Hello, thanks for replying!
That's some bad news, sorry to hear that. But good to hear that you're keeping up with your hobby and started to grow again.
Yes I know durian are not easy ones, it's more of an experiment for me to see what is possible in my climate, with and without greenhouse conditions. Also grafted plants don't grow as vigorous and tall as non grafted ones. Makes it easier for me to keep it under control in the longterm. If I manage to keep them alive and let's say it will flower someday, it would be a shame if it's self incompatible.
So far, the tap roots are digging deep into the soil, there are no signs of leafs yet. If they make it through winter, I will try to get some scions and graft them next year at the end of spring.
But til then I'm trying to find a source for scions. If it's all working as planned, I may will have a grafted plant to spare next year if you're interested.
The D. kinabaluensis seems promising, but seeds aren't that easy to obtain either, right?
Indeed, it was hard and must've been hundred times harder for my friend, who lost thousands of plants and incredibly rare species, many of which were already fruiting. He had one of the largest of collections. He told me this year he will never get back to it, which I understand.
From durio species, I had oxleyanus, graveolens, kutejensis, dulcis, kinabaluensis and zibethinus. As far as I remember, the one that grew best was oxleyanus, at least in the beginning. I was trying to get other species as well, especially testudinarum, but that seemed nearly impossible.
D. kinabaluensis is fairly rare and quite hard to get, but definitely not impossible. I bought it on two separate occasions from two different sources, always with a success.
I've never heard of a flowering durian in the European region, but maybe such a plant is somewhere out there? And with the climate changes and temperatures rising, who knows what will be possible in the upcoming years? I've contacted several botanical gardens if they happen to have a mature plant that is already flowering, but I never found one.
I was thinking that if one would want to successfully grow a durian tree and make it fruit, you would need a huge, top-of-the-line greenhouse and pump millions into the project to maintain the optimal conditions throughout the year. Heating, artificial light, keeping humidity levels, and maintaining optimal quality of the soil (ideally they would need to be in the ground). But sadly, no one with spare millions has that kind of ambition I guess.
The reason I gave up on durians is exactly the above... I realized that I want to grow plants that I can later harvest fruit from and with durian, it just seems more like a dream. Not that I want to discourage you of course. It's a great challenge that can be exciting and motivational, pushing the boundaries of what's possible. That was my motivation all those years back - that, plus my love for the fruit, which is just out of this world.
In any case, my experience is that the seeds are sprouting perfectly, they grow quite fast and strong in the first couple of months and then they usually started to slow down and also somewhat deteriorate. Though I've seen a beautiful durian tree seedling from France I believe, which was growing in an apartment close to a heating pipe (which is usually bad for plants as it dries out the air) and it was looking incredible. I think it was about 2 years old.
The durians that my friend had were growing in a tropical greenhouse and they were growing much better, but still not as well as Artocarpus for instance. They were quite slow in their growth and the leaves didn't look entirely healthy. I think it's really a lottery when it comes to growing these as they are extremely sensitive.
But I think wild durians might be an interesting experiment. Either the above mentioned D. oxleyanus or D. kinabaluensis. You could also use one of these as a rootstock to graft zibethinus varietes on it. Might be worth the shot as well. I know we wanted to try graft durian onto Cullenia excelsa, which is related to durians and might be more vigorous and resistant. I don't know if that would work though.
I would definitely be interested in a grafted plant, thank you for the offer! I always wanted to acquire one back then but it seemed impossible... All the leads that I had (to grafted plants and scions) always led to a dead-end, unfortunately. But it's definitely not impossible!