Choosing pots and potting soil: drainage, materials and mixes

Why a drainage hole is non-negotiable

Roots breathe. After watering, excess water must leave the pot so air can return to the spaces between soil particles. Without a hole, water collects at the bottom, the lower roots sit in an airless puddle and rot starts out of sight.

The gravel myth: A layer of gravel or pot shards in the bottom does not improve drainage. Water does not move easily from fine soil into coarse gravel, so it stays in the soil just above the layer. The wet zone simply moves higher, closer to the roots, and the pot holds less soil.

• Choose pots with at least one hole; larger pots benefit from several.
• To stop soil washing out, cover the hole with a piece of mesh or a coffee filter, not stones.
• Raise outdoor pots on feet so the hole is never blocked.

⚠️ If you love a pot without a hole, use it as a cachepot (outer pot) and keep the plant in a plastic nursery pot inside it.

Pot materials compared

The material changes how fast soil dries, how heavy the pot is and how it copes with frost.

Choosing the right pot size

A pot that is too big is a common cause of root rot: the extra soil stays wet long after the roots have taken what they need.

• Repotting: Go up only 1–2 in in diameter for small and medium plants, 2–4 in for large ones (estimated).
• Depth: Most houseplants like a pot about as deep as it is wide. Succulents and shallow-rooted plants are happy in shallower bowls; tomatoes and deep-rooted vegetables need depth.
• Vegetables: A tomato or pepper needs at least 5 gallons of soil; herbs manage in 1–2 quarts per plant (estimated).
• Shape: A pot wider at the top than at the base makes it much easier to slide the root ball out later.

Cachepots: the decorative outer pot

A cachepot is a pot without a hole that hides a plain nursery pot. It lets you use any decorative container without giving up drainage.

• Pick a cachepot slightly wider than the inner pot so you can lift it out easily.
• Put a few pebbles or an upturned saucer inside to keep the inner pot above any drained water.
• Lift the inner pot out to water at the sink, let it drain, then put it back.

⚠️ Check the cachepot 15–30 minutes after every watering; standing water hidden inside is a leading cause of root rot.

What goes into potting mix

Potting mix is not garden soil. Garden soil compacts in a pot and drains poorly; good mixes are light, airy and free of weed seeds. Each ingredient has a job:

Mix recipes by plant group

Ratios are parts by volume and are a starting point (estimated). Adjust for your home: more perlite or pumice if the soil stays wet, more base if it dries too fast.

Houseplants

• 2 parts peat or coir
• 1 part perlite
• Optional: ½ part compost
• For pothos, peace lily, spider plant and most foliage plants.

Succulents and cacti

• 1 part potting mix
• 1 part pumice or perlite
• 1 part coarse sand or grit
• Mineral share 50–70%; dries out within a few days.

Orchids

• 3 parts medium bark
• 1 part perlite or pumice
• Optional: a little sphagnum moss for humidity
• No ordinary soil; roots need air.

Aroids (monstera, philodendron)

• 1 part potting mix
• 1 part orchid bark
• 1 part perlite
• Chunky, airy mix for thick aerial roots.

Vegetables in containers

• 2 parts potting mix
• 1 part compost
• 1 part perlite
• Holds steady moisture; feed regularly through the season.

Mix your own potting soil step by step

Making your own mix is cheaper for larger amounts and lets you tune it to each plant. To work out how much soil your pots need, use our Soil calculator.

1. Pick the recipe: Choose the mix from the table above and decide the total amount you need.
2. Protect yourself: Work outdoors or in a ventilated spot. Lightly mist perlite and dry peat before pouring; the dust is irritating, so a simple dust mask helps.
3. Prepare the base: Break up compressed coir bricks in warm water, or moisten dry peat until it feels like a wrung-out sponge.
4. Measure in parts: Use the same container (a bucket or a pot) for every ingredient so the ratios stay consistent.
5. Mix thoroughly: Combine everything in a tub or on a tarp and turn it over several times until the color is even.
6. Squeeze test: Squeeze a handful. It should hold together briefly and crumble when poked. If water drips out, it is too wet; if it will not hold at all, add a little base.
7. Use or store: Pot up right away, or keep leftovers in a closed bag in a cool, dark place.

Soil fatigue and when to renew it

Potting mix wears out. Organic parts break down and compact, air spaces shrink, salts from fertilizer and tap water build up and nutrients run out. Signs that the soil is tired:

• Water runs straight through, or sits on the surface for a long time.
• A white crust forms on the soil or pot rim.
• The soil has sunk well below the rim and feels hard.
• Growth slows even though light and watering are right.

Replace the mix every 1–2 years (estimated); orchids every 1–2 years as the bark decays. For large pots that are hard to repot, scrape off the top 1–2 in and replace it with fresh mix. Our repotting guide covers the move itself step by step.

Quick checklist before you buy

• The pot has a drainage hole, or you will use it as a cachepot.
• It is only one size larger than the current root ball.
• The material suits the plant: terracotta for dry-lovers, plastic or glazed for moisture-lovers.
• The bag says potting mix, not garden or topsoil.
• You have perlite or pumice on hand to lighten heavy mixes.
• Mixes for succulents, orchids and aroids are chunkier than general houseplant mix.

Frequently asked questions

Plants with different pot and soil needs

MonsteraEcheveriaOrchidHaworthiaRubber PlantSnake PlantTomatoPeace lily