Backyard Discovery publishes "winds up to 100 mph*" across the Bellerose line. The asterisk resolves, further down the page, to: "Product must be anchored as specified in the Backyard Discovery instruction manual." The page never says what anchoring ships in the box.
Greenhouse comparison
Every wind rating here assumes anchoring.One brand includes it.
We read the manufacturer pages — and then the manuals — for five greenhouse kits. Every brand that publishes a wind rating makes it conditional on anchoring, in fine print, in an asterisk, or in a clause most buyers never reach. Only one of them actually ships the anchors. One does not publish its ratings on any product page at all.
- 5 models
- 3 brands
- Manuals read, not just product pages
Planta rates the Sungrow 20 at 60 mph — lower — but qualifies it the same way, "when properly installed and securely anchored", and then includes ground anchors and angle brackets. It states the condition and satisfies it.
The Palram Essence 8×12 publishes nothing on either retailer page. Its ratings exist — 55 mph and 15 psf — printed on the cover of the assembly manual, inside the box. You learn them after you have bought it, and they are the weakest here by some distance.
So the headline number can mislead
On an exposed site, 60 mph with anchors in the box may serve you better than
100 mph with the anchoring left to you. A buyer comparing spec sheets alone cannot
see that difference — which is the entire reason this table exists.
And the Essence hides a second condition
Its manual states that anchoring is "required to complete this stage in order for your
warranty to be valid" — and that ground screws and spikes are not
supplied. Skip the separately-sold anchoring kit and the warranty goes with it.
Neither retailer page mentions this.
Side by side
The five kits
Every value links to where we got it. not published means we looked and the manufacturer does not state it — that is a finding about the product, not a gap in our research. Hover any cell for the caveat.
| Specification | Backyard DiscoveryBellerose 9x6 | Backyard DiscoveryBellerose 11x7 | Backyard DiscoveryBellerose XL 13x11 | Palram CanopiaEssence 8x12 | PlantaSungrow 20 (Gen III) |
|---|---|---|---|---|---|
| Size | 9x6 | 11x7 | 13x11 | 8x12 | 10x20 |
| Floor area | 54 sq ft src | 83 sq ft src | 143 sq ft src | 96 sq ft src | 200 sq ft src |
| Frame | cedar src | cedar src | cedar src | aluminium src | hot-dip galvanised steel src |
| Glazing | 4-wall polycarbonate src | 4-wall polycarbonate src | 4-wall polycarbonate src | 4mm clear twin-wall polycarbonate src | 6mm UV-protected polycarbonate src |
| Panel thickness | 10 mm src | 10 mm src | not published | 4 mm src | 6 mm src |
| Wind rating | 100 mph src | 100 mph src | 100 mph src | 55 mph src | 60 mph src |
| …which assumes | Product must be anchored as specified in the Backyard Discovery instruction manual src | Product must be anchored as specified in the Backyard Discovery instruction manual src | Product must be anchored as specified in the Backyard Discovery instruction manual src | Anchoring is mandatory: 'Anchoring this product to the ground is essential to its stability and rigidity. It is required to complete this stage in order for your warranty to be valid.' src | when properly installed and securely anchored src |
| Anchoring included | — | — | — | No src | Yes src |
| What ships for anchoring | not published | not published | not published | none supplied — manufacturer anchoring kit sold separately, or ground screws/spikes (explicitly not supplied) src | included ground anchors, or angle brackets to secure to an existing foundation src |
| Snow load | — | — | — | 15 psf src | 75 psf src |
| Snow depth | 30 in src | 30 in src | 30 in src | not published | not published |
| Roof vents | not published | not published | not published | 2 src | — |
| Side / end vents | — | — | — | 0 src | — |
| Opening windows | 1 easy-open window(s), manual src | 2 easy-open window(s), manual src | 4 easy-open windows, manual src | not published | — |
| Powered fan included | Yes src | Yes src | Yes src | No src | — |
| Panel retention | not published | not published | not published | not published | not published |
| Warranty | 5 years src | 5 years src | 5 years src | 5 years src | — |
| Expandable | — | — | — | — | Yes src |
| Live price | checking… | checking… | checking… | checking… | checking… |
Prices are advertised prices, fetched live. Shipping is only added where a retailer states it, so a delivered price is shown only when it is genuinely known.
Why these rows
What actually decides whether it survives
We picked these specifications by reading what greenhouse owners actually argue about, not by copying retailer filters.
- Wind, and its conditions
- The most common structural worry among owners by a wide margin — and it is usually fear of losing the whole structure, not of gradual damage. The rating alone is close to meaningless without the anchoring it assumes.
- Snow depth, not pounds
- Backyard Discovery publishes total pounds — 3,700, 5,700 and 9,200 across the three Bellerose sizes — alongside a constant 30 inches. Pounds scale with roof area, so inches is the figure that compares between models. We do not convert to psf, because that arithmetic would be ours, not the manufacturer's.
- Ventilation, counted honestly
- The Essence has two roof vents and zero side or end vents for 96 sq ft, and ships no fan. Owners in hot states report interior temperatures well above 100 °F even with powered fans running. Stock ventilation is routinely the first thing people have to upgrade.
- Panel retention
- How the glazing is actually held in — clips, screws, or a channel. Panels working loose is the characteristic failure of cheap kits. Not one of these five publishes it, which is itself worth knowing before you buy.
Honest limits
What this page is not
These are manufacturer-published figures, reported and linked. We have not tested any of these greenhouses, and reporting a rating is not endorsing it. Local wind, snow, permitting and foundation requirements vary enormously — confirm anything that matters with the manufacturer and your local building authority before you buy.
Five models is a start, not a database. We are researching the models buyers actually name, and this table grows as that work lands.
Found something wrong — especially if you make or sell one of these? Tell us and we will fix it.