How to Care for Allium Giants

Plant giant allium bulbs in beds that receive full sunlight. Choose a bed with rich, well-drained soil.

Water the alliums once weekly when the top inch of soil has dried. Supply about 1 inch of water a week or enough to maintain moisture in the top 6 inches of the soil bed. Alliums don't require watering in the fall and winter dormant period.

Cut back the plants in fall once the foliage has died back to the ground. Shear off the old stems and leaves at the soil surface.

Replenish the mulch layer on the bed yearly in fall when the ground begins to freeze. Cover the bed with a 4-inch layer of wood or pine straw mulch.

Fertilize the bulbs annually in early spring as new growth begins. Apply a balanced fertilizer or a fertilizer formulated for flowering bulbs at the rate on the package.

Divide alliums every two to three years after the plants finish flowering in summer. Dig up the old bulbs and separate them. Replant the bulbs 4 inches deep and space them 2 feet apart.