how
Engineered the
GREENSTALK VERTICAL PLANTER
the problem
NO FULL-SCALE VERTICAL GROWING SYSTEM ON THE MARKET
When Moldesign co-founder Jack Peterson wanted to try vertical gardening in 2013, he discovered a gap in the market. Alongside his son Ryan, now Moldesign’s lead engineer, they researched what was available and came up short.
Small herb planters that couldn't handle real vegetables
WHAT THEY FOUND
Expensive DIY contraptions with tubes and complicated parts
YouTube videos of gardeners drilling holes in 5-gallon buckets
PEOPLE CLEARLY WANTED A VERTICAL GROWING SOLUTION, BUT NO GOOD SOLUTION EXISTED...
the challenge
Design a planter that could hold a comparable 5-6 gallons of soil per tier, stack securely, nest for packaging, survive for years outdoors, and water efficiently without pumps or tubes. Accomplish this while keeping manufacturing costs reasonable.
the solution
ENGINEERING FOR REAL-WORLD PHYSICS
AND IMPERFECTIONS
Design Constraints Come First
Most inventors think about solving their specific problem. The Moldesign team thought holistically: How will this be packaged? Used by everyday customers? Will it last for years in the sun?
UV resistance testing for sun exposure
material
testing
process
Freeze-breakage tests in actual freezers
Food-grade certification for edible crops
Multiple plastic formulation comparisons
FLOW ANALYSIS BEFORE CUTTING STEEL
Before full-scale mold-making, they used flow analysis software to simulate how plastic would fill the mold. Molten plastic fills the GreenStalk mold in just 2 seconds. At that speed, poor design creates burn marks or flow lines.
Wall thickness became a balancing act. Too thin? Breaks easily and won’t last. Too thick? Expensive, heavy, won't nest for shipping.
THE BREAKTHROUGH
Surface Tension Watering
The biggest innovation wasn't the planter shape — it was the watering system. It needed to distribute water evenly across all tiers without tubes, pumps, or complicated parts that could clog or fail. "We came up with this simple cone," Ryan describes. "The water flows through, and surface tension causes the water to stick to the cone. Then that water fills up the next tray."
No tubes to clog
why
it works
No ports to clean
No pumps to maintain
Water naturally follows the engineered path
ITERATIVE PROBLEM-SOLVING
Drain Holes and fill points
Water has surface tension — it’s possible to have an open hole with water behind it that won't drain due to surface tension. The team tried 5-6 different drain hole designs before arriving at the current design..
The cone interface between tiers presented another challenge. Early versions required near perfect alignment. The solution was to design for imperfection. The current design shoots water at an angle, making perfect alignment unnecessary. This makes customer success much more automatic. The angled flow hits the next cone's side, surface tension takes over, and it works regardless of alignment.
the solution
A DECADE OF PERFORMANCE
TIMELINE TO MARKET SUCCESS
In the early years, the team rented trucks and hauled products to shows. They refined, iterated, and expanded offerings based on customer feedback.
2014
2015 - 2019
2020 - Present
First production samples, local garden show sale
Brand building, design refinements, accessories expansion, direct sales only
First profitable during COVID surge (6-7 years after launch), sustained
The partnership continues today. As GreenStalk customers identify new gardening challenges, Moldesign continues to create molds for new innovations, including seed starting systems, greenhouse covers, and other accessories since the launch of the planter.
WHAT WE LEARNED
This project taught us what many inventors and manufacturers never learn: what it actually takes to launch a product successfully. Marketing, timing, distribution, packaging — they all matter as much as manufacturing efficiency.
That experience shapes how Moldesign works with inventors today. We help customers answer the hard questions needed in bringing their product to market. We are confident we can solve the manufacturing question. But a successful product requires more than a good part.
What Moldesign Brings to Your Project
We deliberately position ourselves as an approachable shop where you talk to real people, not corporate hierarchies. "Many mold makers avoid working with inventors," Ryan says. "It can be too costly for a one-off project. However, we enjoy the process of making new ideas a reality and we have the resources to do it well."
Moldesign brings 40+ years of custom mold-making experience to every project. Whether you're an inventor with a vision or a company refining an existing product, we offer engineering precision and honest consultation backed by real product launch experience.
In-House Capabilities
Custom mold design and building
Flow analysis software
Material testing and selection
Projects range in size from microscopic to as large as 3ft.
Beyond
Manufacturing
Packaging design consultation
Helpful go-to-market feedback
Long-term iteration support
Real product launch experience
How can we help design your story?
Connect with our engineering team to explore how we can deliver create molds perfectly suited for your needs.
Email
Phone
865-588-3774
Location
4720 Middlebrook Pike
Knoxville, TN 37921