Repotting guide

When & how to repot Flame nasturtium (Tropaeolum speciosum)

Also called Flame nasturtium, Flame creeper, Scottish flame flower.

More about flame nasturtium

About Flame nasturtium

Tropaeolum speciosum · also called Flame nasturtium, Flame creeper · flowering

Flame nasturtium is a tuberous, herbaceous perennial climber native to the cool forests of Chile. Its brilliant scarlet flowers appear from midsummer to early autumn, followed by striking blue berries held in red calyces. It thrives in cool, moist gardens with its roots in shade and stems climbing into sun — a favourite for draping over dark evergreen hedges. RHS Award of Garden Merit holder.

Mature size: 2.5–3 m tall; spread 60–90 cm

Watch for — Failure to establish or return after winter: Most common in alkaline, dry, or south-facing warm soils; the tuber desiccates in summer heat — cool, acid, humus-rich soil with the root zone in shade is non-negotiable.

How to tell flame nasturtium needs repotting

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

Flowering has tailed off year on year and the clump has become congested and overcrowded.
Lots of leaf and few flowers — a classic sign that flame nasturtium bulbs or tubers need lifting and dividing.
Bulbs visibly bursting the pot or pushing each other to the surface.
It is the natural dormancy window (foliage yellowed and died back) — the only safe time to lift and split.

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 flame nasturtium

Lift and divide every 3–4 years once clumps congest. Rather than a true repot, flame nasturtium is lifted and divided once the clump congests and flowering drops off. Slender herbaceous perennial climber with tuberous roots; dies back to ground each winter.

What size pot to step flame nasturtium up to

Pot size matters less than depth and spacing here. When you replant flame nasturtium, set the bulbs or tubers at the correct depth (a rough guide: two to three times their own height of soil over the top) and space them so they are not touching. A wide, shallow pot suits a clump better than a tall narrow one.

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 flame nasturtium

The only safe window is dormancy: wait until the foliage has yellowed and died back naturally, lift and divide then, and replant before or at the start of the next growing season. Disturbing flame nasturtium in full growth or flower sets it back badly.

Step-by-step: repotting flame nasturtium

Wait for dormancy. Let flame nasturtium foliage yellow and die back completely. Lifting while it is in growth wastes the energy it is storing for next year.
Lift carefully. Loosen the soil well away from the bulbs/tubers with a fork and ease the whole clump out without spearing them.
Separate the offsets. Gently pull the clump apart into individual bulbs or tubers. Keep only firm, healthy, blemish-free ones.
Replant at the right depth. Reset them in fresh moist, humus-rich, acid to neutral soil at the correct depth and spacing — not touching — so each has room to bulk up.
Water in and rest. Water once to settle them, then keep on the dry side until growth resumes. Do not feed until leaves are actively growing.

Aftercare

After replanting flame nasturtium, keep the soil barely moist — not wet — until shoots appear; bulbs and tubers rot in cold, saturated soil. Once leaves are growing strongly, resume normal watering. Hold off feeding until the plant is in active growth again.

The right soil mix for flame nasturtium

Flame nasturtium wants moist, humus-rich, acid to neutral soil. Prefers a cool, leafy, woodland-type soil with pH 5.5–6.5. Incorporate plenty of leaf mould or garden compost at planting. Dry, sandy, or chalky alkaline soils are unsuitable — the plant struggles and rarely returns after winter. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting flame nasturtium — frequently asked questions

How often should you repot flame nasturtium?

Lift and divide every 3–4 years once clumps congest for flame nasturtium. Flame nasturtium is lifted and divided, not "repotted". Every 3–4 years, once the foliage has died back and it is dormant, lift the clump, separate the offsets, and replant at the correct depth in moist, humus-rich, acid to neutral soil. Crowding, not pot size, is what reduces flowering over time.

What size pot does flame nasturtium need?

When is the best time of year to repot flame nasturtium?

Do you "repot" flame nasturtium, or lift and divide it?

You lift and divide it. Flame nasturtium grows from bulbs or tubers, so instead of repotting you wait for dormancy, lift the congested clump, separate the healthy offsets, and replant them at the right depth and spacing. Doing this every 3–4 years restores flowering.

Should you fertilise flame nasturtium after repotting?

Hold off feeding flame nasturtium until it is in active growth again. Fresh soil already carries enough nutrients to get it re-established, and feeding disturbed roots too soon does more harm than good.