the seeds in seed beds at a seed depth of 0.4 inches (1 cm) inside a protected environment under controlled temperature and moisture conditions. The optimum temperatures for artichoke seeds sprouting are 21-26℃ (70-79°F). For a hectare, they need approximately 1,200-1,500 grams of seed (1-1.3 lb/acre). As a substrate, they prefer turf. They keep the substrate constantly moist until the seeds sprout. Under optimum conditions, seeds will sprout approximately after 8-12 days. If the plants have been sown in pots, they require 2-2,5 months to reach a transplantable size. The transplanting in the field can occur in mid-fall (mid-October for the North hemisphere). Some promising and good-yielding hybrids have also entered the market in the past 30 years but are still not widely used. The two main reasons are the high cost that many farmers cannot afford and the delayed head formation. On the other hand, researchers found that specific cultivars exhibit an extended harvesting period when propagated by seeds, resulting in a higher yield and head number produced per plant.
Offshoots or side shoots are the most commonly used artichoke propagation method. Artichokes have a natural tendency to constantly develop offshoots from the germination of buds of the rhizome. These offshoots can be gently removed when they reach 25-40 cm (9.9-16 inches) in length, having 4-6 leaves, and directly transplanted into their final positions. They subsequently are covered up to 10-15 cm (4-6 inches) with soil. The best period to collect artichoke offshoots is early to mid-fall (September - October for the North hemisphere) in warm areas and March in cooler regions. However, vegetative propagation has the great disadvantage of a high risk of disease transmission.
Root crown division is another commonly used method for artichoke asexual (vegetative) propagation. The underground part of an artichoke consists of 3 root crowns. Producers can gently remove the root crowns of a mature mother artichoke during the dormancy period. Afterward, they divide the root crown into smaller parts provided each part has at least two buds. Finally, they bury the crowns under moist sand until they are ready for transplanting. Like in the propagation with side shoots, the grower should be careful when selecting and cutting the planting stock to avoid transmitting any diseases. You shall choose root crowns from healthy plants only.
References
https://core.ac.uk/download/pdf/95164724.pdf
https://agrilifeextension.tamu.edu/library/gardening/artichokes/
Calabrese, N.; Carito, A. Yield evaluation of new seed propagated artichoke cultivars. Acta Hortic. 2013, 983, 393–397
García, S. M., Cointry, E., López Anido, F., Firpo, I. T., Cravero, V. P., & Rotondo, R. (2009, June). Evaluation of two propagation systems in globe artichoke. In VII International Symposium on Artichoke, Cardoon and Their Wild Relatives 942 (pp. 147-152).
How to Grow Artichokes at Home
How to Grow Artichokes for Profit – Professional Artichoke Farming
Artichoke Propagation
Climate and Soil Requirements for Artichoke Farming
Soil Preparation and Planting in Artichoke Farming
Artichoke Water Requirements and Irrigation Systems
Artichoke Fertilization Requirements
Artichoke Farming: Harvest, Yield, Storage, and Post-harvest handling