How do I plant a pot so it does not dry out?

Most container plants struggle because of the pot rather than the plant. Volume of compost is what buys you time between waterings.

What you'll need

• A pot with drainage holes, larger than seems necessary
• Peat-free or loam-based compost to suit the plant
• Water-retaining granules or mulch, optionally

Step by step

1. Choose the biggest pot you reasonably can.Compost volume is the single biggest factor in how often you water. A small pot in July may need water twice a day; the same plant in a large one may need it every three.
2. Check the drainage holes are adequate.Several holes, not one small one. A pot that cannot drain drowns roots, and drowned roots produce exactly the wilting that looks like drought.
3. Pick the material deliberately.Terracotta is porous and dries fast, which suits Mediterranean herbs. Glazed and plastic hold moisture far better. Metal heats up in sun and cooks roots on a south-facing wall.
4. Match the compost to the plant's life.Multipurpose for a season of bedding, loam-based John Innes for anything staying more than a year. Loam holds water and nutrients far better over time.
5. Skip the crocks.Stones or broken pots in the base do not improve drainage — they reduce the compost volume and create a perched water table. A piece of mesh over the hole is enough to stop compost washing out.
6. Wet the compost before planting.Dry peat-free compost is hydrophobic and very hard to wet once it is in the pot. Mix water in beforehand until it is evenly damp.
7. Leave a watering gap.Three to four centimetres between the compost surface and the rim. Without it, water runs straight over the edge and never soaks in. This is the most commonly skipped step.
8. Plant at the right depth.Same level as it was in its previous pot. Burying the stem causes rot; planting proud leaves the rootball exposed and it dries out from the side.
9. Tease out the roots.If the plant is pot-bound, loosen the outer roots or cut through them. Roots left circling continue to circle and never grow into the new compost.
10. Firm gently, do not compress.Enough to remove air pockets, not enough to compact. Compacted compost holds water without holding air, which suffocates roots.
11. Consider water-retaining granules.Genuinely effective in containers, mixed through at planting. They swell and release moisture slowly. Follow the dose — too many and the compost becomes a sodden gel.
12. Mulch the surface.Gravel, bark or slate chippings. It reduces evaporation substantially, suppresses weeds and stops heavy watering splashing compost out.
13. Group pots together.They shade each other and raise local humidity, which noticeably reduces water loss. A pot standing alone on hot paving is the worst case.
14. Raise pots off hot surfaces.Pot feet or a slab. It improves drainage and stops the base absorbing heat from paving, which dries the compost from below.
15. Water thoroughly, not often.Until it runs from the drainage holes. A light daily sprinkle wets only the top and encourages shallow roots that dry out even faster.
16. Check by weight.Lift the pot or tip it. Weight is far more reliable than the surface, particularly with peat-free compost that looks dry on top while wet below.

Tips

• Leave a 3 to 4cm gap below the rim. Without it, water runs off rather than in.
• Bigger pot, less watering. Compost volume is what buys you time.
• Crocks in the base do not help drainage — they just reduce the compost you could have had.

Common mistakes

• Filling the pot to the rim — There is nowhere for water to sit while it soaks in, so it runs over the edge and the rootball stays dry however long you stand there with a can.
• Watering little and often — It wets only the top few centimetres, so roots stay shallow and the plant becomes more vulnerable to drying out, not less. Water thoroughly and less frequently.

If it doesn't work

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