The germination of the seeds of weeds and other plants that reseed themselves is noticeably periodic. In some species the grand period of germination closely follows the rise in temperature above freezing and the thawing of the soil in the spring while in other species germination is delayed till late spring or summer, and in the case of winter annuals the seeds germinate mainly in the fall.
Proceedings of the Iowa Academy of Science
©1943 Iowa Academy of Science, Inc.
Martin, John N.
"Germination Studies of the Seeds of Some Common Weeds,"
Proceedings of the Iowa Academy of Science, 50(1), 221-228.
Available at: https://scholarworks.uni.edu/pias/vol50/iss1/16