Tin Can Planters: Drainage, Rust and Decoration
Turn clean food cans into small planters that last: how to add drainage holes, three ways to handle rust, how to paint or wrap the outside, and which plants suit a small can.
Tutorial at a glance
Materials
- Clean food cans, labels removed
- Brush-on metal primer
- Acrylic craft paint
- Clear water-based sealer (optional)
- Jar lids or saucers
- Small pebbles and potting mix
- Small plants or plastic nursery pots
Tin can planters are easy to make and easy to get wrong. A can with no drainage drowns its plant, and a bare steel can that stays damp turns rusty within weeks. Both problems have simple fixes if you deal with them before the soil goes in.
This guide covers the three decisions that matter: how to add drainage holes, what to do about rust, and how to decorate the outside so the finish holds up to watering.
What you need
- Clean food cans, about 15 oz (425 g) size or larger
- Hammer, a nail about 2 in (5 cm) long and a block of scrap wood
- Masking tape or a strip of cloth tape for the rim
- Brush-on metal primer and acrylic craft paint, or a fabric remnant and glue
- Flat paintbrush
- Jar lids or saucers to stand the cans on
- Small pebbles, potting mix and plants
Prepare the cans
Use cans that held food, such as beans, tomatoes or soup. Cans that held paint, solvents or other chemicals are not suitable for planters. Wash each can in warm soapy water, rinse and dry it right away, inside and out, so it does not start to rust before you begin.
Peel off the label and rub away the glue stripe. Then check the rim. Cans opened with a smooth-edge opener have a rolled, blunt top. Cans opened the ordinary way can have a sharp inner edge or small burrs: press these flat against the wall with the back of a spoon, or fold a strip of tape over the rim all the way around.
The full rim check is described step by step in the tin can pencil holder tutorial, which is a good first can project if this is your first.
Add drainage holes
- Turn the can upside down on the wood block, on a sturdy surface such as a workbench or a concrete step.
- Hold the nail upright on the base, about 1/2 in (1.3 cm) in from the edge, and tap it with the hammer until it breaks through. Pull the nail out.
- Repeat to make four holes spaced evenly in a ring, then add a fifth in the center.
- Turn the can over and look inside. The nail pushes sharp points of metal inward, so keep fingers out of the bottom from now on and use a spoon to press soil down when planting.
Watch out
Making the holes is an adult step. Hold the nail near its head, keep the other hand clear once it has bitten into the metal, and wear eye protection if you have it. Punched metal edges are sharp.
Three ways to deal with rust
Food cans are thin steel with a light protective coating. Once that coating is scratched or punctured, as it is around every drainage hole, damp steel rusts. Rust stains windowsills and eventually eats through the base, so choose an approach before you plant.
| Approach | How it works | Best for |
|---|---|---|
| Prime and paint | Primer and paint on the outside and base slow rust where water sits | Planting directly in the can |
| Plastic liner pot | The plant stays in its nursery pot, which drops inside the can | Herbs, and cans wrapped in fabric or paper |
| Accept the rust | The can is left bare and weathers to a brown, mottled surface | Outdoor shelves and steps |
A liner pot is the tidiest answer. The can acts as a decorative sleeve, the plant lifts out for watering at the sink, and soil never touches the metal. It is also the sensible choice for herbs you plan to cook with, since the roots then grow in a pot made for plants. A 15 oz can fits most small nursery pots of about 2 1/2 to 3 in (6 to 7.5 cm).
If you like the rusty look, keep the can on a saucer you do not mind staining, and expect to replace it after a season or two.
Paint or wrap the outside
Paint grips bare metal poorly, which is why primer comes first. Work in a ventilated room and protect the table with newspaper.
- Brush one thin coat of metal primer over the outside and the base, working it around the drainage holes. Let it dry for as long as the label directs.
- Apply two or three thin coats of acrylic craft paint, letting each dry to the touch, roughly 20 to 30 minutes, before the next.
- Brush on a coat of clear water-based sealer if the planter will be watered in place.
The ridges on a can catch drips, so load the brush lightly and follow the ridges around rather than brushing up and down.
Fabric is the other option. Cut a remnant to the height of the can plus about 1/2 in (1.3 cm), spread tacky glue over the metal, and smooth the fabric around with the seam at the back. White glue alone can let go of smooth metal, and the guide to the best glue for recycled crafts explains which adhesives hold fabric to a can. Fabric-wrapped cans should always have a liner pot, because wet fabric stains and peels.
Plant up the can
For direct planting, build the layers from the bottom: a shallow layer of small pebbles over the drainage holes to keep soil from washing out, then potting mix to about 1/2 in (1.3 cm) below the rim, then the plant, firmed in gently.
Stand the planter on a jar lid or saucer and empty it after watering so the base does not sit in a puddle.
Plants that suit a small can
A food can holds little soil, so pick plants that stay compact or tolerate drying out.
- Succulents: small rosettes and trailing types, in a gritty cactus mix, watered sparingly
- Herbs: thyme, chives and compact basil on a bright windowsill
- Trailing houseplants: rooted cuttings of pothos or spider plant babies
Larger cans, such as the big ones from canned tomatoes or coffee, give roots more room and dry out less quickly.
Tip
Small cans dry out fast in sun. Push a finger into the soil before watering: if the top inch (2.5 cm) is dry, water until a little runs out of the holes.
If keeping up with watering is the hard part, a self-watering plastic bottle planter feeds an herb from a reservoir through a wick and needs refilling far less often.
Frequently asked questions
Do tin can planters need drainage holes?
If you plant directly in the can, yes. Without holes, water collects at the bottom, roots sit wet and the steel rusts from the inside. The exception is a can used as an outer sleeve around a plastic nursery pot: lift the pot out to water it and let it drain before putting it back.
How long does a tin can planter last before it rusts?
It varies with the can, the finish and how wet it stays. A bare can kept damp can show rust within a few weeks, starting around the drainage holes and the bottom seam. Primer, paint and a saucer that is emptied after watering slow this down, and a liner pot slows it most.
Can I paint a tin can without primer?
You can, but acrylic craft paint tends to scratch and peel off bare metal, especially where water runs over it. A thin coat of brush-on metal primer gives the paint something to grip. If you skip it, wash off any grease, apply thin coats and finish with a clear water-based sealer.
