Onions may be grown from seeds or from partially grown bulbs called "sets" or starter bulbs. Because onion seeds are short-lived, fresh seeds germinate more effectively when sown in shallow rows, or "drills," with each drill 12" to 18" apart. [57] [59] In suitable climates, certain cultivars can be sown in late summer and autumn to overwinter in the ground and produce early crops the following year. [14] Zohary, Daniel; Hopf, Maria (2000). Domestication of plants in the Old World (Thirded.). Oxford: Oxford University Press. p.198. ISBN 978-0-19-850357-6.

Imperial Library (last working) link: http://xfmro77i3lixucja.onion or http://kx5thpx2olielkihfyo4jgjqfb7zx7wxr3sd4xzt26ochei4m6f7tayd.onion 12. Archive.today Abdel-Maksouda, Gomaa; El-Aminb, Abdel-Rahman (2011). "A review on the materials used during the mummification process in ancient Egypt" (PDF). Mediterranean Archaeology and Archaeometry. 11 (2): 129–150. Archived (PDF) from the original on 8 March 2014 . Retrieved 13 September 2013.Eye irritation can be avoided by cutting onions under running water or submerged in a basin of water. [39] Leaving the root end intact also reduces irritation as the onion base has a higher concentration of sulphur compounds than the rest of the bulb. [40] Oulton, Randal (9 September 2005). "Bermuda Onions". cooksinfo.com. Archived from the original on 11 February 2021 . Retrieved 25 November 2017. Jauron, Richard (27 July 2009). "Harvesting and storing onions". Iowa State University Extension. Archived from the original on 18 May 2013 . Retrieved 28 March 2013. a b c d Cumo, CE (2015). Onion. In: Foods that Changed History: How Foods Shaped Civilization from the Ancient World to the Present. ABC-CLIO LLC (American Bibliographic Center, CLIO Press). pp.248–50. ISBN 9781440835377. Archived from the original on 4 February 2021 . Retrieved 30 June 2020.

Salgado, B.S.; Monteiro, L.N.; Rocha, N.S. (2011). " Allium species poisoning in dogs and cats". Journal of Venomous Animals and Toxins Including Tropical Diseases. 17 (1): 4–11. doi: 10.1590/S1678-91992011000100002. ISSN 1678-9199. USDA, NRCS (n.d.). " Allium cepa". The PLANTS Database (plants.usda.gov). Greensboro, North Carolina: National Plant Data Team . Retrieved 31 March 2013. Onions have particularly large cells that are readily observed under low magnification. Forming a single layer of cells, the bulb epidermis is easy to separate for educational, experimental, and breeding purposes. [31] [32] Onions are therefore commonly used in science education to teach the use of a microscope for observing cell structure. [33] DyeSuslov, D; Verbelen, J. P.; Vissenberg, K (2009). "Onion epidermis as a new model to study the control of growth anisotropy in higher plants". Journal of Experimental Botany. 60 (14): 4175–87. doi: 10.1093/jxb/erp251. PMID 19684107. Allium × proliferum". Germplasm Resources Information Network. Agricultural Research Service, United States Department of Agriculture . Retrieved 21 February 2011. Onion Eelworm ( Ditylenchus dipsaci)". GardenAction. 2011. Archived from the original on 3 February 2013 . Retrieved 29 March 2013. a b c d e f g h i j Fritsch, Reinhard M.; Friesen, Nikolai (2002). "Chapter 1: Evolution, Domestication, and Taxonomy". In Rabinowitch, Haim D.; Currah, Lesley (eds.). Allium Crop Science: Recent Advances. Wallingford, UK: CABI Publishing. doi: 10.1079/9780851995106.0005. ISBN 0-85199-510-1. OCLC 228168061. S2CID 189956991.