Metal plant pots: Corten steel or aluminum

We took from our product pages the sizes offered in both materials. For Callisto, the size reads diameter × height; for Clio, top diameter / bottom diameter × height; for Daphné, opening × height. Dimensions are in millimeters with the inch equivalent rounded to the nearest inch. Weights are the empty weights shown on each product page, and prices are US prices in the base finish: our signature patina for Corten steel, black RAL 9005 for aluminum, which costs the same as its seven other colors.

Size for size, the aluminum pot weighs about half as much as its Corten steel twin: 1.86 to 1.95 times less depending on the size, even though its 3 mm wall is thicker than the 2 mm of the Corten. A Callisto at Ø 800 × 800 mm (31 × 31 in) drops from 91 lb to 47 lb.

On price, the gap is modest in our US prices: aluminum costs 10% to 18% more than Corten steel across these twelve sizes. On Callisto it ranges from 10% at Ø 600 × 600 mm ($3,790 against $3,450) to 18% on the narrow Ø 350 mm, 1000 mm (39 in) tall column ($3,650 against $3,100); on Clio it stays between 12% and 14%, on Daphné between 10% and 16%.

The real difference is the range. We offer our Corten steel pots in far more sizes, and wider ones:

• Callisto: 23 sizes in Corten steel, from Ø 350 to Ø 1400 mm (14 to 55 in) and from 400 to 1000 mm (16 to 39 in) tall; 9 sizes in aluminum, up to Ø 1200 mm (47 in). The Corten sizes from Ø 800 mm (31 in) are compared on our page of large Corten steel pots.
• Clio: 13 sizes in Corten steel, with a top diameter from 500 to 1000 mm (20 to 39 in); 3 in aluminum, including a 600 / 400 × 600 mm (24 / 16 × 24 in) size offered only in that metal.
• Daphné: the same 4 sizes in both metals, from 600 to 1200 mm (24 to 47 in) tall (see Daphné in aluminum).
• Calypso, our conical pot with a wide rim, comes only in Corten steel, in 12 sizes from Ø 600 to Ø 1000 mm (24 to 39 in): you will find it among our Corten steel pots.

Where every pound counts, aluminum has the edge. A pair of Daphné pots at 600 × 600 × 1200 mm (24 × 24 × 47 in) flanking a patio door weighs 175 lb empty in Corten steel, against 94 lb in aluminum. A Callisto at Ø 350 × 600 mm (14 × 24 in) in aluminum, at 14 lb, can be moved with one hand as the seasons change.

These are empty weights. Filled with moist potting mix, a pot weighs far more than its metal, and it is the soil that makes up the load. On a balcony or a rooftop, have a structural engineer or contractor confirm the load the structure can carry before you set out large pots; our guide on how to choose a Corten steel planter is a reminder that wet soil weighs far more than steel.

On the ground, on a lawn or along a garden path, the weight of Corten steel works in your favor: a large pot planted with a shrub stands up better to the wind.

Corten steel arrives with the signature Cortenys patina applied in the workshop: shades of rust, sienna and amber unique to each pot, which deepen with the seasons. It flatters silver foliage, ornamental grasses and warm-colored blooms.

In aluminum, every pot comes in eight colors at the same price, with a 30% gloss: White RAL 9016, Gray RAL 7016, Black RAL 9005, Blue RAL 5001, Yellow RAL 1005, Green RAL 6018, Red RAL 3020 and Orange RAL 2004. A black or gray pot underlines modern architecture; white brightens a shady courtyard; a bold color makes a statement at the front door.

Both metals are delivered bare, ready to plant. If a plant dislikes heat, line the inside with insulation or a thick landscape fabric: in full sun, any metal warms up.

Corten steel can leave rust runoff on light stone, pavers or a pool coping, especially in its first months. The protective varnish we offer as an option on our Corten pots greatly reduces it without ruling it out: even varnished, a Corten steel pot can still stain the ground. Set it on a saucer, shims or small feet, or on a gravel bed. Our guide to Corten steel care and rust stains covers these precautions.

Powder-coated aluminum does not rust and will not mark the ground. It is the metal we recommend on a pool deck, on very light pavers and near the ocean, where salt keeps the Corten patina from stabilizing; our guide to Corten steel near the sea explains why.

Start with where the pot will stand, then with the size of the plant.

• Balcony, rooftop, a pot you move around: aluminum, half the weight.
• Pool deck, light pavers, oceanfront: aluminum, with no rust runoff.
• A color to match siding or window trim: aluminum, in eight colors.
• Very large diameter, for a tree or an olive tree: Corten steel, up to Ø 1400 mm (55 in) with Callisto, a size not offered in aluminum.
• A tall, narrow pot for an entryway: Callisto at Ø 350 mm (14 in) or Daphné, in both metals.
• The lowest price and a material that weathers over time: Corten steel, from $2,790; aluminum costs 10% to 18% more size for size.