photosynthesis-ish question

[wjcmpbll]

Hi all.

Noob gardener here. I posted a few things about 2 months ago and got a ton of good help. Now I have another question that I can't seem to find the answer to. I admit I haven't exhausted all the threads to find an answer, but I really don't even know where to begin looking. The reason I'm posting it here is because it concerns a tomato plant. Anyhow...

Does anyone know if the leaves of a plant will absorb light effectively from the underside of the leaves? I find contradictory info online.

I ask because I kept one cherry tomato plant inside under a fluorescent light and I'm training it to grow horizontally along the length of the light (until it reaches the window - I hope). In doing so, many of the established leaves and branches are now basically upside-down; the bottoms of the leaves are up toward the light (does that make sense?) I know that time will tell if the plant does well, but I thought it wouldn't hurt to ask, so that I might know what to expect. My assumption is that the leaves and branches will twist and curl so that the tops are facing the light again - maybe?

Feel free to re-categorize this question if necessary and Thanks for any input. Yall are the only reason any of my plants have lasted this long.

[TZ -OH6]

The leaf cells are more or less clear so light passes through until it hits chlorophyll, so Yes, more or less equal photosynthesis for top and bottom of the leaf.

The bottom side of the leaf is not as green as the top because air spaces in the lower leaf tissue scatters the reflected green light, sort of like frosted glass.

[wjcmpbll]

Thanks for the info, TZ. That's what I was hoping for.

And sure enough, when I got up this morning I saw the plant had twisted itself so that more of its leaves are facing upward. Because the plant wants to grow up, it's a daily challenge to rearrange and manipulate it to grow horizontally along the light. (The light is still supplying energy to other plants, otherwise I would hang the light vertically).

I hope it's not bad for the tomato plant if many of its leaves are in contact with the fluorescent bulb. (?)

[TZ -OH6]

The heat from the bulbs is not good for them. Its not enough to burn the leaves but it can be enough to screw up the efficiency of the photosynthesis, and perhaps dry out the leaf as well. It would be better to raise the lights and surround the plant with reflective material. If you want to train the plant you can tie it onto sticks or wires and get whatever shape you want.