How to Choose the Right Size Plant Pot for Your Plants

Choosing the right size plant pot is one of the most important decisions you can make for your plants — and one of the easiest to get wrong. A pot that is too small restricts root growth, causes the soil to dry out quickly, and leaves your plant competing for nutrients. A pot that is too large holds excess moisture around the roots, which can lead to root rot and slow, stunted growth.

The good news is that getting it right is simple once you know the rules. This guide walks you through everything you need to know about plant pot sizing, from quick rules of thumb to specific recommendations for popular houseplants.

The Golden Rule: Go 2–5cm Wider Than the Current Pot

When repotting a plant, the new pot should be roughly 2 to 5 centimetres wider in diameter than the existing one. That is it. Resist the temptation to jump to a much larger pot — more soil does not mean faster growth. In fact, too much excess soil around a small root ball stays wet for too long, starving the roots of oxygen and creating the perfect conditions for fungal disease.

For most houseplants, a step up of one size is ideal. If your plant is currently in a 14cm pot, move it to a 17 or 19cm pot. If it is in a 19cm pot, go to a 22 or 24cm pot.

How to Tell When Your Plant Needs a Bigger Pot

Plants do not need repotting on a schedule. Instead, watch for these signs that tell you your plant has outgrown its current home:

• Roots growing out of the drainage holes — the clearest sign. If you can see roots poking through the bottom, the plant has run out of room.
• The plant dries out within a day or two of watering — when roots fill most of the pot, there is very little soil left to hold moisture.
• Growth has slowed or stopped — even during spring and summer, a root-bound plant struggles to put out new leaves.
• The plant is visibly top-heavy — if your plant topples over easily, the root system is out of proportion with the pot.
• Roots circling tightly at the surface — when you lift the plant out and see a dense mat of circling roots, it is time.

If your plant is happy, stable, and growing well, leave it where it is. Unnecessary repotting can stress a plant just as much as being root-bound.

Plant Pot Size Guide: Quick Reference Chart

Use this chart as a starting point. The right size depends on your specific plant, but these are reliable general guidelines for the most popular houseplants:

Tip: If you are unsure between two sizes, go with the smaller option. It is always safer to size up gradually than to risk overwatering in a pot that is too large.

Does Pot Shape Matter?

Yes, and more than most people realise. The shape of a plant pot affects drainage, root growth, and how the plant sits in your space.

Tall, narrow pots are ideal for plants with deep root systems like snake plants, dracaenas, and fiddle leaf figs. The extra depth gives roots room to grow downwards, which promotes stability. Tall pots also work brilliantly in narrow spaces like hallways and beside doorways. [Browse our Tall Plant Pots →]

Low, wide pots suit plants with shallow, spreading root systems like succulents, herbs, and many ferns. They also look stunning on coffee tables and windowsills where a tall pot would block light. [Browse our Low Profile Planters →]

Square pots maximise soil volume compared to round pots of the same width. The corners provide extra growing space, making them a smart choice when you want to give your plant the most room without going up a full size. They also sit neatly against walls and in corners. 

Do You Need Drainage? The Case for Pots with Inserts

Drainage is non-negotiable for healthy plants. Without it, water collects at the bottom of the pot, the soil stays waterlogged, and roots begin to rot. It is the single most common reason houseplants die.

There are two ways to handle drainage:

Option 1 — A pot with drainage holes. Water runs straight through, excess drains into a saucer. Simple and effective, but you need to protect the surface underneath.

Option 2 — A decorative pot with a removable insert (cache pot). This is the most versatile approach. Keep your plant in its nursery pot or a liner with drainage holes, then drop it into the decorative outer pot. When you water, simply lift out the insert, let it drain in the sink, and pop it back. No mess, no saucers, no water marks on your furniture.

All Dalugo planters include a removable inner insert, giving you the flexibility to use them either way. Browse our collection here

Common Sizing Mistakes to Avoid

• Going too big too fast: Jumping from a 14cm pot to a 30cm pot seems logical (“more room to grow!”) but the excess soil stays wet, roots cannot access it, and the plant often declines. Stick to the 2–5cm rule.
• Ignoring depth: A wide but shallow pot will not suit a plant with a deep taproot. Similarly, a tall narrow pot is wasted on a shallow-rooted succulent. Match the pot shape to the root type.
• Repotting at the wrong time: Spring and early summer are the best times to repot. Avoid repotting in winter when most plants are dormant — they will not grow into the new soil and are more vulnerable to overwatering.
• Forgetting about the material: Terracotta dries out faster (good for succulents), while plastic and glossy pots retain moisture longer (better for tropical plants that like humidity). Factor this into your sizing decision.

A Quick Decision Checklist

Before you buy your next plant pot, run through these five questions:

• What is the diameter of the current pot? Measure across the top. Your new pot should be 2–5cm wider.
• Does the plant have deep or shallow roots? Deep roots need a tall pot. Shallow roots suit a low, wide pot.
• Where will the pot sit? Windowsill? Shelf? Floor? Make sure the pot fits the space physically and visually.
• Do you need drainage? Almost always yes. A pot with a removable insert gives you the most flexibility.
• Indoor, outdoor, or both? If the pot will live outside, choose one rated as UV and frost resistant.
  

Find Your Perfect Size at Dalugo

Every Dalugo planter comes in multiple sizes so you can find the perfect fit for your plant. Our square plant pots start from a compact 19cm up to a generous 40cm, and our tall planters range from 27cm to over 60cm. All come with removable inserts, are rated for indoor and outdoor use, and ship free across the UK.

Shop All Plant Pots