This isn't a knowledge gap on the buyer's side, it's a real structural difference in how the two product categories are classified, and it's worth understanding before placing a bulk order.
How Standard Nursery Container Sizing Actually Works
For plastic and conventional containers, the trade has a shared reference point: the American Standard for Nursery Stock (ANSI Z60.1, recently superseded by ANSI Z60.2-2025), maintained by AmericanHort. Its stated purpose is to give buyers and sellers a shared terminology for specifying plant and container sizes so that a transaction means the same thing to both parties, covering how containers relate to plant size, root ball dimensions, and caliper-to-height ratios. In practice, this shows up as the familiar container class system: container classes numbered #1 through #20 and beyond, where a #1 pot corresponds to roughly one gallon (about 4 liters), with each class number mapped to a standard volume range regardless of which manufacturer made the pot.
Why Coco Pots Don't Fit Neatly Into That System
ANSI Z60.2 was written around rigid, dimensionally consistent containers, largely plastic. Coco pots fall outside its scope for a structural reason: they're molded from a compressible fiber material with wall thickness, taper, and density that vary by manufacturer, so a "gallon" coco pot from one supplier and another aren't guaranteed to hold the same volume.
This isn't a theoretical concern. Even within standard rigid nursery pots, buyers already run into a version of this problem, a reference chart from Grower's Solution shows that a "1-gallon trade" pot and a "1-gallon full" pot from the same size class have noticeably different actual dimensions and volume. Coir-based pots amplify this further because the material itself compresses and expands depending on density and moisture, which is why growers sourcing coco pots have specifically flagged that a "5-gallon" fabric or coco format doesn't necessarily hold the same volume as a rigid 5-gallon container, a distinction that matters much more for a bulk purchase order than for a single home grower.
The practical result: for coco pots, diameter, height, and stated fill volume have to be confirmed against the specific supplier's own measurements rather than assumed from a generic size class.
What "Grade" Actually Means for a Coco Pot
Unlike "size," which is at least measurable, "grade" is a term suppliers use inconsistently. Broken into its real components, it covers three separate properties.
Fiber Density and Wall Thickness
This determines how long the pot holds its shape under regular watering and handling. Coir's inherent durability comes from its lignin content, research in Nature Scientific Reports attributes coir's comparatively low degradation rate to its high lignin concentration relative to other natural fibers, a finding echoed in a review in RSC Advances. But lignin content alone doesn't determine pot durability, how densely the fiber is packed into the pot wall does, and that varies by manufacturer rather than by a shared grading scale.
Washing and Buffering Level
This determines the pot's starting EC, pH, and salt content, which matters if roots will be in direct contact with the pot wall. A published technical specification sheet from coir substrate supplier FarmersOrigin illustrates what this looks like in practice for a pre-formed coir product: documented EC (under 0.7 mS/cm), pH range (5.8 to 6.5), sodium and chloride limits for washed material, and CEC, figures the supplier ties to a batch Certificate of Analysis rather than a general claim. This level of documentation is a reasonable benchmark to ask any coco pot supplier to match.
Binder Type
Most coco pots are held together with natural latex, but the amount and type of binder used affects both cost and how the pot behaves once repeatedly saturated, a variable that isn't captured by size or fiber density alone.
None of these three properties map onto a single industry-recognized "grade A / grade B" scale the way, for example, coir fiber for rope or upholstery has long-established bristle and mattress fiber grades. For coco pots, "grade" is functionally whatever specification sheet the supplier provides, which is exactly why requesting that documentation matters more than trusting a marketing label.
A Practical Way to Specify a Bulk Order
Given the lack of a shared standard, the more reliable approach for a bulk buyer is to specify coco pots the way horticultural suppliers already specify other unstandardized products: by direct measurement and documented properties rather than by class name.
- State diameter, height, and target fill volume in both metric and imperial units, since coco pot manufacturers based in different regions typically default to one or the other, and a "10 cm" pot and a "4-inch" pot are not automatically identical once wall taper is factored in
- Request the wall thickness or fiber density figure, not just a size label, since this is what actually determines handling durability
- Request washing/buffering data (EC, pH) with a batch Certificate of Analysis, following the same documentation standard illustrated in FarmersOrigin's published spec sheet above, rather than accepting "low EC" as an unquantified claim
- Confirm binder type and rehydration behavior, particularly if the pots will be filled and shipped compressed rather than pre-formed
- Ask for a sample batch before committing to full container volume, so actual dimensions and performance can be verified against the specification before the order is placed
Sourcing Coco Pots for Nursery and Export Markets
Cocovex supplies coco pots manufactured in Indonesia for nursery, horticulture, and export markets, with diameter, wall density, and washing/buffering specifications documented and confirmed before shipment. Get in touch to discuss size and grade requirements for your operation.
Sources Referenced in This Article
- AmericanHort / ANSI, ANSI Z60.2-2025 American Standard for Nursery Stock
- University of Florida IFAS, American Standard for Nursery Stock (ANSI Z60.1) overview
- Gardening Know How, Nursery container class sizing (#1 to #20)
- Grower's Solution, Nursery pot size chart
- Rollitup forum, grower discussion on coco pot size inconsistency. Cited as illustrative grower experience, not a technical source.
- Nature Scientific Reports, Thermo-mechanical properties of coir fiber composites
- RSC Advances, State-of-the-art review on coir fiber-reinforced biocomposites
- FarmersOrigin, Fit to Pot technical specification sheet. Cited as an industry example of published specification documentation, not an independent lab study.
Ready to Source?
Get Coco Pots, Direct from Indonesia
Request a sample, get a custom quote, or speak with our export team about size and grade requirements for your operation.