Planto, I'm afraid not. Once a leaf is damaged, it's gone. New growth will not grow on the stem. In fact, you might as well cut the leafless stem closest to the soil line.

The good news is, your PL will continue growing. More leaves will sprout.

We all have a little paranoia in us, lol, Toni

I think it's more of a nuisance than a disaster. Spathiphyllums are pretty easy like that.

Toni and tropicbreezent: thanks for the information!

hexalm: Sorry for my lack of better terminology. Yes, I broke the leaf blade off from the petiole and just the petiole is left. My concern was that if this was the newest petiole created, will me having broken it off, keep the peace lily from producing more petioles/leaf blades? I am suspecting no as the meristem sounds to be a completely different "thing" in a completely different area than the petiole that broke, but I just wanted to clarify my question better. Thanks again.

Planto

I tend to gloss over terminology often enough myself, but was just being extra specific to make sure I understood the question :)

You're correct though, the meristem moves on to its next project once it creates a leaf, so damage to existing leaves shouldn't be an issue and you'll almost certainly see another new leaf soon (in fact, leaf damage like that tends to stimulate new growth).

Planto, hexalm's right. New leaves will grow.

Hex, out of curiosity, why and how does leaf damage stimulate new growth?

I've read damaged/marred leaves should be removed, otherwise nutrients focus on the ruined leaf..

It depends on the type of damage, but in general I think it's a response to herbivores. (Though herbivores browsing on a plant can cause a host of different reactions, including production of compounds to cope better with damage or to discourage herbivores from eating.)

I'm not sure about the exact mechanism, but all I'm really saying is that if you tear a leaf off, the plant needs to replace the leaf. Same concept as pruning.

I think you're right that if the leaf has damage and is still attached (or if its removal caused major damage elsewhere), that can sap resources--if nothing else, just by using nutrients from the roots that could instead be invested in new, nicer leaves.

That's right, if a leaf has its area reduced then it can't take up the same amount of resources from the roots. This then gets channeled to the 'next project', ie a new leaf. If it's only partly damaged then it might still be able to draw off most of the resources thus preventing rapid growth of a new leaf. It's all a matter of degrees.

Chemical messengers give plants a 'sense' of whether parts like leaves and branches are net users or net producers of energy than we have, so while it's fine to remove a few damaged leaves from healthy plants, some consideration should be given to how much photosynthesizing machinery we remove from plants that are struggling. If a plant is clinging desperately to 12 leaves and 6 of them aren't pretty, it's probably better to live with the unsightly foliage than to remove somewhere around half of the plant's ability to make food.

When a leaf becomes a net user of energy, the plant sheds it, and often but not always grows a new leaf from latent buds in the leaf axil (crotch), which is why it's important to cut through the petiole (leaf stem) at some point or through the leaf itself, as close to the stem as possible to avoid damaging a latent bud when removing leaves. Avoid pulling or tearing them off. The plant will soon shed what's remaining of the leaf.

In bonsai, we often cut leaves in half on vigorous branches or toward the top of apically dominant plants to force energy allocation to weaker plant parts. You may have noted a few conversations that included tips on energy management that included removing leaves or cutting back strong areas of plants to force back-budding or more growth in areas that are weaker energy sinks, which is all part of the same theme. I notice that when I'm cutting leaves by a fraction, if I go too far and cut too much of the leaf off, the plant will shed the leaf and grow another.

Leaves shed due to a lack of auxin flow from the leaf. Auxin is produced primarily in apical meristems, but in leaves, too. A continual polar flow (shoots to roots) of auxin across the abscission zone at the base of leaves or petioles is required to keep an abscission layer from forming. Once the leaf is damaged to the degree it is not producing enough auxin to prevent the abscission layer from forming, the layer forms and the leaf is shed. At the same time, the reduction in auxin flow allows another growth regulator to become dominant. The growth regulator, cytokinin, is produced in roots and moves from roots to shoots, opposite the polar flow of auxin. Cytokinin stimulates lateral breaks; that is, it stimulates latent buds into activity. So, as the leaf is being shed due to a lack of auxin, the surge in cytokinin is stimulating a new bud to take the old leaf's place. In some plants, apical dominance is so strong and the flow of auxin so great that this doesn't occur at all.

Al

Thanks for the detail, Al! I figured it was about auxin ;)

hexalm,
Thanks so much for the information!

Planto

The opening sentence was missing a word. It was supposed to read Chemical messengers give plants a better 'sense' of whether parts like leaves and branches are net users or net producers of energy than we have, ....

Sorry it didn't make sense. Still, I hope you found value in the offering.

Al