Repotting guide

When & how to repot Million Bells 'Superbells' (Calibrachoa 'Superbells')

Also called Million bells, Calibrachoa, Trailing petunia.

More about million bells 'superbells'

About Million Bells 'Superbells'

Calibrachoa 'Superbells' · also called Million bells, Calibrachoa · flowering

Superbells calibrachoa pack hundreds of small petunia-like blooms onto trailing stems, flowering nonstop with no deadheading. They thrive in baskets and containers but resent wet feet and high pH, which trigger yellowing. Give them sun, sharp drainage, and steady feeding. ASPCA-listed as non-toxic to cats and dogs.

Mature size: 15-30 cm tall, trailing 30-60 cm

Watch for — Root rot from overwatering: The most common killer — soggy mix causes wilting, browning, and collapse. Use fast-draining soil and let the surface dry between waterings.

How to tell million bells 'superbells' needs repotting

Repotting on a calendar is less reliable than reading the plant. For million bells 'superbells', 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 million bells 'superbells' 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 million bells 'superbells'

Pot on seedlings as they grow; not a perennial repot. Million Bells 'Superbells'is grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Trailing, mounding tender perennial grown as an annual; produces dense cascades of small, bell-shaped blooms that spill over basket and container edges..

What size pot to step million bells 'superbells' up to

Pot million bells 'superbells' 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 million bells 'superbells'

Pot million bells 'superbells' 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 million bells 'superbells'

Pot on before it is root-bound. Check million bells 'superbells' 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 light, fast-draining, slightly acidic potting mix 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 million bells 'superbells' 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 million bells 'superbells'

Million Bells 'Superbells' wants light, fast-draining, slightly acidic potting mix. Sharp drainage is critical. Use a quality container mix; calibrachoa prefer acidic soil (pH 5.5-6.5) and develop iron-deficiency yellowing in alkaline media or alkaline water. Add an acidic or iron-supplemented feed if leaves pale between the veins. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting million bells 'superbells' — frequently asked questions

How often should you repot million bells 'superbells'?

Pot on seedlings as they grow; not a perennial repot for million bells 'superbells'. Million Bells 'Superbells' is a seasonal crop, so you pot it on as a growing plant rather than repotting a perennial. Step seedlings up gradually into light, fast-draining, slightly acidic potting mix 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 million bells 'superbells' need?

When is the best time of year to repot million bells 'superbells'?

Can you put million bells 'superbells' straight into a much bigger pot?

No. Even a fast-growing million bells 'superbells' 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 million bells 'superbells' after repotting?

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