Growli

Container guide

Growing great mullein in a pot

Verdict
Ideal in pots
Pot size
15-20 cm (6-8 in) across
Mature size
Rosette to 60 cm across in year one; flower spike 1–2 m tall in year two.

Compost and drainage

Great Mullein needs sharp drainage, so this matters more in a pot than in the ground. Use a free-draining mix (add perlite, grit or bark to standard compost), always pick a container with drainage holes, and never let it stand in a saucer of water.

Watering great mullein in a pot

Containers dry far faster than open ground, so great mullein in a pot needs checking more often than the general guidance of "Low — once established, rainfall is usually sufficient" — especially in summer, wind, or a heated room. Check the top few centimetres with a finger rather than watering on a fixed day.

Potting on

Pot on when roots show through the drainage holes or growth slows noticeably — usually every 1-2 years for a plant this size. Move up one pot size only; jumping several sizes leaves wet compost the roots cannot reach, and that is what rots them.

More great mullein care

Growing great mullein in containers — FAQ

Can you grow great mullein in a pot?

Great Mullein is well suited to container growing — at about 60 cm mature it is comfortably pot-sized. A container around 15-20 cm (6-8 in) across gives it room without leaving the compost sitting wet, which is the usual mistake when people over-pot a small plant.

What size pot does great mullein need?

Aim for a container 15-20 cm (6-8 in) across. Pot on when roots show through the drainage holes or growth slows noticeably — usually every 1-2 years for a plant this size. Move up one pot size only; jumping several sizes leaves wet compost the roots cannot reach, and that is what rots them.

What compost and drainage does great mullein need in a container?

Great Mullein needs sharp drainage, so this matters more in a pot than in the ground. Use a free-draining mix (add perlite, grit or bark to standard compost), always pick a container with drainage holes, and never let it stand in a saucer of water.

How often should I water great mullein in a pot?

Containers dry far faster than open ground, so great mullein in a pot needs checking more often than the general guidance of "Low — once established, rainfall is usually sufficient" — especially in summer, wind, or a heated room. Check the top few centimetres with a finger rather than watering on a fixed day.