Chrysanthemums are easy-growing perennial bloomers that provide fall colour for many years with minimal attention, as long as the plants have benefit of well drained soil and plenty of sunshine. Chrysanthemums are versatile plants, ranging from tiny button mums to giants as big as dinner plates, and an interesting array of forms including single, daisylike blooms to full, double-pompom types. Colours range from soft pastels to bold burgundy and maroon. Division is a simple, dependable method of propagating chrysanthemums.
Divide your chrysanthemum for propagation when you notice healthy new shoots emerging from the soil in early spring. To divide the plant, use a digging tool such as a garden fork or spade to dig in a circle around the circumference of the plant. When you've completed the circle, insert the tool deeply under the plant, then lift the clump carefully from the ground.
Remove any dead foliage from last season, then shake the clump to remove loose soil to allow you to see the roots. Pull the clump into smaller divisions, using your hands, a trowel or a sharp knife. Don't make the divisions too small, as each one needs at least three to five shoots and a healthy root system. Place the divisions in a cool, shady place until you're ready to plant.
Return the main clump to its planting hole. If the chrysanthemum plant has been in the ground for three to five years, remove any old, woody growth from the middle of the clump.
Plant the newly-divided chrysanthemum plants in a well-drained location where the plants will be exposed to full sunlight. Before planting, prepare by digging the top 8 to 10 of soil, then work in 2 to 4 inches of organic matter such as compost or rotted manure. Alternatively, use a balanced, granular fertilizer instead of organic material. Apply the fertilizer at a rate of 3 to 4 lbs. for every 100 square feet of garden space.
Water the chrysanthemums deeply enough to saturate the roots, then keep the soil moist until you see new shoots indicating that the plant has successfully rooted. Thereafter, chrysanthemums are relatively drought-tolerant but will benefit from water to a depth of 6 to 8 inches whenever the soil feels dry during warm, summer months.