Repotting guide

When & how to repot Pelargonium x domesticum 'Lavender Grand Slam' (Pelargonium x domesticum 'Lavender Grand Slam')

Also called Lavender Grand Slam pelargonium, Regal pelargonium Lavender Grand Slam.

More about pelargonium x domesticum 'lavender grand slam'

About Pelargonium x domesticum 'Lavender Grand Slam'

Pelargonium x domesticum 'Lavender Grand Slam' · also called Lavender Grand Slam pelargonium, Regal pelargonium Lavender Grand Slam · flowering

'Lavender Grand Slam' is a free-flowering regal pelargonium with large lavender-mauve ruffled blooms feathered and blotched in deeper purple, carried in generous trusses. More floriferous than many regals, it puts on a long spring-to-summer show on upright, bushy plants with crinkled, slightly sticky leaves. It likes cool nights and bright filtered light, grown as a tender perennial under glass or on a patio.

Mature size: 30-45 cm tall and wide.

How to tell pelargonium x domesticum 'lavender grand slam' needs repotting

Repotting on a calendar is less reliable than reading the plant. For pelargonium x domesticum 'lavender grand slam', 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 pelargonium x domesticum 'lavender grand slam') 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 pelargonium x domesticum 'lavender grand slam'

Only every 2–4 years, when genuinely crowded. Pelargonium x domesticum 'Lavender Grand Slam' 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. Upright, bushy evergreen perennial with stiff, serrated, slightly sticky leaves and abundant ruffled flower trusses..

What size pot to step pelargonium x domesticum 'lavender grand slam' up to

Go up only one pot size — roughly 2–3 cm (about an inch) wider in diameter, no more. Pelargonium x domesticum 'Lavender Grand Slam' 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 pelargonium x domesticum 'lavender grand slam' 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 pelargonium x domesticum 'lavender grand slam'

Early spring, just as new growth restarts, is the ideal window for pelargonium x domesticum 'lavender grand slam'. 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 pelargonium x domesticum 'lavender grand slam'

Confirm it actually needs it. Slide pelargonium x domesticum 'lavender grand slam' 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 pelargonium x domesticum 'lavender grand slam' 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 free-draining loam-based potting mix, 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 pelargonium x domesticum 'lavender grand slam' 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 pelargonium x domesticum 'lavender grand slam'

Pelargonium x domesticum 'Lavender Grand Slam' wants free-draining loam-based potting mix. John Innes No. 2 plus grit gives drainage and stability. Avoid water-retentive composts that bring on black-leg. Neutral to slightly alkaline pH is preferred. Always use fresh mix when you repot — reusing old, broken-down soil reintroduces the compaction and poor drainage you are repotting to fix.

Repotting pelargonium x domesticum 'lavender grand slam' — frequently asked questions

How often should you repot pelargonium x domesticum 'lavender grand slam'?

Only every 2–4 years, when genuinely crowded for pelargonium x domesticum 'lavender grand slam'. Only repot pelargonium x domesticum 'lavender grand slam' 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 free-draining loam-based potting mix. The key mistake is over-potting: a too-big pot stays wet and rots the roots.

What size pot does pelargonium x domesticum 'lavender grand slam' need?

When is the best time of year to repot pelargonium x domesticum 'lavender grand slam'?

Does pelargonium x domesticum 'lavender grand slam' like to be root-bound?

Yes — pelargonium x domesticum 'lavender grand slam' 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 pelargonium x domesticum 'lavender grand slam' after repotting?

Not immediately. Wait about 4 weeks after repotting pelargonium x domesticum 'lavender grand slam'. Fresh mix already contains nutrients, and feeding freshly cut or disturbed roots burns them. Resume your normal feeding routine once you see new growth.