Luke set up the cauldron and lit the flames.
He added dew collected on a full moon night to the pot. Once the water boiled, he stirred in two spoonfuls of wormwood infusion, swirling it six times clockwise and then six times counterclockwise.
Next, he added six drops of earthworm juice, stirring once clockwise and once counterclockwise after each drop until the liquid fully absorbed it. The mixture turned green, emitting a bitter yet earthy fragrance.
At this stage, Luke lowered the heat and added ten drops of dragon blood one by one. The liquid turned red, then simmered at a low temperature for three days. Afterward, he added figs and continued boiling for another day.
He removed the heat, filtered the potion three times to remove impurities, then boiled it again. Seven drops of giant spider venom were added, stirred seven times clockwise and once counterclockwise. After a vigorous fifteen-minute boil, he tossed in seven strands of Legolas's generously donated hair.
Originally, unicorn hair was supposed to be used, but since unicorns didn't exist in this world, Luke improvised with elf hair—and, unsurprisingly, it worked.
He then removed the cauldron from the fire and let it cool naturally, leaving it untouched for seven days.
On the seventh day, the liquid had transformed into a bright, silvery fluid resembling mercury.
At last, the growth potion—designed to accelerate the growth of magical herbs—was complete.
Luke poured the potion into crystal vials, filling three bottles, which he stored in an empty cabinet in the potion room. Growth potion was an obscure concoction, primarily used to hasten the growth of magical plants. Only herbology experts or plantation owners specializing in magical flora were familiar with it.
Luke had only learned to brew this potion after inheriting the knowledge and memories of Professor Sprout, a master herbologist. With the potion finished, he eagerly grabbed one vial and left the potion room.
He exited the tower and stepped outside.
The dwarven craftsmen were hard at work constructing the castle, their mechanical pulleys whirring with efficiency. The foundation of a grand fortress, spanning the entire mountaintop, was already taking shape.
And then there was the dragon—cutting costs by airlifting massive stones and timber from afar, drastically reducing labor, material expenses, and logistical burdens.
Luke didn't disturb them. Instead, he headed to the garden area designated by Balin, the castle's architect.
At the garden's center lay a magically protected zone—off-limits to everyone except Luke himself.
This was where the seeds of the White Tree of Gondor and the Mallorn tree were buried.
Luke had arranged the planting sites into raised flower beds with brick borders.
Now, two tender sprouts had emerged from the soil, one in each bed, spaced a hundred meters apart.
These sprouts were extraordinary, radiating an overwhelming vitality.
The golden Mallorn sprout shimmered under the sunlight, exuding a warm energy like a tree of the sun.
Meanwhile, the silver-white White Tree sprout emanated a sacred, cool aura, resembling a tree of the moon.
Gazing at the two sprouts, Luke's eyes sparkled with anticipation.
Since planting the seeds, he had regularly watered them with the enchanted stream water gifted by Lady Galadriel. Yet, the seeds had taken an agonizingly long time to sprout, making Luke fear something had gone wrong.
It wasn't until a few days ago that the sprouts finally appeared, much to his relief.
Now, Luke took out the freshly brewed growth potion and dripped a single drop onto the Mallorn sprout.
The sprout absorbed the potion eagerly and, before Luke's hopeful eyes, began growing at a visible pace. Within moments, it transformed from a tiny sprout into a half-meter-tall sapling.
A single drop of the growth potion equaled a month's worth of growth.
Seeing the Mallorn respond so well, Luke's eyes lit up. Without hesitation, he added ten more drops.
The tree surged upward, swiftly surpassing Luke's height and continuing to expand as if time itself had accelerated.
Nearby, the dwarven craftsmen, busy with their work, suddenly noticed something blocking the sunlight. When they turned to look, their jaws dropped in shock.
A towering tree, already twenty meters tall, stood at the garden's center—and it was still growing.
The tree was majestic and breathtaking, its bark a silvery-gray, its form tall and straight.
It was the most beautiful tree the dwarves had ever seen!
The eldest among them, Balin, recognized it immediately.
"A Mallorn from Lothlórien! Truly as magnificent as the legends say!"
What astonished him even more was that Luke had not only managed to grow a Mallorn on Weathertop but had also made it flourish so rapidly.
But soon, another shock followed. A hundred meters away, a silver-white tree began rising just as swiftly.
Unlike the straight and regal Mallorn, this tree had twisting, dragon-like branches. Its lush leaves were emerald-green like jade, their undersides gleaming silver, casting a soft, ethereal glow under the sunlight. It exuded an aura of nobility and sanctity.
