Repotting guide

When & how to repot Spotted Dead Nettle (Lamium maculatum)

Also called Spotted Dead Nettle, Spotted Henbit, Purple Dragon Dead Nettle.

More about spotted dead nettle

About Spotted Dead Nettle

Lamium maculatum · also called Spotted Dead Nettle, Spotted Henbit · flowering

A fast-spreading, shade-tolerant groundcover perennial with silver-marked leaves and two-lipped pink, purple, or white flowers from spring through summer. Unlike true nettles, it does not sting. Numerous cultivars offer varied leaf and flower colours. Excellent for brightening shaded areas, edging paths, or spilling over retaining walls. Hardy to zone 3.

Mature size: 15–25 cm tall; spreads aggressively — individual plants can cover 60–120 cm or more in a single season

Watch for — Downy mildew and fungal leaf spots: White downy patches or brown leaf spots appear in cool, wet, or humid and stagnant conditions. Improve air circulation by thinning dense patches; avoid overhead watering. Remove affected foliage. Severe cases can be treated with copper-based fungicide, though good cultural practice usually suffices.

How to tell spotted dead nettle needs repotting

Repotting on a calendar is less reliable than reading the plant. For spotted dead nettle, watch for these signs:

Roots spiralling thickly out of the drainage holes or pushing the whole plant up out of the pot.
The pot is so packed that water runs straight through in seconds and barely wets the soil.
It has split a plastic pot, or the rootball is a solid mass with almost no soil left when you slide it out.
Growth and (for spotted dead nettle) flowering have clearly stalled despite good light and feeding — but remember this plant likes being snug, so a little crowding alone is not a reason to repot.

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 spotted dead nettle

Only every 2–4 years, when genuinely crowded. Spotted Dead Nettle is one of the plants that genuinely prefers a snug pot — it grows and flowers better with its roots a little restricted, so resist the urge to repot it on schedule. Low-growing, mat-forming, rhizomatous herbaceous to semi-evergreen perennial; spreads rapidly by horizontal stolons rooting at nodes.

What size pot to step spotted dead nettle up to

Go up only one pot size — roughly 2–3 cm (about an inch) wider in diameter, no more. Spotted Dead Nettle positively prefers a snug pot: it flowers and grows better when the roots are a little restricted. The single biggest repotting mistake here is over-potting — dropping spotted dead nettle into a pot two or three sizes up. All that surplus soil holds water the small root system cannot use, stays cold and wet, and rots the roots within weeks. When in doubt, choose the smaller pot.

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 spotted dead nettle

Early spring, just as new growth restarts, is the ideal window for spotted dead nettle. The plant is moving into its strongest growth phase and re-roots into fresh soil quickly. Avoid repotting in winter dormancy or, for flowering plants, while it is in bud or bloom — recovery is slowest then and you risk dropping the flowers.

Step-by-step: repotting spotted dead nettle

Confirm it actually needs it. Slide spotted dead nettle out and check the roots. Only continue if it is genuinely packed — this plant prefers a snug pot, so if there is still soil and room, put it straight back.
Pick a pot only one size up. Choose a pot just 2–3 cm wider with good drainage. Resist anything bigger; over-potting is the main killer here.
Ease it out gently. Water lightly the day before, then tip spotted dead nettle out, supporting the base. Tease the outer roots free only enough to stop them circling.
Repot at the same depth. Add a layer of fresh moist, well-draining loam or loam-sand mix; adaptable to most average garden soils, set the plant so the soil line sits exactly where it did before, and backfill around the sides, firming lightly.
Settle it in. Water once to settle the soil, then let it sit. Hold off on more water until the top of the soil dries — fresh soil around a small root system stays wet for a while.

Aftercare

Because the new soil holds more water than the old crammed rootball did, ease right back on watering — let the top of the soil dry before you water spotted dead nettle again, or you will rot the roots in the very pot you just moved it to. Keep it out of harsh direct sun for a fortnight. Do not fertilise for about 4 weeks — fresh mix already carries nutrients and feeding freshly disturbed roots scorches them.

The right soil mix for spotted dead nettle

Spotted Dead Nettle wants moist, well-draining loam or loam-sand mix; adaptable to most average garden soils. Accepts a wide pH range (5.5–7.5) and tolerates both clay-heavy and sandy soils if drainage is adequate. Enriching with compost improves performance in very poor soils. Avoid dense, compacted clay without amendment. In containers, use standard multipurpose compost with 15–20% perlite. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting spotted dead nettle — frequently asked questions

How often should you repot spotted dead nettle?

Only every 2–4 years, when genuinely crowded for spotted dead nettle. Only repot spotted dead nettle every 2–4 years, and only when it is genuinely root-bound — it flowers and grows best slightly crowded. Step up just one pot size in spring using moist, well-draining loam or loam-sand mix; adaptable to most average garden soils. The key mistake is over-potting: a too-big pot stays wet and rots the roots.

What size pot does spotted dead nettle need?

When is the best time of year to repot spotted dead nettle?

Does spotted dead nettle like to be root-bound?

Yes — spotted dead nettle genuinely flowers and grows best when slightly pot-bound, so do not rush to repot it. The mistake to avoid is over-potting into a much larger pot: the excess soil stays wet, the roots cannot use it, and the plant rots. Only repot every few years and only one snug size up.

Should you fertilise spotted dead nettle after repotting?

Not immediately. Wait about 4 weeks after repotting spotted dead nettle. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.