A houseplant lives or dies by its container. In the wild, a monstera deliciosa climbs a tree with its roots in a deep layer of loose, humus-rich debris; in your home, the same plant lives in a litre or two of potting mix in a plastic pot, and everything it needs — water, air, nutrients — has to come through that small volume. The pot and the mix are therefore not decoration; they are the plant's whole world, and getting them right is the difference between a plant that thrives and one that slowly declines.
This guide covers choosing pots, making and choosing mixes, drainage, and arranging several plants together in a way that looks good and keeps them all healthy. It covers the practical details — pot size, drainage holes, cache pots, and self-watering pots — and the mistakes that cause most container problems. Your local extension service can advise on mixes and materials available in your area.
Choosing a pot: size, material and drainage
The first rule is that the pot must have a drainage hole. A pot without drainage holds water at the bottom, the roots sit in it, and they rot — there is no way around this, and a layer of gravel at the bottom does not help, because the water still has nowhere to go. The second rule is size: choose a pot only one size larger than the one the plant is in, about 2–5 centimetres wider. A pot that is far too large holds a volume of wet mix that the small root system cannot dry out, and the plant rots. Terracotta pots are porous, so they dry out faster and suit plants that like to dry between waterings, such as the snake plant Laurentii and the ZZ raven; plastic and glazed ceramic pots hold moisture longer and suit plants that like steady moisture, such as the calathea medallion and the boston fern. A decorative outer pot, or cache pot, without drainage is fine, provided you take the plant out to water it and let it drain before putting it back. The repotting calculator can help you judge when a plant has outgrown its pot.
Potting mixes: one mix does not fit all
Houseplants do not all want the same mix. A general houseplant mix — peat or coir, bark, and perlite — suits most plants, including the golden pothos, the philodendron Brasil, and the rubber plant. Plants that climb or grow on trees, such as the monstera deliciosa and the monstera adansonii, want a chunkier, airier mix with plenty of orchid bark and perlite, so air reaches the roots. Succulents and cacti, such as the aloe vera, want a very free-draining mix with extra perlite or grit, and they will rot in a standard mix that stays wet. African violets want a light, airy mix and are easily damaged by a heavy, wet one. Never use garden soil in a container — it compacts, drains badly, and may carry pests and disease. Buy a good mix, or make your own from coir, bark, and perlite in roughly equal parts for aroids such as monstera and philodendron, and add extra perlite for succulents. Replace the mix when you repot, since old mix breaks down, compacts, and loses its drainage.
Arranging plants together
Several plants in one container, or several containers grouped together, look better and grow better than a single plant alone — but only if the plants share the same needs. Group plants with similar light and water requirements: a monstera deliciosa, a philodendron Brasil, and a golden pothos all want bright indirect light and watering when the top soil dries, so they group well. Do not put a snake plant Laurentii, which wants to dry out completely, in the same container as a calathea medallion, which wants steady moisture — one of them will always be unhappy. In a shared container, give each plant room to grow, and expect to separate them in a year or two as they grow. Grouping separate pots together raises the humidity around the plants, which tropical plants such as the calathea medallion and the boston fern appreciate, and it looks better than a row of single pots spaced apart. Put the tallest plant at the back, the trailing plants at the front, and leave a gap for air to move between the pots.
Self-watering pots and other systems
Self-watering pots have a reservoir at the bottom and a wick that draws water up into the mix, and they can be useful for plants that like steady moisture, such as the peace lily family and the calathea medallion — but they are dangerous for plants that like to dry out, such as the snake plant and the ZZ raven, which will rot in a constantly moist mix. If you use a self-watering pot, let the reservoir run dry for a few days between refills, and check the soil regularly — the system is not a substitute for looking at the plant. Hanging planters suit trailing plants such as the golden pothos and the Njoy pothos, but they dry out faster than pots on a shelf, because warm air rises and the small volume of mix dries quickly, so check them more often. Wall-mounted planters and terrariums look striking but are hard to water evenly and easy to overwater, so keep them for plants that tolerate the conditions and check them weekly.
Watering and feeding in containers
Water a container plant thoroughly, until water runs out of the drainage hole, and then empty the saucer — a plant standing in water will rot. Watering a little and often is worse than watering thoroughly and rarely, because it wets only the surface and leaves the lower roots dry while the surface stays damp enough for fungus gnats. Feed container plants lightly while they are growing, in spring and summer, with a half-strength liquid fertilizer once a month, since the small volume of mix has no nutrients to fall back on. Our houseplants fertilizing guide covers the details. Flush the mix every few months by watering thoroughly so water runs through the pot for a minute, which washes out the accumulated fertilizer salts that cause brown leaf tips. If the mix has shrunk away from the sides of the pot and water runs straight down the gap, the mix is exhausted and the plant needs repotting into fresh mix.
When to repot, and how
Repot when the roots are coming out of the drainage hole, when the plant dries out within a day or two of watering, or when the growth has slowed for no other reason — usually every one to three years, depending on the plant. The monstera deliciosa needs repotting every two to three years; the snake plant Laurentii can go far longer. Water the plant the day before, tip it out gently, tease out the circling roots at the base, and put it in a pot one size larger with fresh mix, at the same depth it was growing. Water it in well and keep it out of direct sun for a few days. Do not repot a plant that is stressed, dormant in winter, or newly bought — let it settle first. And do not repot into a pot that is far too large: the extra wet mix will rot the roots. If you are unsure about a diagnosis, a product, or a local rule, check your local extension service — its advice is tailored to your soil, climate, and the pests and diseases active in your area.
Frequently asked questions
Do houseplant pots need drainage holes?
Yes. A pot without drainage holds water at the bottom and the roots rot. A layer of gravel does not substitute for a hole. Use a cache pot outside a drained pot instead.
What potting mix should I use for monstera?
A chunky, airy mix with orchid bark and perlite, so air reaches the roots. A standard dense mix stays too wet for aroids such as monstera and philodendron.
Can I use garden soil for houseplants?
No. Garden soil compacts in a pot, drains badly, and may carry pests and disease. Use a houseplant potting mix.
How do I know when to repot?
When roots come out of the drainage hole, when the plant dries out within a day or two of watering, or when growth has slowed for no other reason — usually every one to three years.
Are self-watering pots good for houseplants?
They suit plants that like steady moisture, such as calathea, but they will rot plants that like to dry out, such as snake plants and ZZ plants. Let the reservoir run dry between refills.