Hi, every seed I freshly harvested and has finished warm and cold stratification is ready to be sowed. Michael Dirr, 'The Reference Manual of Woody Plant Propagation' - basically says these seeds are about 1 in 100 approximately of containing embryo's. I've cracked open several but don't see an embryo, only a green fuzzy mass. I've never actually cracked open anything so I can't say I'm positive I know what I'm talking about. I have seen however a seed unfold or crack open on its' own. I assume my seeds are no good. Anybody care to confirm? Thanks very much, Dax
Can't speak for A. griseum specifically. I've found for me, very high embryo % in other Acer species. As well, Acer will frequently germinate for me before the end of cold stratification at 4ºC so I keep them in the fridge until the radicle emerges then pot them up. Simon
All the Acer griseum seed I've ever cut open have been hollow (no embryo, nothing else, either; i.e., no fuzzy green mass). Makes me wonder if yours have some sort of mould inside. I suspect the very low germination rate may be related to poor pollination due to inbreeding among the very limited genebase of the species in cultivation. It would be interesting if someone could get some new sources from China.
Cracking the seed open mentioned because it has been observed that the hard seed coats appear to trap some embryos inside. There may be quite a few viable seeds that don't come up for this reason. Another factor is that isolated single specimens are often what is seen in collections, where there may be one of each kind of specimen tree planted to provide variety (and shade) among a collection of rhododendrons, for instance. One sourwood, one davidia, one paperbark maple...there is little opportunity for cross-pollination among such examples. Where more than one paperbark maple seedling has been planted, as at Bovees nursery in Portland, OR or municipal plantings here in my town, their own seedlings do come up.
Re:RonB - "seedlings coming up" being contrary to todays literature which commonly 'cites' that "Paperbark Maple" is, quote, "not a weedy seed-tree" in a landscape. I figured I was skewered! Thanks the both of you. Dax
Some specimens load up with fruits some years, a small percentage of viable seed could account for those seedlings which do show. I've never seen seedlings carpeting the ground like Norway maple or bigleaf maple.
Dax--I've germinated these for several years with success. The trick for me was collecting from an area with 3 trees very close together, which allowed for the cross pollinating deal. If you crack the seed open now, it will have an embryo, and indeed this time of year the little plant unfolding inside the seed, just like other maples if you're familiar with them. Before going to the trouble of stratifying, I would always crack some open to see that there is a kernel inside. And the best bet for getting this sort of seed is collecting from an area with several trees close together. Then there are the commercial sources like Sheffields that source from China and have already done the checking for viability. Also as you've probably heard these seeds take two years to germinate. Just keep a bag going from each year's harvest, left in a shady spot outdoors subject to all temperature fluctuations, and they will sprout when they are ready. I always do these sort of things in big ziplocs so they are easy to keep moist, very low maintenance until they are ready to poke into individual cells for growing right around this time each year. Once sprouted the griseum is no different in cultural needs to all the other maples, in my experience. Trick is to get that sprout happening!
