How to Grow and Care for Smooth Sumac

Smooth sumac is a deciduous native shrub or small tree with a moderate growth rate that forms an impressive display during its bloom in the spring or early summer. The plant produces yellowish-green flowers in upright cone-shaped panicles up to ten inches long. The female plant then produces hairy pyramidal clusters of drupes that ripen to a beautiful bright red in the fall. Smooth sumac grows in full sun and part shade in well-drained soil. It is a pioneer plant that thrives in conditions other plants do not find hospitable, including dry or poor soil. Because it rapidly forms dense colonies and thickets, it is not suitable for shrub borders and small spaces. Instead, it should be planted in large, naturalized areas where its spreading does not endanger surrounding vegetation.

Smooth Sumac Care

Here are the main care requirements for growing smooth sumac:

• Plant smooth sumac in the spring or fall.
• Choose a location ideally in full sun and with well-drained soil.
• To contain the spread, consider installing a root barrier at least 2 feet deep in the soil.
• Water deeply once a week during the first growing season if it doesn’t rain.
• Do not fertilize smooth sumac.
• Prune the shrub to remove dead wood and remove suckers regularly to contain the spread.
  

Light

Smooth sumac grows best in full sun and partial shade. Blooms will be more profuse in full sun, and fall colors will be more vibrant.

Soil

Smooth sumacs are adaptable to many soil types, as long as it is well-drained. The sumac is adaptable to a range of pH levels between 5.0 and 8.0.

Water

Until the shrub establishes itself, you should irrigate it regularly by providing a deep drenching watering about once a week during the first growing season. Smooth sumac does well in dry to average moisture areas; once established, no watering other than rainwater is necessary. It is somewhat drought tolerant.

Temperature and Humidity

The smooth sumac tolerates a wide range of temperature and humidity. This includes temperate and subtropical regions. Still, smooth sumacs grow best in warm, humid environments.

Fertilizer

There is no need to fertilize smooth sumacs. It grows adequately in poor soil without any amendments. 

Types of Smooth Sumac

• Cutleaf smooth sumac (Rhus glabra ‘Laciniata’): Cultivar with delicately dissected green leaves that turn orange-red in the fall. The shrub grows up to 10 feet tall and 12 feet wide. Zone 2-9 (USDA) 
• Rocky Mountain sumac (Rhus glabra var. cismontana): A variety of smooth sumac that is native to Colorado and other places in the Rocky Mountains. It has dark green compound leaves that turn brilliant red in the fall. The shrub only grows 3 to 6 feet tall and 3 to 10 feet wide, about half the size of the smooth sumac. Zone 2-9 (USDA)

Pruning

Prune your smooth sumac in early spring by removing any dead, dying, or diseased branches with pruning shears. Light pruning promotes healthy growth. Remove suckers using loppers by cutting them to the ground or pruning 1/4 of the oldest branches.

Propagating Smooth Sumac

You can propagate smooth sumac using root cuttings. Propagating it this way has the highest success rate. Here's how:

1. In the early spring, before the leaves emerge, take a 6-inch cutting from a healthy smooth sumac.
2. Fill a 4-inch pot with loose soil mixed with sand or perlite. Dip the cut end in rooting hormone and insert it in the pot about halfway deep.
3. Place the pot in a bright spot but away from direct sunlight.
4. Keep the soil moist but not wet. After roots have started to form and the sapling has leafed out, let it grow for at least one summer in pots, watering it well, before transplanting it in the landscape.

How to Grow Smooth Sumac From Seed

Starting sumac from seed is better left to nature. The germination of the seeds is enhanced by acidification when the seeds pass through the digestive system of rabbits, pheasants, and quail, as well as by wildfires.

Potting and Repotting Smooth Sumac

Due to its size, smooth sumac is not suitable to be grown in a container. For potted sumac, choose a small variety of staghorn sumac such as Rhus typhina ‘Tiger Eyes’.

Overwintering

Smooth sumacs are very hardy plants that don't require any overwintering measures. During the winter, they go into dormancy and will not suffer from low temperatures. However, saplings grown in pots should be winterized to protect their roots against frost damage.

Common Pests & Diseases

Smooth sumac is not affected by serious pest or diseases problems. It is susceptible to leaf spot, rust, scale, aphids, and mites.

How to Get Smooth Sumac to Bloom

Bloom Months

Smooth sumac typically blooms in June or July.

How Long Does Smooth Sumac Bloom?

The bloom lasts for a few weeks.

What Do Smooth Sumac Flowers Look and Smell Like?

Smooth sumac produces clusters of green, yellow, or white flowers. The flower has hairy, pointed lobes and stems that will become smoother with time. The flowers do not have a particular smell.

How to Encourage More Blooms

Planting smooth sumac in full sun is the best way to ensure it blooms profusely.

Caring for Smooth Sumac After It Blooms

No care is needed for smooth sumac after it blooms. Deadheading the flowers after the blooms is not practical and it does not prevent the shrub from spreading aggressively as this occurs through root suckers.