Repotting guide

When & how to repot African marigold (Tagetes erecta)

Also called African marigold, Aztec marigold, American marigold, big marigold.

More about african marigold

About African marigold

Tagetes erecta · also called African marigold, Aztec marigold · flowering

A tall, upright annual from Mexico bearing large, pompom-like flower heads in bold shades of yellow, gold, and orange from summer to first frost. Extremely heat-tolerant and drought-resilient once established, it thrives in full sun with minimal care. Widely used in borders and as a companion plant for its nematode-suppressing root exudates.

Mature size: 30–90 cm tall (cultivar-dependent); 30–60 cm spread

How to tell african marigold needs repotting

Repotting on a calendar is less reliable than reading the plant. For african marigold, watch for these signs:

Roots circling the bottom of the module or pot, or poking out of the drainage holes.
The seedling dries out within a day and growth has visibly stalled.
Roots are white and matted in a tight spiral when you tip the plant out.
It has outgrown its current container for the stage of the season — pot african marigold on before it becomes hard root-bound.

For the underlying biology of a pot-bound root system and why it stalls a plant, see our guide to spotting and fixing a root-bound plant.

How often to repot african marigold

Pot on seedlings as they grow; not a perennial repot. African marigoldis grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Upright, bushy annual.

What size pot to step african marigold up to

Pot african marigold on gradually — a seedling jumped straight into a huge pot sits in cold, wet, airless soil and stalls. Step up one or two sizes at a time as the roots fill each container, finishing in a large final pot or the ground. The aim is roots that never circle and never check.

Not sure of the exact diameter? Our pot size calculator takes the current pot and root spread and tells you the right next size — it deliberately recommends a single step up, never a big jump.

The best time of year to repot african marigold

Pot african marigold on through the active growing season, whenever roots fill the current container — there is no single date, just "before it becomes root-bound". Avoid potting on during a cold snap.

Step-by-step: repotting african marigold

Pot on before it is root-bound. Check african marigold regularly; move it up as soon as roots reach the edge of the cell or pot, not after they have circled.
Step up one or two sizes. Choose the next container up — not a giant one. Cold, wet, unused soil around a small root system stalls seedlings.
Knock it out gently. Support the stem, tip the pot, and ease the rootball out without breaking it. A little teasing of circled roots at the base is fine.
Pot into rich mix. Set it into fresh moderately fertile, well-draining loam or sandy loam at the same depth (tomatoes are the exception — they can go deeper to root along the stem).
Water in and grow on. Water well, keep it in good light, and resume feeding once it is established and growing again.

Aftercare

Water african marigold in well and keep it in bright light; a freshly potted-on seedling can wilt for a day while roots settle, so do not overcompensate by drowning it. Do not fertilise for about 1 week — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for african marigold

African marigold wants moderately fertile, well-draining loam or sandy loam. Tolerates a wide range of soils including clay, but must drain freely. Excessively rich soil promotes lush foliage at the expense of flowers. Soil pH 6.0–7.5. Work in compost before planting. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting african marigold — frequently asked questions

How often should you repot african marigold?

Pot on seedlings as they grow; not a perennial repot for african marigold. African marigold is a seasonal crop, so you pot it on as a growing plant rather than repotting a perennial. Step seedlings up gradually into moderately fertile, well-draining loam or sandy loam so the roots never circle the cell, ending in a large final container. A root-bound transplant stalls and never fully recovers.

What size pot does african marigold need?

When is the best time of year to repot african marigold?

Can you put african marigold straight into a much bigger pot?

No. Even a fast-growing african marigold should only go up one pot size at a time. A vastly oversized pot holds a reservoir of wet soil the roots cannot reach, which stays cold and soggy and rots the roots — the opposite of what you wanted.

Should you fertilise african marigold after repotting?

Not immediately. Wait about 1 week after repotting african marigold. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.