Jeffersonia diphylla

Germination Tips

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Sow immediately. The viability of these seeds is short or the species propagates best with fresh seed. Stored seed might be coaxed into germination with temperature cycling and patience.

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This species needs special care as described.

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Sow @ 20°C for 6 weeks, then place @ 4°C for 6 weeks, then slowly raise temperature to 10°C for 6 weeks. If there is no germination, repeat the cycle. This mimics fall sowing outdoors for spring germination.
Special Care: 
Jeffersonia seeds are hydrophilic and the embryo will die if seed dries out. Sowing the seeds before any drying occurs is the best approach. However, if they are to undergo a period of storage, they are first allowed to dry a bit and then are sealed in a plastic bag in slightly moist vermiculite. Expect germination while in cold cycle. Research by Jeffery and Carol Baskin demonstrated "Freshly-matured seeds of ... Jeffersonia diphylla .....have underdeveloped (ca. 0.6 mm in length) embryos and exhibit deep, simple morphophysiological dormancy (MPD). For rapid growth of the embryos at October (20°/10° C) and November (15°/6° C) temperatures in October and November, seeds must first be exposed to high (30°/15°C) summer temperatures. If embryo growth is not completed in autumn, it continues during winter. However, even after 10-12 weeks at summer temperatures, embryos grew very little at 5°C, unless growth already had begun at autumn temperatures. After embryo growth has been completed, or after it has been initiated, seeds require cold stratification (5°C) to overcome dormancy. Embryos must attain a minimum length of about 1 mm before seed dormancy can be broken by cold stratification. Gibberellic acid increased the rate of embryo growth in seeds kept at 20°C, but only 1-9% of them germinated. Thus, GA substitutes for warm but not cold stratification. High summer temperatures, as well as the traditionally-used autumn and winter temperatures, should be used in germinating seeds with deep, simple MPD."
Most of the seeds in our Germination Guide have been offered from time to time in our annual Seed Exchange (Seedex).