how deep to plant allium bulbs

Allium bulbs should generally be planted at a depth about two to three times the height or diameter of the bulb. For example, large allium bulbs, which are typically around 4 to 6 cm (1.5 to 2.5 inches) in diameter, should be planted about 12 to 15 cm (4 to 6 inches) deep. Smaller bulbs are planted shallower, around 7 cm (3 inches) deep. It is important that the bulb is completely covered with soil. Plant the bulbs with the pointed side facing up to aid proper growth. After planting, watering and firming the soil around the bulb helps with establishment. Spacing varies with bulb size, generally 10-20 cm apart for large bulbs and 5-10 cm for smaller ones. These guidelines are for fall planting before the soil freezes to ensure strong root development.