How to Grow: Sour Gum

Gerd Eichmann

Nyssa sylvatica

 

Other Name

Black tupelo

 

Sun Requirements

Full sun, part sun

 

Bloom Period and Seasonal Color

Mostly grown for its stature and showy fall foliage colors of orange, red and purple.

 

Mature Height x Spread

30 to 50 feet x 20 to 30 feet with some dwarf versions

 

Added Benefits

Native, attracts beneficials, fall color, drought tolerant

 

If you’re looking for an attractive, low maintenance, deciduous shade trees for your street or yard with amazing fall foliage color, add sour gum to your list. This native is an under utilized tree. It has many the qualities we look for in a good shade tree. Sour gum has a pyramidal-shape that grows slowly up to 50 feet tall when mature. The flowers are insignificant, but a good source of pollen for bees in spring. It has small, blue-black fruits that birds enjoy. It grows well in wet sites and can even grow in areas with standing water. But is also drought tolerant. And it has consistently beautiful scarlet red, fall foliage color that makes this tree glow in autumn.

 

When, Where and How to Plant

Sour gum is hardy throughout New England. Purchase trees from a local nursery or through the mail. Plant trees in spring in well-drained, slightly acidic, moist soils. Sour gum produces the best growth and fall color in a full sun location. It has a taproot, so is difficult to transplant successfully once established. Space trees 20 to 30 feet apart.

 

Growing Tips

Keep young trees well watered. Mulch trees with pine needles, bark mulch or wood chips. Create a mulch ring around the trees grown in the yard to keep the soil moist and prevent damage to the trunk due to string trimmers and lawn mowers. Once established sour gum trees are drought tolerant. Fertilizer young trees in spring with an acid-based, tree plant food. Older trees don’t need fertilization.

 

Regional Advice and Care

Sour gum is a carefree tree. Prune in autumn, to reduce sap loss, to remove competing branches or dead, diseased or broken limbs. Although slow growing, plant the tree where it won’t eventually interfere with buildings and overhead power lines. Sour gum has few major pest problems.

 

Companion Planting and Design

Plant sour gum trees as street trees away from power lines or in the yard as a shade tree. Protect them from winter winds in colder parts of our region. Since they tolerate wet conditions, plant in a boggy or seasonally flooded areas of your yard. They can also naturalize in a woodland setting along a stream or pond. Sour gums are salt tolerant, so good choices near the coast.

 

Try These

‘Miss Scarlet’ is known for its deep green summer foliage that turns a brilliant red in fall. ‘Forum’ is a standard selection with a more upright habit that looks more like a pear or linden than sour gum. The fall leaves are red with yellow veins. ‘Autumn Cascades’ is a weeping form that only grows 15 feet tall, but still has the beautiful fall foliage color. It’s only hardy to zone 5.

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