What is the best soil mix for houseplants?

For most houseplants, a good general potting mix with about 30% perlite works well. Aroids like monstera prefer a chunkier mix with orchid bark, succulents want a gritty mix, and ferns and calatheas like a moisture-holding mix with coir.

Can I use garden soil for houseplants?

No. Garden soil compacts in pots, drains poorly and can bring in pests, weed seeds and diseases. Use a bagged potting mix as the base.

What does perlite do in potting soil?

Perlite is expanded volcanic glass. It doesn't hold much water itself, so it creates air pockets that improve drainage and let oxygen reach the roots. That reduces the risk of root rot.

Is potting mix the same as compost?

Not quite. Potting mix (called multi-purpose or houseplant compost in the UK) is a blend designed for containers. Garden compost is decomposed organic matter, which is too rich and dense to use alone in pots but can be a small part of a mix.

How do I measure a soil mix ratio?

By volume, with the same jug, scoop or pot for every ingredient. For example, a 70:30 general mix is 7 scoops of potting soil to 3 scoops of perlite.

Houseplant Soil Mix: 4 DIY Recipes and Ratios That Work

The best houseplant soil mix depends on the plant, but four recipes cover almost everything: a general mix (70% potting soil, 30% perlite) for most houseplants, a chunky aroid mix (40% potting soil, 30% orchid bark, 20% perlite, 10% charcoal) for monstera, philodendron and pothos, a gritty succulent mix (50% cactus soil, 40% pumice or perlite, 10% grit) for succulents, snake plants and ZZ plants, and a moisture-holding mix (60% potting soil, 25% coco coir, 15% perlite) for ferns and calatheas. All ratios are by volume.

Why soil matters so much in pots

A pot is a small, closed space. Water drains to the bottom and stays there in a saturated layer. Roots need both water and air. A dense mix fills every gap with water, the roots run out of oxygen, and they rot. That's why most "overwatering" problems are partly soil problems.

A good houseplant soil mix balances three things:

Water holding: enough to keep roots supplied between waterings.
Air space: enough gaps for oxygen.
Structure: chunks that don't collapse and compact over time.

The four DIY houseplant soil mix recipes

These are common, widely used starting recipes. They're the same four built into our soil mix calculator, which scales them to any volume.

Recipe	Ratio by volume	Best for
General houseplant mix	70% potting soil, 30% perlite	Most foliage plants: spider plant, peace lily, rubber plant, dracaena
Chunky aroid mix	40% potting soil, 30% orchid bark, 20% perlite, 10% horticultural charcoal	Monstera, philodendron, pothos, other aroids
Gritty succulent mix	50% cactus soil, 40% pumice or perlite, 10% coarse sand or grit	Succulents, aloe, haworthia, snake plant, ZZ plant
Moisture-holding mix	60% potting soil, 25% coco coir, 15% perlite	Ferns, calatheas, prayer plants

How much to mix: worked examples

You need	Recipe	Measure out
5 L	Chunky aroid	2 L soil, 1.5 L bark, 1 L perlite, 0.5 L charcoal
10 L	General	7 L soil, 3 L perlite
3 L	Gritty succulent	1.5 L cactus soil, 1.2 L pumice/perlite, 0.3 L grit
4 L	Moisture-holding	2.4 L soil, 1 L coir, 0.6 L perlite

Not sure how many litres? Our repotting pot size calculator works out the volume of a tapered pot. A 19 cm pot that's 14 cm across the base and 17 cm tall holds about 3.7 litres.

Adjusting the ratio for your home

The recipes are starting points. Tweak them to match how you grow:

Low light or a heavy hand with the watering can? Shift towards drainage. Add another 10% perlite or bark and reduce the soil by the same amount. Plants in dim rooms use water slowly, so a faster-draining mix gives you a margin for error.
Bright, warm room or terracotta pots? Shift towards water holding. Add 10% more soil or coir, because the pot and the room already dry things out quickly.
Hanging baskets? They dry fast at the top of a room. A moisture-holding or general mix usually beats a chunky one.
Self-watering pots? Use an airy mix with plenty of perlite. A dense mix in a reservoir pot stays soggy.
Large pots? A bigger volume dries more slowly, so lean towards the airier end of the recipe.

