Prumnopitys Species, Andean Yew-Pine, Cordillera Grape, Plum-Fruited Yew

In April 2014, I got 4 of these plants from a domestic source. We are in a USDA Zone 7b, and head a severely cold winter (to -5 degrees ...Read MoreF), but all four seedlings made it through the winter.

I have learned that the seedlings are all male, from cuttings. So I'm looking for some female seedlings, or cuttings, from United States sources only.

Does anyone in the United States know of any Prumnopitys Andina trees that are producing the 'plum' type fruit? If so, please D-mail me. I am very interested in this tree, as I have a small collection of Torreya Taxifolia Plum Yews that are producing fruit annually, and I would like to do the same with Prumnopitys Andina.

The following is from http://www.chileflora.com were I purchased my...Read More seeds:

The seeds need cold stratification and should be planted as soon as possible(Because these seeds can not be stored for long times (they are recalcitrant)). Recommended stratification time - 6 months. There is literature mention that the seeds germinate after 20 days to three years. Things which are known to speed up somewhat the process: keep the seeds with rotting fruits (any kind would do, what is needed is the ethylene generated during the rotting process) during the stratification. Another technique is to split the outer shell of the seeds after stratification with a vice. Very delicate job, because the seeds swell up, and it is very easy to damage the embryon. I have not tried it this way.
Now, the realistic way to germinate the seeds of Prumnopitys andina is to dump them in a somewhat acid soil (maybe a box or something like that) and keep at all times humid for a long time in a cool and cold place. It is not a good idea to sow them in autmn if your area has prolongued freezing temperatures, in that case you might store the box inside the house in cool place, and then take it out in spring. Daily temperature fluctuation might increase the germination (no hard data available).