I got my marula seeds from a forum member in South Africa, so know nothing about the Fruit and Spice Park trees, but I am certainly hoping mine eventually flower and fruit! I have had good luck with other trees such as cacao and different annonas.
My previous batch of marula were about 10 ft tall, but I only had three and had no idea if they were male or female, and didn't want them taking up space while I waited to find out, so I cut them down. Once I heard about how to tell the difference between male and female seeds, I started a new batch, keeping them carefully marked from the sprouting stage onward. I plan to graft some male branches onto the female trees when they get bigger (they are 4 ft tall right now) so I don't have to keep so many trees.
On another note, I had been meaning to ask this - has anyone else seen a difference in the growth patterns and vigor of male vs female marula seedlings? I have noticed that my male trees seem to be much taller and more vigorous, whereas my female trees are bushier. Also, when I pruned them to force branching, the males put up multiple leaders, whereas the females only made a single leader.
Cheers,
Carolyn