Ornamental Allium
Allium giganteum, A. hollandicum and hybrids
Ornamental alliums are bulbs that send up tall, straight stems topped with perfect spheres of tiny purple, white or pink flowers in late spring. Bees adore them, and the seed heads stay decorative for months.
Photo: Wadester16 · CC BY-SA 3.0, via Wikimedia Commons
Essential Care Requirements
Light
Full sun
Watering
Low
Water in spring if dry; keep drier after flowering.
Soil
Well-drained soil; pH 6.0–7.5.
Temperature and humidity
-30–32 °C · Low humidity
Feeding
Feed with bulb fertilizer at planting.
Pruning and propagation
Propagate by offsets, seed
Leave seed heads standing for decoration; remove leaves once yellow.
Like onions, alliums are toxic to cats and dogs.
Top Cultivation Tips
Plant bulbs in autumn, 15 cm deep.
Plant among perennials to hide the fading leaves.
Dry seed heads for arrangements.
Deer and rodents avoid them.
Common problems
Root rot
Roots decay in waterlogged soil, so the plant wilts and yellows even though the soil is wet.
How to treat it →DiseaseRust
A fungal disease that forms orange, brown or yellow powdery pustules, mainly on leaf undersides.
How to treat it →PestThrips
Tiny, slender insects that rasp leaf and flower surfaces, leaving silvery streaks, curled leaves and distorted flowers.
How to treat it →
