|MadSci Network: Botany|
A higher temperature will speed germination but eventually, above a certain limit, it then slows or prevents germination. There is also a minimum temperature below which germination will not occur. So each species has a minimum, optimum, and maximum temperature for germination. The optimal range is 77 to 86 degress F for most species. Alternating day and night temperatures give better germination than constant tempertures. An 18 degree F difference between day and night is optimal. Some seeds require stratification before they will germinate. Stratification is a period of several weeks to several months of cold (around 40 degrees F), moist storage. Reference Hartmann, H.T. and Kester, D.E. 1983. Plant Propagation: Principles and Perspectives. Englewood Cliffs, NJ: Prentice-Hall.
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