Plant chrysanthemums in your garden by selecting a location that receives at least five hours of direct sunlight per day, ensuring the soil drains well and putting them in the ground in the early spring. When picking out plants, select those that are just beginning to break bud. Once planted, these mums have a longer flowering period than those already in full bloom at the time of purchase.
Optimally, select a spot that receives between five and six hours of direct morning light with afternoon shade. Use well-draining soil with a 6.5 pH. To increase drainage and fertility, add organic material such as compost or peat to the soil, or plant the mums in a raised garden bed. Dig a hole in the soil large enough to accommodate the plant's root ball. For more than one mum, place the holes at least 18 inches apart to allow for plenty of growth. Especially large cultivars require staking to help support the plants.
Once the mum plants grow to a height of 6 inches, snip off the ends of the branches to encourage the plant to grow bushy instead of leggy. Mums that are pruned back in the spring and summer bloom more heavily in the fall. Mulch the plants after blooming to protect the roots from the cold.