When to start Thunbergia seeds in the greenhouse
I wait all summer for my Spanish Eyes Thunbergia vine to grow and flower. It is worth it. But let me start from the beginning. That would be in the greenhouse in late February or early March.
These seeds look a lot like little brown peas. They are easy to keep track of and plant just the right number of, unlike so many teeny flower seeds. The only thing is they tend to take quite a while to germinate. The seed packet says 10-15 days.
They also have a somewhat erratic rate of germination. The seeds are on the expensive side, so I tend to only plant 1 – 2 per pot.
Seedling care is easy
To make up for the delayed sprout time, the seedlings are relatively large and robust from the very first. They are easy to keep alive. They grow quickly once the real warmth of summer gets going, and they transplant easily. Make sure to mark them well, because the young, non-flowering vines can look a lot like bind weed.
If in a moderately moist and warm environment, they can grow to cover fences. Here in my yard in southwest Idaho, they are still vigorous, but they only cover a small to medium sized trellis. I have found that an eastern exposure gets me the best vines.
Understanding their natural habitat
I have seen vines of Thunbergia, also known as Black Eyed Susan vines, in Africa, Oregon, and Hawaii. In those places the vines are covered with flowers. Here in my yard, it is more like like a game of peek-a-boo for the first blooms.
The plants begin to flower in July, but not profusely. Into August, there are more blooms, but since the plants don’t do as well in the direct, dry heat, I plant them where they get afternoon shade. In these conditions, the vine is happy, but the blooms more like polka dots.
There are different varieties of Thunbergia
I particularly enjoy the variations of golden yellow in the Spanish Eyes variety. It is fun to get close to the vine and see how many I can locate, then notice the uniqueness of each flower. I have grown my vines on both flat and conical trellises. I think they look best on the conical ones, where they reach to the top and then reach tentatively out into the air before latching onto the trellis again.
Saving Thunbergia seeds is challenging
I came across this website about saving Thunbergia seeds. I have not seen the seeds on the flowers before and now I understand why. I will have to watch more closely to see if they are getting pollinated.
Since they are somewhat expensive seeds, I haven’t planted a lot of them. If I save my own seeds, maybe I can get a little closer to a full fence of flowers!