How to Grow: Sweet Gum

Gmihall

Liquidamber styraciflua

 

Other Name

American Sweet Gum

 

Sun Requirements

Full sun, part sun

 

Bloom Period and Seasonal Color

Grown mostly for its tall stature and yellow, red, and purple fall foliage colors

 

Mature Height x Spread

50 to 80 feet x 40 to 60 feet with some dwarf versions

 

Added Benefits

Native, fall color, drought tolerant, deer resistant

 

If you’re looking for something similar to, but different from your usual red or sugar maple trees for fall foliage color and shade, try the sweet gum. This deciduous tree grows up to 80 feet tall in a pyramidal shape, with some dwarf forms. It has maple-like, star-shaped leaves that smell like camphor oil when crushed. The flowers and fruits are not significant, but the fall foliage is outstanding. Depending on the individual tree, leaf colors can include yellow, red, orange, purple and red. The only downside for New Englanders is that sweet gum is only hardy to zone 5, so not all locations in our region can grow this tree.

 

When, Where and How to Plant

Select varieties hardy for your area from a local nursery. Plant in spring to early fall in an open, full to part sun area, avoiding power lines or buildings nearby. Sweet gum grows best on deep, moist, river bottom soils. Space trees 40 to 50 feet apart, closer for dwarf and narrow versions

 

Growing Tips

Keep young trees well watered. Older trees are drought tolerant. Create a mulch ring around the base of young trees grown in lawns covered with bark mulch and wood chips to help keep the shallow roots moist and reduce damage to the trunk due to lawn mowers and string trimmers. Fertilize young trees with a tree plant food. Older trees usually don’t need fertilization.

 

Regional Advice and Care

Prune dead, diseased or broken branches in late winter. Otherwise sweet gum needs little pruning and has few troublesome pests. Avoid high pH soils that may cause a nutrient imbalance. The spiny fruits eventually fall to the ground and can become a litter problem depending on where the tree is planted.

 

Companion Planting and Design

Plant sweet gums in a large backyard, meadow or park-like setting. Older trees develop interesting, corky textured bark. Give it plenty of room to grow tall and wide to get the full effect of its glory. Plant multi-stemmed selections that grow less than 20 feet tall, in among other native trees, such as serviceberry and hawthorn. Sweet gums can also be planted as street trees when given enough room.

 

Try These

‘Moraine’ is the most popular selection and most cold hardy, surviving temperatures in the -25F range.  ‘Gumball’ is a multi-stemmed dwarf selection that grows 15 feet tall and still has good fall color. ‘Slender Silhouette’ grows 50 feet tall, but only 4 feet wide, making it a good choice for narrow spaces. ‘Golden Treasure’ has unique yellow and green leaves, but may not be as hardy as other selections. ‘Silver King’ has white and green variegated leaves.

Excerpted from my book, New England Getting Started Garden Guide.