Why do carambola leaves fold?

[bradflorida]

I'm trying to figure out why my Kari Carambola tree's leaves are often folded almost completely during the day. 

Would too much wind cause the leaves to do this?

Brad

[CoPlantNut]

In my experience, this is from too much wind or when it is too dry or hot.  Wind especially dries it out, so it is often a combination in my arid climate.

   Kevin

[FlyingFoxFruits]

don't the leaves also fold up a night? and during rainy weather?  Even when the tree is happy?

lots of plants do this...like pigeon peas.

[Steve in Los Osos]

My understanding is that carambola leaves behave much like mimosa pudica ("sensitive plant"), although not quite so dramatic. Before its demise, even moving the container my carambola seedling occupied would cause a slight collapse of leaves. Surely a good breeze could have the same effect (or rain, etc.).

[Slopfog]

Leaves of them are very sensitive, no doubt.  I haven't quite figured them out... My tree which is in a 30 gallon container just up and dropped half it's leaves in 3 days.  It had been receiving rain every day, then went a day with no water and two days with me hand watering. Apparently it was not happy. Sure seems to take a ridiculous amount of water.

[thao]

It's natures defensive mechanism, to protect the plant from losing excess moisture/save energy during hot temps. Same reason, why many plant(i.e. banana, papaya, etc.) leaves fold or look wilted in hot temps. It also apply to windy conditions, but i'm not sure exactly why though. Maybe to keep the leaves or plant from being blown over or away?? But I have no clue about when it rains, maybe to save energy as well? The sun is gone so, it close/fold, so it will conserve it's energy, since there is no sun light to be absorb?? Leaves dropping, to conserve energy too maybe??? Just my guess, feel free to make corrections, if you know what it might be. A science/plant botanist person, would probably know something about it.

[bradflorida]

Thanks for the input!  I appreciate it.

Brad

[Steve in Los Osos]

Here's kind of a neat Wikipedia article on mimosa pudica. The mechanism is probably the same or at least similar:

http://en.wikipedia.org/wiki/Mimosa_pudica

[Guanabanus]

A few hours of getting way too dry in a container will make a Carambola drop a bunch of leaves.

Dramatic yellowing and dropping of lower leaves after heavy rains is probably from lack of available soil nitrogen, due to it's having all been leached away.

So, plenty of slow release nitrogen fertilizer or organic matter, and even soil moisture, should keep your tree happier.

[Illia]

The way I see it, this is a natural thing for any Oxalid to do. Out here we have a wild Oxalis sp. and grow an edible Oxalis sp. - Both fold their leaves when it is too hot, too sunny, and/or too dry. Normally Oxalids fold them at night, which they do, but folding by day is a sign of either of those three traits in extreme. I find any Oxalid to prefer a little bit of shade now and then.