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dfollett · March 27, 2017

Karen - and anyone else who might know.....,

I've been puzzling over something recently, and since you're an expert, I'll ask you...

What I have noticed is purely anecdotal, as I have done no scientific or controlled experiments. However, it seems to me that I have significantly more leaf problems on plants with larger, more rugose, heavier leaves (especially PL) than I do with their finer leaved cousins.

My original assumption was that the larger leaved plants should do better in a low-light condition because the larger leaves would absorb more light - or at least have the ability to take in more light than those with the finer/smaller leaves. I figured that larger leaves would give that plant an advantage. However, I seem to have significantly more problems with bottom leaves shriveling up and dying on those that have 'larger/denser' leaves than the finer leaved ones.

In reasoning through how to ask the question, I came up with something that may hold the answer the question for me. Does each leaf need direct light to stay healthy?

If that is the case, then perhaps the denser leaf covering above shades the lower leaves so thoroughly that they die from lack of light. Outdoors there would be much more reflected ambient light reaching all the leaves - and the daily passage of the sun across the sky would allow direct sunlight to reach nearly every leaf on the plant at one time or another. Indoors, the light never changes position and the dense leaves effectively permanently shade their lower brothers (or sisters).

Perhaps, on the plants with the finer leaves, the stationary light above is still able to penetrate and reach the lower leaves - at least enough so that they remain healthier. I have some extra-fine leaf micros that seem to be doing much better overall as a group than those with the more dense leaf structure. Their leaf structure is very much like Silvery Fir Tree (although there is no SFT in their parentage).

I certainly don't have a large enough sample size to be able to say anything definitively. However, after having reasoned my way through the question and then this theory, it kinda makes sense to me. (Sometimes I have to talk my way through something before I know what I think about it....)

Does any of that make sense? Or, should those with more leaf surface area be expected to do better under lights like I originally reasoned?

March 27, 2017	#132
dfollett Tomatovillian™ Join Date: Dec 2012 Location: Utah Posts: 693	Does each leaf need light to be healthy? Karen - and anyone else who might know....., I've been puzzling over something recently, and since you're an expert, I'll ask you... What I have noticed is purely anecdotal, as I have done no scientific or controlled experiments. However, it seems to me that I have significantly more leaf problems on plants with larger, more rugose, heavier leaves (especially PL) than I do with their finer leaved cousins. My original assumption was that the larger leaved plants should do better in a low-light condition because the larger leaves would absorb more light - or at least have the ability to take in more light than those with the finer/smaller leaves. I figured that larger leaves would give that plant an advantage. However, I seem to have significantly more problems with bottom leaves shriveling up and dying on those that have 'larger/denser' leaves than the finer leaved ones. In reasoning through how to ask the question, I came up with something that may hold the answer the question for me. Does each leaf need direct light to stay healthy? If that is the case, then perhaps the denser leaf covering above shades the lower leaves so thoroughly that they die from lack of light. Outdoors there would be much more reflected ambient light reaching all the leaves - and the daily passage of the sun across the sky would allow direct sunlight to reach nearly every leaf on the plant at one time or another. Indoors, the light never changes position and the dense leaves effectively permanently shade their lower brothers (or sisters). Perhaps, on the plants with the finer leaves, the stationary light above is still able to penetrate and reach the lower leaves - at least enough so that they remain healthier. I have some extra-fine leaf micros that seem to be doing much better overall as a group than those with the more dense leaf structure. Their leaf structure is very much like Silvery Fir Tree (although there is no SFT in their parentage). I certainly don't have a large enough sample size to be able to say anything definitively. However, after having reasoned my way through the question and then this theory, it kinda makes sense to me. (Sometimes I have to talk my way through something before I know what I think about it....) Does any of that make sense? Or, should those with more leaf surface area be expected to do better under lights like I originally reasoned?