The monkey puzzle tree is not self fertile and needs to be approximately 30 years old before seeds are produced.
The tree is usually dioecious which means male, pollen bearing cones and female cones waiting to be fertilised grow on separate trees. The male cones are elongated or oval shaped about 4” or 5“ long and during summer release clouds of pollen which hopefully find the female cone which is round, coconut sized and made up of around 200 seeds.
There is no definitive distance how far the wind will send the pollen, but it is thought that trees over a mile apart have successfully produced seed. Clearly though the nearer the trees are to each other, the better the chance of producing fertilised seed. The seeds initially are simply a thin soft, shell but following fertilisation become quite plump and firm as the kernel inside grows into the edible seed which is then capable of producing new trees.
This takes about 18 months, then the following autumn, the female cones fall apart and the individual seeds drop from the tree. They may then be dispersed throughout the countryside by various woodland birds and animals.
Very occasionally the same tree produces both male and female cones, monoecious.
No one has yet been able to identify which sex a monkey puzzle tree is until it has fruited.
A monoecious monkey puzzle tree.
Image by David Gedye, Kent, July2019