Does “planting” have any biological impact on the Pequeninos (piggies) lifecycle?

Question

I wonder if "planting" has any biological impact on the Piggies life-cycle, or if it is a ritual to honor Piggies in their society.

I know that Piggies have 3 lives:

The first-life: tiny piggies live inside the mothertree, feed on the sap.

The second-life: After they grow enough, the piggies will climb out of the mother-tree, and start living as a sentient species. Piggies like Leaf-eater, Rooter .... in the book.

The third-life: a tree. When the piggies die, they become a tree.

"Planting" is a procedure by which Piggies who earn passage to the third-life are "butchered" by his best-friend or rival. Then the butchered Piggie's corpse roots into a tree.

Ender is planting a piggie named Human.
Picture taken from ORSON SCOTT CARD'S SPEAKER FOR THE DEAD

I wonder if "piggies" can go to third life if they are not planted, but die in other ways. Is planting just a way to honor others, or it is important for piggies life-cycle? Will something bad happen to them if they are not planted when they die?

The piggie named Human said when Ender ask them to stop the war:

"...This is very hard. Until you humans came, other piggies were-- always to be killed, and their third life was to be slaves to us in forests that we kept. This forest was once a battlefield, and the most ancient trees are the warriors who died in battle. Our oldest fathers are the heroes of that war, and our houses are made of the cowards. All our lives we prepare to win battles with our enemies, so that our wives can make a mothertree in a new battle forest, and make us mighty and great. "

From this quote, I interpret that piggies who are killed in war can go to third-life (being a tree) without planting. Because, in the quote, piggie Human said "our houses are made of the cowards" which I interpret to mean they are the enemy, and they were not planted (because planting is an honor that must be earned, not for cowards). From this evidence, I conclude that the piggies can go to third-life (became a tree) without planting.

However, when Leaf-eater think Miro is going to die when he falls off the fence, he said

"Quick!" shouted Leaf-eater. "Before he dies, we have to plant him!"
...
"Before he dies," said Leaf-eater. "We have to give him root."

This gave me a clue that "planting" is somehow important. It is a "must-have" procedure before someone dies? I feel like it is somehow as important as "first-aid".

Answer 1

Updated answer

• No, the tree would grow even if the piggie isn't planted.

  When visiting the mothers, Ender is warned:

  “And if you harm them,” said Leaf-eater, “we will kill you unplanted and knock down your tree.”

  This means that they expect the tree to grow even if Ender is killed un-planted (this is before he tells them that humans don't have a Third Life).

• However, the dead must be on the ground, based on a threat Shouter made to Ender when they started negotiations:

  “She says you must teach us everything you know, take us out to the stars, bring us the hive queen and give her the lightstick that this new human brought with you, or in the dark of night she’ll send all the brothers of this forest to kill all the humans in your sleep and hang you high above the ground so you get no third life at all.”

• Now, what the "planting" ritual does, is it lets a tree become a father tree - but it's unclear if that's biological or ritual distinction.

  When Human discusses with Ender that Ender must give hime the honor, he says:

  “And if we make this covenant between your tribe and ours,” said Human, “will you give me the honor of the third life? Will you let me rise up and drink the light?”
  “Can we do it quickly? Not the slow and terrible way that—”
  “And make me one of the silent trees? Never fathering? Without honor, except to feed my sap to the filthy macios and give my wood to the brothers when they sing to me?”

  And later, when discussing the signing of the Covenant:

  “I know what you wish, my friend Speaker,” said Human. “To you it feels like murder. But to me—when a brother is given the right to pass into the third life as a father, then he chooses his greatest rival or his truest friend to give him the passage.

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Original answer.

Yes, it seems so. When the pequeninos speak to Miro on the night of the Speaking, and they discuss the birth of 300+ new babies that may have been one of the "bad" things Starways Congress discovered, Arrow said:

. “They saw that food would be plenty,” said Arrow. “Now we’re sure to win the next war. **Our enemies will be planted in huge new forests all over the plain, and the wives will put mother trees in every one of them**.”

And Ender confirms it from what he learned from piggies that day:

“But what if the dead don’t go to heaven? What if the dead are transformed into new life, right before your eyes? What if when a piggy dies, **if they lay out his body just so, it takes root and turns into something else**? What if it turns into a tree that lives fifty or a hundred or five hundred years more?” ... When the piggies kill one of their people, he is transformed into a tree.

And the piggies confirm it themselves when they discuss Human:

Ouanda looked at Ender in surprise, then back at Mandachuva. “I thought everybody liked Human,” she said. “Great honor,” said Mandachuva. “A wise one.” Then Mandachuva poked Ender in the hip. “But he’s a fool in one thing. He thinks you’ll do him honor. He thinks you’ll take him to the third life.” "What’s the third life?” asked Ender.

Answer 2

Planting is important. When Human says that "the most ancient trees are the warriors who died in battle" he means that the planting was done after it was clear that they were going to die, but before they technically died. Once a piggie dies, it becomes too late to plant him.