If I let a sweet potato vine to climb a trellis, will it produce the tubers?
I thought that this vine needs to creep on the ground and it will produce tubers along the vine... Please, correct me if I am wrong.
Sweet potatoes will produce tubers from where you inserted the slip in the ground. As the vines grow along the ground they will take root. If you have a very long growing season, tropical or close to that, it might have time to start producing more tubers from those areas where it has rooted. In shorter growing seasons there won't be time. You might even find that it reduces the crop you harvest because the plant is dividing it's energy instead of focusing on the first set of tubers. Particularly in a short season climate, you won't hurt the plant at all if you train it up a trellis.
Here I use the sweet potato vines as it's own grown cover to keep grass out of it's bed. I think it must be forming small tubers that are just large enough to survive the winter. I think I have around 200 viable growing days for sweet potatoes. The full growing season is closer to 300 days but I don't like to plant them until it's starting to get truly hot, and they're very sensitive to cold on the other end of the growing season.
We trellis one sweet potato vine every year because that is the one we pluck leaves from for greens. The others we let grow as they will and bury a node about every three nodes.
Once that buried node puts out roots, I cut it free of the parent, this sets the new plant into tuber mode so we get more sweet potatoes at harvest time (for us that is November).
Through experimentation I found that this method works far better than leaving a vine whole and just covering nodes with soil.
Once you cut the newly rooting plant from the parent vine, the parent vine doesn't give up tuber making energy to the newly rooted part you snipped free. You have created two slips from one using this method.
I have a buddy that lives in Australia and he grows sweets all year long. By using the root a vine node and cut it free, he got normal tuber growth from all his vines two years ago.
Prior to that he would just bury a node here and there but he would only get a couple of good sized sweets per buried node. Now he gets 5-6 extra large sweets per buried node using this method.
He and I did the experiment at the same time of year and we both got near equal results so we have switched to the new method of cutting the new rooted vine free from the parent.
We grow our initial plants in tubs because of a vole problem. As the vines grow I leave about two feet of parent vine before I bury any nodes for new plant generation.
In last years season I managed to create 5 new plants per vine, and we still have some sweet potatoes to eat.