When to pollinate JBP cones?

[TimIAm]

I haven't been growing JBP for very long. I have a mature JBP which has put out a lot of male pollen cones and if I lightly bump the tree plenty of pollen goes flying, so I know on the male side it is the right time. I am trying to figure out with the female cones, how large are they supposed to be for pollination? The ones I have on other JBP I'm growing are quite small. Is it possible the trees are not mature enough to produce larger female cones or is now the right time to pollinate when the cones are small?

I've searched and can't find any pictures to indicate what a JBP female cone should look like when it is ready for pollination.

If now is the right time to pollinate, how long until cones are mature for seed collection?

Thanks.

 

[Wires_Guy_wires]

The trees usually synchronize their flowering times within a certain family. That's how they prevent spending all that energy for nothing.
The flowering parts of female pines are pollinated when they're about half a centimeter; still green or yellow and looking fresh. Later on they mature to green, form scales and then turn woody when they ripen. In healthy full sized plants this can take about a year.
In bonsai culture, with small pots and limited growth potential, two or three years is reasonable.

You probably don't have to manually pollinate the female trees, since you have males ejecting pollen by the billions every minute. A gust of wind is all it takes.

Unfertilized cones are usually rejected by the plant, so if they stay put then it's very likely that pollination has occurred. If you want to increase the chances, put the males in a wind-free place that is not bothered by rain. Take some aluminium foil and keep it under one of those pollen cones, shake the pollen out, catch it with the foil, and then brush it onto the female cones every other day. You can mix the pollen with regular baking flour in a 1:50 ratio (1 part pollen, 50 parts flour. no salts or soda added) and freeze it in a closed eppendorf tube, add some dry rice if you want to. When thawing, make sure you have it out of the freezer for half an hour, closed(!!!) before opening the tube. This prevents water droplets from ruining the pollen.
You can freeze-thaw it four to six times before it stops being biologically active.
At 20 degrees C you can store it dry for about 4-5 days.

 

[Shibui]

Trees have been doing this quite successfully for millions of years before we came along. They know what to do and when. I notice that almost all of my pines release pollen almost simultaneously. Almost all done in a week or 10 days. If the male pollen cones are releasing it means the females are also receptive, otherwise it's pointless and the species would have died out. Female cones are definitely receptive when very small but it then takes 18 months for the cone to mature.

It may be necessary to assist with pollination of potted trees. I found that most cones on potted trees had no seed. Typically, the female cones are way up top and male cones lower on each shoot. That's probably an adaptation to reduce self fertilisation hoping that pollen from other trees will float by on the wind from trees higher up the hill or upwind. I carefully pick up a tree with male flowers and bring it close to one with female cones then bump the branches to cause a pollen shower around and over the female cones. It doesn't take much pollen to fertilise a pine cone but a bit of a helping hand may be worth while.