Soil & potting mix
Best soil for 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.
Preferred mix: Free-draining loam-based potting mix
Why pelargonium x domesticum 'lavender grand slam' needs this mix
Pelargonium x domesticum 'Lavender Grand Slam' is a Mediterranean dry-hillside plant — it wants a lean, sharply drained, slightly alkaline mix, and rots fast in rich, water-holding soil.
- Pelargonium x domesticum 'Lavender Grand Slam' evolved on stony, sun-baked slopes — its roots expect to dry out hard and quickly between rains, so the mix must drain almost as fast as you pour.
- A lean, low-nutrient mix keeps growth firm and aromatic; a rich one gives soft, sappy, flavourless growth that flops and rots.
- It tolerates and often prefers a slightly alkaline soil, the opposite of most houseplants.
For the full picture on what makes up a good mix, see our guide to the main types of soil and potting media — it explains why each ingredient above behaves the way it does.
What goes wrong with the wrong mix
The wrong soil is one of the most common reasons pelargonium x domesticum 'lavender grand slam' struggles, and the damage often shows up weeks later as a watering problem. For this species specifically:
- Rich, moisture-holding compost is the classic killer of pelargonium x domesticum 'lavender grand slam' — especially over a cold, wet winter, when the base of the plant simply rots.
- A peaty, acidic potting mix is doubly wrong: too wet and the wrong pH direction.
- No grit means the rootball stays damp for days, which a dry-climate root system never copes with.
Growing pelargonium x domesticum 'lavender grand slam' in ordinary rich, moisture-retentive compost. Lean it out with at least a third grit, and never let it sit wet over winter.
pH — does it matter for pelargonium x domesticum 'lavender grand slam'?
Pelargonium x domesticum 'Lavender Grand Slam' likes neutral to slightly alkaline soil, roughly pH 6.5-7.5. If your soil or compost is acidic, a little garden lime or extra grit nudges it the right way — the one common plant where you may add lime.
If you want to check or adjust it, the soil pH guide walks through testing and the safe ways to nudge a mix more acidic or more alkaline.
DIY mix vs a bagged one
Bagged "herb" or "Mediterranean" mixes are usually fine for pelargonium x domesticum 'lavender grand slam', but most standard composts need cutting hard with grit. The DIY ratio above is cheap and exactly right.
Drainage and the pot
Sharp drainage is everything: a terracotta pot with a big hole, gritty mix and never a saucer left full. Raised beds suit these herbs outdoors for the same reason.
A gritty mix barely breaks down, so pelargonium x domesticum 'lavender grand slam' needs little repotting — refresh the top layer and the grit every couple of years rather than potting on aggressively. When the time comes, our repotting guide for pelargonium x domesticum 'lavender grand slam' covers the timing and technique step by step.
Pelargonium x domesticum 'Lavender Grand Slam' soil — frequently asked questions
What is the best soil mix for pelargonium x domesticum 'lavender grand slam'?
2 parts standard peat-free compost or loam : 1 part coarse horticultural grit : 1 part perlite or coarse sand. Pelargonium x domesticum 'Lavender Grand Slam' evolved on stony, sun-baked slopes — its roots expect to dry out hard and quickly between rains, so the mix must drain almost as fast as you pour.
Can I use normal potting soil for pelargonium x domesticum 'lavender grand slam'?
Rich, moisture-holding compost is the classic killer of pelargonium x domesticum 'lavender grand slam' — especially over a cold, wet winter, when the base of the plant simply rots. Bagged "herb" or "Mediterranean" mixes are usually fine for pelargonium x domesticum 'lavender grand slam', but most standard composts need cutting hard with grit. The DIY ratio above is cheap and exactly right.
Does pelargonium x domesticum 'lavender grand slam' need a special pH?
Pelargonium x domesticum 'Lavender Grand Slam' likes neutral to slightly alkaline soil, roughly pH 6.5-7.5. If your soil or compost is acidic, a little garden lime or extra grit nudges it the right way — the one common plant where you may add lime.
Should I buy a bagged mix or make my own for pelargonium x domesticum 'lavender grand slam'?
Bagged "herb" or "Mediterranean" mixes are usually fine for pelargonium x domesticum 'lavender grand slam', but most standard composts need cutting hard with grit. The DIY ratio above is cheap and exactly right.
How often should I refresh the soil for pelargonium x domesticum 'lavender grand slam'?
A gritty mix barely breaks down, so pelargonium x domesticum 'lavender grand slam' needs little repotting — refresh the top layer and the grit every couple of years rather than potting on aggressively. Sharp drainage is everything: a terracotta pot with a big hole, gritty mix and never a saucer left full. Raised beds suit these herbs outdoors for the same reason.
Keep reading
- Pelargonium x domesticum 'Lavender Grand Slam' care — the full brief (light, water, humidity, problems, pet safety)
- How often to water pelargonium x domesticum 'lavender grand slam' — the schedule the mix feeds into
- Repotting pelargonium x domesticum 'lavender grand slam' — when and how to refresh the mix
- Soil pH guide — test it and adjust it safely
- Overwatered plant — signs and recovery
- Root rot — how the wrong soil starts it, and how to save the plant
- Should I water my plant? The simple check first
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- All 5561 soil and potting-mix guides in the Growli library