I have March 21st as Flowey's birthday

While it's not on his 13th birthday, just while he's 13 does he start growing leaves, I thought it was nice to post this on Flowey's birthday

This has been added to the chronological order list in the profile

Flowey yawned, opening his eyes as the sky began to lighten. Straightening up on his stem, the little plant looked around, taking in how much space made up his new bedroom. It was weird, having a full room to himself. But it had become weirder sharing a room with his older sister. The new privacy was nice.

The flower stretched his roots and reached for his phone. He didn't feel like climbing all the way downstairs just to go online. He could almost hear Frisk warning him about bright phone screens in a dark room. Something about the contrast being bad for his eyes – but he really didn't care.

He poked at icons and tapped rude comments. A ticklish itch on his stem started to annoy him.

Growling, Flowey attempted to rub it away with a vine.

That's weird. It felt like something was growing out of his stem.

Stretching a vine all the way across the room to the main light switch, Flowey clicked it on.

Looking down, Flowey peered at the things growing out of his stem. He squinted at them. They were very small, but when tried, Flowey was able to curl and wiggle them. They almost kinda looked like – Flowey gasped as he scrambled from his dirt, actually tripping over his own roots a few times as he darted to Frisk's room.

Flowey burst into his sister's room not bothering to climb up onto her bed. Instead he formed a small pellet and launched it at the human.

"Ouch!"

"Frisk! Frisk get up!" He formed and launched another.

"Ow! Jesus!" Clicking on the light, Frisk shoved her glasses onto her nose before her lovely little brother could throw another bullet at her. "What?! What is it?!"

"I'm growing leaves!"

"Really?" Rubbing the bruises darkening on her shoulder, Frisk climbed out of bed and crouched next to the flower. "Hold still! It's hard to see with you wiggling so much." Flowey just managed to stop bouncing on his stem, and curled one of the new little leaves. "Wow! Yeah it's small but it's definitely a leaf!"

Flowey began wiggling excitedly again, his thin roots curling and uncurling in delight. "I didn't think I was gunna grow any! I've been up here for like three years now!"

Picking the flower up, so she could sit on the soft bed rather than the hard floor, Frisk thought about it. "Maybe you grow slowly. You do get a lot of sun." She paused, "Though then again you do prefer candy and junk foods. And you do sometimes still put up a fight over healthy things."

"I get full easy! I'm not gunna waste stomach space on things that don't taste good!" The little flower huffed and folded two of his vines. Then looked down at the tiny leaves and grinned. Soon he might be able to cross those in annoyance!

"You also don't stay in dirt that often despite claiming to like it."

"It's limiting! Underground I could get anywhere – dirt was everywhere! – up here it's either stuck in a large tub or carried around in a flowerpot!" Before Frisk could respond, a tired voice sounded from the hallway.

"What's with all the shouting?"

Flowey turned with a grin to Luna, bouncing on the bed. "Mom! I'm growing leaves!"

"Oh! That's fantastic, Sweetie!" the older woman yawned. "I'll make a special breakfast in a few hours."

Flowey let out a happy little chirp-like sound as Luna returned to her room. Frisk yawned and petted her brother, ruffling his petals slightly. "I'm going to try and sleep a little more, but congrats on the leaves, Bro."