Repotting guide

When & how to repot Ipomoea lobata (Ipomoea lobata)

Also called Spanish flag, firecracker vine, exotic love vine.

More about ipomoea lobata

About Ipomoea lobata

Ipomoea lobata · also called Spanish flag, firecracker vine · flowering

Spanish flag is a striking annual climber from Mexico bearing one-sided spikes of tubular flowers that open scarlet and age through orange and yellow to cream, giving a multicoloured 'flag' effect. Vigorous and fast from seed, it twines up supports with three-lobed leaves and flowers from midsummer to frost, attracting bees, butterflies, and hummingbirds.

Mature size: 2-5 m of vining growth in a single season, given a tall support.

How to tell ipomoea lobata needs repotting

Repotting on a calendar is less reliable than reading the plant. For ipomoea lobata, 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 ipomoea lobata 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 ipomoea lobata

Pot on seedlings as they grow; not a perennial repot. Ipomoea lobatais grown for one season, so the question is really “how often to pot on” — keep moving it up before the roots circle. Vigorous twining herbaceous annual climber; produces dense, leafy cover and abundant one-sided racemes of flowers from midsummer until the first frost..

What size pot to step ipomoea lobata up to

Pot ipomoea lobata 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 ipomoea lobata

Pot ipomoea lobata 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 ipomoea lobata

Pot on before it is root-bound. Check ipomoea lobata 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-drained soil 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 ipomoea lobata 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 ipomoea lobata

Ipomoea lobata wants moderately fertile, well-drained soil. Does best in fertile but free-draining soil with steady moisture; unlike some morning glories it tolerates and even appreciates a richer soil. Neutral pH is ideal. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting ipomoea lobata — frequently asked questions

How often should you repot ipomoea lobata?

Pot on seedlings as they grow; not a perennial repot for ipomoea lobata. Ipomoea lobata 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-drained soil 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 ipomoea lobata need?

When is the best time of year to repot ipomoea lobata?

Can you put ipomoea lobata straight into a much bigger pot?

No. Even a fast-growing ipomoea lobata 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 ipomoea lobata after repotting?

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