Change one thing at a time and watch how fast the pot dries. If the soil is still damp a week after watering in the growing season, the mix is too dense for that spot.

What each ingredient does

Ingredient	What it is	What it does	Notes
Potting soil / multi-purpose compost	Peat or peat-free base with nutrients	Holds water and nutrients	The base of most mixes. Peat-free options are widely available.
Perlite	Expanded volcanic glass	Adds air, improves drainage	Light, white. Wear a mask when pouring dry.
Pumice	Porous volcanic rock	Like perlite but heavier, doesn't float	Good for succulents
Orchid bark	Chunks of pine or fir bark	Large air pockets, structure	Key to chunky aroid mixes
Coco coir	Coconut husk fibre	Holds moisture, rewets easily	Peat alternative. Rinse if salty.
Horticultural charcoal	Charcoal pieces	Adds structure and air	Benefits beyond structure are debated
Coarse sand or grit	Small stones	Weight and drainage	Use horticultural grit, not fine play sand
Vermiculite	Expanded mineral	Holds water and nutrients	Good in seed mixes, less in chunky ones
Worm castings	Worm compost	Gentle nutrients	Small amounts only

Is peat a problem?

Peat-based mixes hold water well and are cheap, but peat extraction damages peatland habitats, and in the UK, retail sales of peat compost are being phased out. Peat-free mixes based on coir, bark and wood fibre work well for houseplants. They can dry out and rewet differently, so check the soil by feel when you switch.

Houseplant soil mix by plant

Plant	Recommended mix	Guide
Monstera	Chunky aroid	Monstera care guide
Pothos	General or chunky aroid	Pothos care guide
Snake plant	Gritty succulent	Snake plant care
ZZ plant	Gritty succulent or general	ZZ plant care
Peace lily	General or moisture-holding	Peace lily care
Spider plant	General	Spider plant care
Boston fern, calathea	Moisture-holding	Bathroom plants

How to make your own houseplant soil mix

Pick a recipe from the table above.
Choose a measuring container. A jug, scoop or old 1 litre pot. Use the same one for every ingredient.
Lightly moisten the dry ingredients before mixing. Dry peat or coir repels water, and dry perlite is dusty.
Mix in a tub, bucket or on a tarp, turning it over until evenly blended.
Store leftovers in a sealed bag or tub with a few air holes, out of the sun.

Bagged houseplant potting mix

You don't have to mix your own. A good bagged houseplant mix works for most plants. To improve a bag:

Add perlite (about 1 part to 2–3 parts mix) for drainage.
Add orchid bark for aroids.
Add grit or pumice for succulents.

Check the bag: avoid mixes that feel heavy and sticky when wet, or that are full of large woody chunks unless you're potting aroids.

Signs your plant is in the wrong soil

Sign	Likely problem	Fix
Soil stays wet for over a week	Too dense, not enough air	Add perlite or bark at next repot
Water runs straight through, plant always thirsty	Too coarse, or old soil gone hydrophobic	Soak the pot, add some coir
Soil shrinks from the pot wall	Dried-out peat	Bottom-water to rewet
White crust on the surface	Fertilizer or water salts	Flush with plenty of water
Fungus gnats	Surface stays damp	Let the top dry, add grit on top
Soil sinks and compacts	Old mix broken down	Repot in fresh mix

How often to replace houseplant soil

Potting mix breaks down over time and loses its structure. Most houseplants benefit from fresh mix every 1–3 years, usually at repotting. For large plants you don't want to repot, replace the top few centimetres each spring. Our step-by-step guide to how to repot a houseplant explains both.

Fertilizer and fresh mix

Many bagged mixes contain a starter fertilizer that lasts a few weeks to a few months. Wait about 4–6 weeks after repotting before feeding, then use a diluted liquid feed in the growing season. Our fertilizer dilution calculator works out the dose. Homemade mixes with lots of bark, perlite and grit contain few nutrients, so they need regular feeding sooner.

Sources and further reading

Royal Horticultural Society, on growing media, peat-free composts and container growing.
Penn State Extension, on soilless growing media for container plants.
University of Minnesota Extension, on potting mixes for houseplants.

Once your mix is right, the next most important habit is watering properly. See how to water houseplants.