PlantSowGrow
How to grow Allium (Purple Sensation)
Allium hollandicum 'Purple Sensation'
Striking purple drumstick flower balls in May and June, adored by bees. Seedheads look great into summer.
At a glance: Sow early September to mid October.
When to sow, plant and harvest
Timed for a typical UK garden (last frost mid-April). The app uses your own town's frost dates.
Growing Allium (Purple Sensation): what it needs
- Light
- Full sun · 6+ hours a day
- Watering
- Water pots in dry spells while in leaf; keep drier when dormant
- Soil
- Well-drained soil or bulb compost
- Spacing
- 20 cm
- Height
- 90 cm
- In pots
- Grows well in containers
- Feeding
- A little general feed in spring
- Hardiness
- USDA zones 3–8
Step by step
- Early September – mid October · 6 weeks before the first autumn frost
Plant Bulbs
Plant 10–15 cm deep and 20 cm apart, pointy end up, in well-drained soil or pots. Water in.
- 100–150 days after “Plant Bulbs” · Mid December – early February
Look for Shoots
Green shoots should be showing. Keep pots moist but not wet and watch for slugs on young leaves.
Every year
- MayIn Flower
Your bulbs should be in flower — a good moment for a journal photo.
- JuneDeadhead and Feed
Snap off faded flower heads (not the leaves) and give a high-potash feed to build up the bulb for next year.
- JulyLet the Leaves Die Back
Leave the foliage for at least six weeks after flowering, until it yellows — don't knot or cut it. Then tidy it away.
