Can plants use moonlight? 

I'm sure it's just my imagine, but when we have a waxing and full moon, the leaves seem just a little bit greener.  Then again, with moonlight and insomnia; come the full moon I'm out in the garden a lot more so maybe it's just extra gardener attention. 

But then it got me thinking about my basic plant biology.  With sunlight, plants absorb carbon from the air to use it as building blocks and at night they absorb oxygen to do their night time things.  If moonlight effects plants, would this also affect their carbon sequestering cycles and other growth factors, or do they just shut their 'eyes' and ignore the moon?

I know it's a foolish question, but insomnia plus no moonlight to garden by makes my brain a bit disconnected in the morning. 

Your question got me curious, so I tried googling.  I didn't come up with much past the "carbon during the day/ oxygen at night" plant biology basics, but I did find this from Cambridge University: http://www.thenakedscientists.com/HTML/questions/question/1769/ .  The part I found most interesting was this:

"I’m sure many of you are familiar with the folding of leaves that we see in the clover growing in your lawns and lots of plants in the garden fold up their leaves at night. Darwin was interested in this and thought that it was to do with the leaves trying to maintain their heat balance at night. What we think is happening now is that the leaves are trying to avoid moonlight so as to prevent their circadian rhythms being disrupted by those very light intensities because they certainly do respond to moonlight."

It kind of makes me wonder how much old agricultural lore about planting, cultivating, and harvesting during certain moon phases might be from generations of growers observing changes in the plant triggered by moon cycles.  I'd really love to see if there's any correlation between when plants begin to flower or when fruit ripens with the phase of the moon (and how it might be affected by day length, and if that contributes to a good year or a bad year for certain crops).   

I don't know much about planting by the moon (I'm with carol deppe on this on in that I plant when there is a break in the weather), but I've noticed when the moon occurs in the year, often corresponds to the weather. 

For example, every year I can remember since I've lived here, if easter is early (easter, for now, is related to the first full moon after the equinox) then spring is early, if it's late then we have an extra long winter.  Same with harvest time, the moons and how close they are to the fall equinox often corresponds to the weather. Also, harvesting and planting at the full moon means we have more hours in the day that we can see what we are doing - gardening by moonlight is awesome, except for weeding. 

But it would be really interesting to see if the moon cycles also affect the plants as well as the farmers.  Moonlight is a different spectrum than sunlight, so I imagine the reaction would be different, or possibly none.