Methodology

How we pick

Everything on this site is computed from published figures. This page is the arithmetic, the constants, the sources, and an honest list of what we have not done.

By Scooter M., enthusiast · Published September 2, 2026

What we have not done

This comes first because it is the part that decides how much weight everything after it should carry. Pot & Prop has not tested any of the 82 products on this site. There is no test bench here, no scale, no light meter, no room full of stands being loaded until something gives. Nobody here has handled any of these products.

Everyone in this category says they tested twenty stands. We have not tested any, and we say so. What we did instead is the rest of this page.

What we did instead

Collected every published figure. Weight ratings, dimensions, tier counts, pot fit, wattage, color temperature — whatever each listing states. Where a figure is absent, that absence is treated as a finding and recorded, not filled in.
Computed what a watered pot of each size actually weighs from published potting mix densities, using one model applied identically everywhere on the site.
Checked every published rating against that weight at a stated margin, so two products are always compared the same way.
Computed plants per square foot of floor from published dimensions, because in a small apartment that is the figure that decides whether a stand earns its space.
Showed the arithmetic on the page, next to the claim, with the sources linked — so any figure here can be reproduced from public references in about ten minutes.

The pot volume model

A standard-proportion plant pot is a truncated cone. We model it as a frustum whose base diameter is 0.75 times the rim diameter and whose height is 0.85 times the rim diameter, filled to 90 percent of that height — a soil line about an inch below the rim, which is where anyone who has watered a plant indoors fills to.

V = 0.9 x (pi x h / 12) x (D^2 + D x d + d^2)
  where h = 0.85D and d = 0.75D
V = 0.46315 x D^3 cubic inches

It depends only on the rim diameter, which is the one dimension every listing publishes and the one measurement any reader can take with a ruler.

Where the model is wrong

Squat decorative bowls hold less than the model says, so our figures run generous for them. For a safety calculation that is the correct direction to be wrong in.
Tall straight cylinders hold more, so our figures run light. Add roughly a third if your pot is a cylinder.
The pot itself is not included, and it is not negligible above about 10 inches in ceramic or clay. Plastic is close to nothing.
The plant is not included. A mature trailing specimen adds real weight and there is no published data to estimate it from.
Chunky bark and pumice mixes are lighter than peat-based mix both dry and wet, so our figures are conservative for aroid growers.

The constants, and where each comes from

Constant	Value	Source
Dry potting mix, published range	15 to 30 lb/cu ft	Published mix-weight reference
Saturated potting mix, published range	40 to 60 lb/cu ft	Published mix-weight reference
Water	62.4 lb/cu ft	Physical constant
Our dry planning figure	22 lb/cu ft	Midpoint of the published dry range
Our saturated planning figure	55 lb/cu ft	Upper-middle of the published saturated range
Our safety margin	1.5x	A stated design decision, not a measurement

Component bulk densities behind the mix figures come from Cornell's greenhouse media reference. Note the sanity check on the top of the saturated range: saturated mix cannot weigh more than water, and 60 lb/cu ft sits comfortably below 62.4.

Why 55, and why 1.5x

Fifty-five is the upper-middle of the published saturated range rather than the midpoint, and erring high is deliberate: it is the only defensible direction for a load calculation. Understating what a pot weighs is how a shelf ends up on the floor; overstating it costs a reader nothing but a slightly sturdier purchase.

The 1.5x margin covers three things the mix weight leaves out — the pot, the plant, and the shock load of setting a pot down rather than lowering it. It is a judgment, it is stated rather than hidden, and it is applied identically to every product so comparisons stay honest.

The table this all produces

Potting mix weight by pot size, computed
Pot size	Mix volume	Dry	Watered	Rating needed
4 in	0.017 cu ft	0.4 lb	0.9 lb	2 lb
5 in	0.034 cu ft	0.7 lb	1.8 lb	3 lb
6 in	0.058 cu ft	1.3 lb	3.2 lb	5 lb
8 in	0.137 cu ft	3 lb	7.5 lb	12 lb
10 in	0.268 cu ft	5.9 lb	14.7 lb	23 lb
12 in	0.463 cu ft	10.2 lb	25.5 lb	39 lb
14 in	0.735 cu ft	16.2 lb	40.5 lb	61 lb
16 in	1.098 cu ft	24.2 lb	60.4 lb	91 lb

Potting mix weight by pot size, computed. Potting mix only — your pot and your plant sit on top of these figures. Watered weight uses 55 lb per cubic foot, the upper-middle of the published saturated range; the rating-needed column applies this site's 1.5x margin. Where these numbers come from.

Plants per square foot

The second computed figure on the site, and the one no competitor publishes. It is positions divided by footprint in square feet, taken from each listing's own published dimensions. A five-tier corner frame on a 17 by 17 inch base holds five plants on 2.01 square feet, which is 2.5 plants per square foot. A 41-inch pedestal holds one plant on one square foot. Both are legitimate purchases and they are not the same product.

How products get chosen

Does the listing publish a figure we can check? A published weight rating is rare in this category — 11 of 82 products on this site publish one — and its presence moves a product up. Its absence is stated on the page rather than quietly ignored.
Does it clear the arithmetic? Published rating against computed pot weight at 1.5x. A product that does not clear is not disqualified; it is recommended for the pot size it does clear, and the page says which.
Does it suit a renter? No drilling, or a reversible fixing, wherever a no-drill alternative exists.
Does it use floor efficiently? Plants per square foot, for anything that stands on the ground.
Who is it wrong for? Every pick on this site carries a stated reason to skip it. A roundup where nothing is ever wrong for anyone is a catalog.

Prices

Prices come only from a live data layer refreshed against Amazon, and they are stamped with the date they were checked. When that layer has nothing fresh, the buy button reads “Check price” rather than showing a number. Live pricing is not yet switched on for this site, so no page currently displays a price figure. No price is ever typed into body copy, remembered from research, or carried over from a previous version of a page.

What we will never publish

A rating or review we authored. We have not handled these products, so a first-party star rating would be an invented measurement. There is no Review or AggregateRating structured data anywhere on this site for the same reason.
A testimonial. There are none, real or otherwise.
A fabricated price, spec, or availability claim. Specifications are quoted from the seller's listing and attributed as the seller's claim.
A credential we do not hold. No certifications, no expert panel, no medical or horticultural qualification, no years of experience.

Corrections

If a number here is wrong, it is worth more to us than a compliment. Tell us and we will check it, fix it and note the change. The editorial policy covers how that process works.

Sources for this page

This method is applied across all 54 content pages on the site.