BBC “botanist?” sources describing why best flower bloom (germination) in Death Valley since 2016.
“The trigger was an unusually wet autumn. Record rainfall of 2.41in (6.1cm) hit Death Valley in the autumn of 2025, soaking seeds and washing off their protective coatings to trigger sprouting, followed by a dramatically wetter winter that provided the steady moisture needed for root development.”
Hmmmm wonder if trigger applicable to rose seeds?
Must be why warm-hot winter rose areas use “frig. cool moist blotter paper towel / media”???
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The noted flowers in Death Valley are actually mostly winter annuals that probably never need conventional (cold, moist) stratification to germinate, so it’s a bit different (I’m also not sure that “washing off their protective coatings” is a physiologically accurate description–there might be some scarification that happens, but probably not a water-driven coat-shedding event), but moisture is generally also considered to be necessary for (cold, moist) stratification to take place. To the extent that ripe rose hip flesh contains chemical germination inhibitors, having plenty of water to rinse that away and/or to aid in its biological breakdown probably does have an important natural role to play in addition to the (cold, moist) stratification process. Hips being eaten and “processed” by animals is probably even better.
Stefan
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Next fall washing, and in a temporary fit of madness entertaining using sealed mesh bag or cheese cloth for seeds, throw in a bit of pearlite or other and putting it in the dishwasher (or unlikely the washing machine). Then -0C. Scratched using vitamix too aggressive. Might entertain crosses but doubt it. Read something similar done before.
Problem is with media a pita to pickout seeds.
Also when did the vitamix experiment a couple of years ago to quickly extract seeds from hip flesh … don’t remember any of the hundreds of seeds germinating from various varieties.
Must add following fill ins about tested method technique.
o all late season hips but not desiccated / frozen
o from tough for me to germinate roses and all OPs (eg The Hunter, Prairie Dawn, M6910, Butterball)
o Speed selected to minimize damage to seeds - higher speeds split seeds.
o screen os garbaged until only seeds and some “hip pulp” remained as screen size opening size reduced.
o Final seed retains under went multiple tap water washings to reduce entrained hip pulp
o seeds damp and paper dapped air dried for short period (< 6 hours for most part)
Normal ice cold stratification used.
Highly irritated when nothing germinated as in “0”. At least normal stratification produced 1 seedling (Prairie Dawn) that still lives.
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