Plant Allium Globemaster in the fall after approximately two weeks of temperatures that range from 40 to 55 degrees F. Choose a location with full sun and well-draining soil, and maintain a neutral soil pH to encourage plant growth. Apply organic fertilizer to the top layer of soil after planting, when the plants begin to bloom and after the bloom dies. After the foliage dies in late summer, cut the stalks to the ground to encourage growth the following year.
When planting Allium Globemaster, choose a location that receives at least six hours of direct sunlight each day. Plant the bulbs to a depth that is two or three times deeper than the diameter of the bulb, and place the bulb in the hole with the pointed end upward.
To prevent burning the roots, avoid applying fertilizer to them, and monitor the growth of offsets on well-established plants. Transplant the offsets in the fall if the new growth slows the growth of the larger plant.
Cover the ground with a 2-inch layer of mulch after the ground freezes in fall or winter. Water the plants regularly until they are well-established, and weed the garden regularly to promote healthy growth. Established allium is drought-resistant and requires less water than young plants.