First I thought maybe they are hybrids and sterile but then I was reading that there are male and female. Males have the yellow flowers. If this is true, looks like they all have yellow flowers. Does yours on the right also have yellow flowers?
Mine also have yellow flowers and I even tried unsuccessfully hand-pollinate them with pollen collected of plants in WAP.
Where did you find the info that there are male and female plants/flowers of A. dichotoma?
Male trees are recognisable by their bright yellow flowers, about 3 cm long, that grow close to the leaves in winter. Female trees have light red cones, dotted with green. Wind, and desert whirlwinds known as ‘dust devils’, are mainly responsible for pollination. It is believed that insects, attracted by the sweet nectar of the flower, are also responsible for pollination, but this has not yet been established as a fact.
thanks for that info. Unfortunately this is just wrong. Aloe dichotoma is not dioecious!
I finally checked with the experts in South Africa and received this answer:
"Your question concerning Aloe dichotoma.
Aloe dichotoma has male and female parts on the same tree, thus males and females are not separate... You should continuously pollinate at morning midday, afternoon and until the flower are spent. With us they flower early winter and winter, thus when it is relatively cool
I am sure you would get some results- keep on trying.
Ernst van Jaarsveld"
Still not an explanation why pollination here does not work.
I just emailed South Africa today to get info on a protea! LOL I am hoping I get an answer as they have helped me in the past.
Sounds like you need to pollinate one flower many, many times to get it to take. Have you done that? How long does one flower last? A couple of days? So then it is many times every day till the flower is done. I wonder if there is a certain time of day that is better when the stigma is more receptive to the pollen.
When I do my variegated clivia I try to hit them in the morning and the afternoon to get more berries. I should really do a study to see what time is better. The other variable is the age of the flower and the age of the pollen. I know with clivia supposedly if the pollen gets wet it is no longer good. So I try to collect it the first day it looks viable for nights can be damp.