There is also the factor of how old the leaves are. If they are four or taller feet they will grow perhaps another inch or two when damaged, but then stop.

If the leaf is a young one, it will stop in it's tracks. This is why you see older, ratty, stunted leaves in full pots of much fuller plants and they seem to be almost a different species, they are so much smaller.

I heard this, then decided to experiment with it. My mature sans was sitting on a desk top, growing for the ceiling. I decided I didn't want it to get any taller than X and started popping the tips when X was reached. Sometimes I wouldn't always be paying attention, and a few leaves are X+. It is pretty obvious looking at the pot, most of the leaves are the same height, rather than the various heights that can be found in still growing pots of leaves.

By some odd coincidence, I was thinking about this last night! Sans leaves grow from the bases (as evidenced by the one I just brought in from the garage...pale on the new growth) so how on earth can the growth point "know" that the tip has been damaged? I'll believe it if you've experimented and found it to be true, but I want to know the reason behind it...inquiring minds...

I've marked some leaves with light scratches to verify that the leaves grow from the bottoms rather than the tips. I've made 3 paralell scratches 1" apart on some yound leaves (less than 12" tall on a plant with 36" leaves). I'll remove various amounts of tip growth on a couple of young leaves as the develop and see if there is any difference this spring.

This is the best experimental design I could come up with.

We should probably come up with a better experimental design to check this out, but my preliminary observations indicate that removing the growth tip stops leaf growth does not prevent future leaf growth.

Joe 'the scientist' DeRosa

I will again explain how I did this, and what I used as a guide. My sans grew near my roll top desk, which is 4 feet 4 inches tall. I clipped the tips when they topped the desk, except for the four (4) exceptions that you see, that went a few weeks longer. I had thought I worked this out fairly logically, and rationally, but obviously not 'scientifically'...

The broom is exactly 4 feet tall, and a popular, easily available brand. Please compare the height of ALL the leaves to the broom...

The pot is 18 inches across to provide reference, and the broom, four feet tall. Too bad the tape, the camera, and the broom weren't more co-operative together!

Please notice the symetrical height of the majority of the leaves.

{{gwi:1258795}}

How does a fish in an aquarium 'know' to grow this big, and no more? They will fill up the available space, reguardless what you feed them. Sans will grow until they can't anymore (broken against an obstruction) and stop.

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The whole caboodle.
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Interesting! I'm going to go hack off some tips on just emerged leaves and see what happens.

I have that 'same' experiment going already with a four inch tall new leaf that the new cat chewed the tip gone on...