Plan the perfect garden with our interactive tool →

Do Mums Do Better in Sunlight or Shade?

Mums (Chrysanthemum spp.) grow and flower best in full-sun conditions, though some tolerate or prefer light shade for part of the day. They are perennial plants that can grow in the garden year-round and are also sold as fall-flowering annuals. Whether you grow mums as annuals or perennials, they flower best when given enough sunlight.

Sun Preferences

Mums require at least six hours of sunlight every day during the summer months. For the best flowers, mums also need fertile, well-drained garden soil or potting mix. These preferred growing conditions are shared by all varieties of garden mums.

Hardy garden mum (Chrysanthemum morifolium, also called Dendranthema morifolium) grows 1 to 3 feet tall and has a wide range of flower colors. It is hardy in U.S. Department of Agriculture plant hardiness zones 5 through 9 and, like other mums, requires full sun. Though they share growing preferences, mum cultivars come in a wide range of sizes and colors. 'Sweet Peg' (Chrysanthemum 'Sweet Peg') is a compact variety which grows 8 to 12 inches tall, has pink flowers and is hardy in USDA zones 5 through 9. The taller variety 'Bronze Elegans' (Chrysanthemum ‘Bronze Elegans’) grows at least 3 feet tall, has bronze-red flowers and is hardy in USDA zones 4 through 9.

Effects of Shade

Though mums can tolerate light shade, they become weak and spindly when they do not get at least six hours of sunlight. Shaded plants also produce fewer flowers. The only situation where shade can be beneficial is when you can supply afternoon shade in warm climates to help keep the plants cool.

  • Hardy garden mum (Chrysanthemum morifolium, also called Dendranthema morifolium) grows 1 to 3 feet tall and has a wide range of flower colors.
  • The taller variety 'Bronze Elegans' (Chrysanthemum ‘Bronze Elegans’) grows at least 3 feet tall, has bronze-red flowers and is hardy in USDA zones 4 through 9.

To help keep lightly shaded plants compact, pinch 1 inch off the stem tips when the plants reach 6 to 8 inches tall and then again when the new growth is 6 inches tall. You can also pinch plants in full sun to encourage branching. Pinching, even when done in the late spring or early summer, will delay flowering by a few weeks. For more open plants that bloom earlier in the fall, do not pinch.

Day-Length and Flowering

When mums flower is directly influenced by how much light they receive. Mums are "short-day plants," which means they need the longer nights that accompany the fall season to trigger flowering. Mums start to set flower buds once they get at least 11 hours of darkness at night.

  • To help keep lightly shaded plants compact, pinch 1 inch off the stem tips when the plants reach 6 to 8 inches tall and then again when the new growth is 6 inches tall.
  • Pinching, even when done in the late spring or early summer, will delay flowering by a few weeks.

This doesn't change the fact that mums need full-sun growing conditions, but it does influence where you plant mums. Do not plant mums near a street lamp or porch light, since artificial light will affect their bloom cycle and may result in fewer flowers.

Related Articles

Flowers That Need Morning Sun Only
Flowers That Need Morning Sun Only
How to Care for the Primrose Flower
How to Care for the Primrose Flower
Spring Mum Plants
Spring Mum Plants
How to Keep Dianthus Blooming
How to Keep Dianthus Blooming
Hanging Basket Plant Identification
Hanging Basket Plant Identification
Flowers That Look Like Impatiens
Flowers That Look Like Impatiens
Flowers That Look Like Pansies
Flowers That Look Like Pansies
How to Care for a Lobelia Plant
How to Care for a Lobelia Plant
Flowers That Don't Need Much Sun
Flowers That Don't Need Much Sun
Do Geraniums Need Full Sun All Day?
Do Geraniums Need Full Sun All Day?
How to Pinch Geraniums
How to Pinch Geraniums
Outdoor Mum Plant Care
Outdoor Mum Plant Care
Tall Perennials for Shade
Tall Perennials for Shade
South Texas Winter Flowers
South Texas Winter Flowers
Flowers Native to Germany
Flowers Native to Germany
Common Annual Flowers in New York
Common Annual Flowers in New York
List of Bedding Plants
List of Bedding Plants
Garden Guides
×