Growing Coneflower in a pot
For balcony, patio or terrace — Echinacea purpurea
coneflower grows well in a pot of at least Ø 30 cm (21 L capacity), in a position with full sun. Watering: 1-2x per week in summer, only when dry in winter.

Which pot?
Ø 30 cm
~ 21 L potting soil
Give the plant room with a pot slightly wider than the current rootball, with matching depth.
Watering
1-2x per week
only when dry
Always use a pot with drainage holes. Water dries out faster in pots — or the plant drowns. Check weekly with your finger: only water when the top 2 cm of soil is dry.
Pot care
Once established, coneflowers are exceptionally low-maintenance and cope well with neglect. Water only during prolonged dry spells in summer, giving plants a thorough soak every ten to fourteen days rather than frequent light sprinkles. Overwatering or poorly drained soil is far more likely to cause problems than drought, leading to root rot and weak, floppy growth. Feed sparingly. In April, scatter a handful of general-purpose granular fertiliser such as blood, fish and bone or Growmore around each plant and lightly fork it into the soil surface. Avoid high-nitrogen feeds, which produce lush foliage at the expense of flowers and make plants more prone to mildew. One spring feed is sufficient for the entire season—coneflowers grown in rich soil may not need feeding at all. Coneflowers are fully hardy throughout temperate Europe (zone 3a–9b) and need no winter protection. Leave the seed heads standing through autumn and winter for the birds, then cut back in March. Mulch lightly in late autumn if desired, but it's not essential. The main pest to watch for is the coneflower leaf miner, a small fly whose larvae tunnel through leaves, leaving pale, winding trails. Remove and destroy affected foliage promptly. Powdery mildew can appear in late summer, especially in dry conditions or crowded plantings—improve air circulation and avoid overhead watering. Slugs occasionally nibble young spring growth; use your preferred control method if damage is severe. Otherwise, coneflowers are remarkably trouble-free and will reward you with months of nectar-rich flowers and year-round structure.
Pot-specific tip: add slow-release fertiliser pellets in March — potting soil exhausts much faster than open ground.