Tree Trunk

AKA The Bastion: Get plant strength from the inside out. .

Build thicker stems, stronger branches, and stress-resilient growth across any system with our concentrated, potassium silicate formula.

Strengthen plant cell walls naturally
Get thicker stalks & stronger stems
Stop your plants collapsing under heavy fruit or flowers
No harmful PGRs — safe for all plants
Works in soil, coco coir, hydroponic systems, and aquaponics

$17.97

Size

Stronger stalks. Resilient plants. No stress..

Designed for stronger plant structure, built-in stress resistance, and better yields, without risking nutrient burn. Tree Trunk makes silica supplementation safe and simple — reinforcing your plants where it matters most.

“Didn’t need to stake anything this round. Tree Trunk held it all up.”

Easy to use: Just mix with water. Compatible with your full nutrient plan.

Works in any setup: Use with oil, coco coir, hydroponic systems, aquaponics, and raised beds.

Trusted by thousands: One of our top-rated products, with happy gardeners that keep coming back. .

Visible results fast: Our gardeners report thicker stalks and knuckling within a few feeds.

Safe for all plants: No harmful PGRs. Just clean, high-quality potassium silicate.

Supports structural growth: Builds stalk strength from the inside out using 6.7% silicon dioxide.

Easy to use: Just mix with water. Compatible with your full nutrient plan.

Works in any setup: Use with oil, coco coir, hydroponic systems, aquaponics, and raised beds.

Trusted by thousands: One of our top-rated products, with happy gardeners that keep coming back. .

Visible results fast: Our gardeners report thicker stalks and knuckling within a few feeds.

Safe for all plants: No harmful PGRs. Just clean, high-quality potassium silicate.

Supports structural growth: Builds stalk strength from the inside out using 6.7% silicon dioxide.

See How It Works

What’s inside?

Tree Trunk delivers 6.7% silicon dioxide via potassium silicate — one of the most concentrated, plant-available sources of silica available.

Silicon is a strength nutrient — think of it as the silent architect. It thickens stalks, reinforces cell walls, and helps plants stand up to heavy fruiting and environmental stress

6.7% SiO₂ from Potassium Silicate: Builds structural integrity from the inside out.
Zero Fillers or hidden additives: Clean, transparent, and safe for edible plants.

Pure focus: No added NPK, just targeted strength support for every plant in your garden.

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How to use Tree Trunk in 5 simple steps.

1

Start in Veg: Use from the start of the growth cycle through flower

2

Mix 2.5–5 ml per gallon of water (5ml = ~1 tsp)

3

Shake well before each use(separation is normal)

4

Add after your base nutrients, not in concentrate form

5

Feed with every or every-other watering

For every system. Every setup. Trunk Trunk fortifies wherever your plants grow.

The fortifier your plants need.

Flimsy branches mean wasted potential — smaller yields, broken limbs, and more support work. Tree Trunk strengthens at the structure, giving your plants the resilience they need to support your biggest harvest yet..

"The branches on my 2024 grow were sturdier than any season before."

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Visible victories from gardeners like you.

Customer Feedback

Tree Trunk FAQs.

Tree Trunk supplies potassium silicate, delivering essential silicon (6.7% SiO₂) to reinforce plant cell walls. This helps stalks grow thicker, boosts branch strength, and improves resistance to heat, wind, and environmental stress. It’s especially valuable during heavy fruiting or flowering when structural integrity is key.

Yes.Tree Trunk is fully compatible with Humboldts Secret Base A&B and other popular feeding regimens. Just make sure to dilute it into water before adding other nutrients. Avoid mixing concentrates directly.

Use Tree Trunk with every or every-other watering throughout your grow. Starting early helps develop a stronger foundation, but it’s also effective mid-cycle to reinforce late-stage growth.

Absolutely. Tree Trunk liquid silica fertilizer works across all grow mediums including potting soil, coco coir, hydroponics, aquaponics, raised beds, and more. It's designed to integrate seamlessly into any system.

Yes. Tree Trunk contains no harmful or banned plant growth regulators (PGRs) and is safe for use on herbs, vegetables, fruit trees, ornamentals, and houseplants.

At the maximum dose of 5ml per gallon, a 32oz bottle makes about 189 gallons of solution. That’s weeks of feeding for most home or hobby gardeners.

No. Tree Trunk is great if you’re looking for how to thicken plant stems naturally. For carbohydrate-rich bloom support, we recommend pairing it with Sweet & Sticky. For flower density and yield, try Flower Stacker. Each product plays a specific role.

Grow stronger plants from the inside out.

Over one hundred thousand gardeners trust Humboldts Secret. Tree Trunk is safe, potent, and powerful — giving your plants the support they need to stand taller, carry heavier yields, and thrive..

Try Tree Trunk now — Risk-free.

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