Now, two magnificent trees—one gold, one silver—stood in the garden, brightening the surroundings and freshening the air. Up close, Luke could feel the magical energy thickening around them.
The White Tree's influence was especially profound. Wherever its presence reached, life thrived—grass grew lush and evergreen, flowers bloomed endlessly, and even the air felt invigorating.
Luke still had half the growth potion left, but he refrained from further accelerating the trees' growth.
The potion wasn't a cure-all. Overuse would deplete the trees' innate vitality, doing more harm than good.
Instead, he plucked a few leaves from both trees.
The White Tree's leaves could heal wounds, neutralize toxins, and dispel dark magic.
The Mallorn leaves, meanwhile, were used by the elves of Lothlórien to wrap lembas bread, preserving it for long periods.
Lembas itself was made from Mallorn fruit—a single bite could sustain a traveler for an entire day, restoring stamina and hastening recovery. It was essentially Middle-earth's version of a super-compressed ration.
Luke planned to use the leaves as additional ingredients for future potions.
With the two trees now thriving, Luke didn't leave just yet. Instead, he reluctantly pulled out a pouch, wrinkling his nose.
After casting a Bubble-Head Charm to block the smell, he emptied the pouch's contents at the base of the trees.
It was dragon fertilizer, Smaug's number two—the most potent nourishment for magical plants.
Hogwarts' herbology classes often used dragon dung to aid growth, and Professor Sprout had been particularly fond of it. And since this batch came from Smaug himself, its effects far surpassed that of ordinary magical dragons.
To ensure the White Tree and Mallorn grew strong, Luke had no choice but to endure the stench and fertilize them.
He had even designated a special "toilet" area for Smaug, much to the dragon's bewildered amusement.
After burying the fertilizer and covering it with soil, Luke quickly retreated, casting multiple Scouring Charms on himself—yet still, a faint odor lingered.
Returning to the tower, he headed to the sixth-floor herb garden.
Stepping into the room where the King's Grass grew, he was greeted by warm air and a vast space—several times the size of a football field, with a sky-painted ceiling. Sunlight bathed the area, a gentle breeze rippling the lake's surface, where water lilies swayed.
The once-barren space had transformed into a thriving ecosystem. Grass, flowers, and shrubs covered the ground, butterflies fluttered among blossoms, and fish darted through the lake.
The King's Grass, which had once looked withered, now flourished, even sprouting new leaves.
Luke conjured a watering can, diluted some growth potion, and sprinkled it over the plants.
Under the potion's influence, the King's Grass rapidly grew, flowered, and produced seeds.
Once the seeds matured, Luke collected and scattered them in a new patch, watering them again.
Soon, the original hundred plants had multiplied into an expansive field.
"With this many, I'll never run short again," Luke murmured in satisfaction.
He then applied dragon dung fertilizer to further enrich the soil.
Remembering something else, he waved his wand. "Point me!"
A beam of light shot out, leading him to a spot on the opposite hillside.
There, hidden among the grass, was a certain plant.
Luke grinned. "So this is where you've been hiding!" He grabbed it by the leaves and yanked it out—revealing the Mandrake he had cultivated earlier.
When first planted in this room, the Mandrake had been tiny. Now, fully grown, it was furious at being uprooted.
It wriggled violently, screeching a cry that would have been lethal to anyone unprotected.
But Luke had already cast a Silencing Charm on himself. Chuckling, he teased the Mandrake, ignoring its angry glare.
Once he'd had his fun, he used a dropper to feed it three drops of growth potion.
The Mandrake stopped screaming, smacking its 'lips'—apparently enjoying the taste—and stared at him expectantly.
"Greedy little thing," Luke laughed, giving it three more drops before placing it back in the soil.
The moment it touched the ground, the Mandrake burrowed in eagerly, sprouting purple flowers almost instantly.
The flowers withered, replaced by three small, apple-like orange fruits.
Once ripe, Luke harvested them, carefully slicing them open to extract the seeds.
Mandrake fruit was a rare, top-tier potion ingredient. He stored the flesh in crystal vials and planted the seeds, watering them with more growth potion.
Soon, three new Mandrakes sprouted—naturally magical, requiring no extra effort to cultivate.
Luke didn't forget to fertilize them with dragon dung before leaving.
With the King's Grass and Mandrakes now self-sustaining, he moved on to other rooms, repeating the process—accelerating growth with potion, then enriching the soil.
By the time he exited the herb garden, both the growth potion and fertilizer were spent.
But the results were worth it.
From now on, his supply of magical plants was secure—completely self-sufficient!