Black gum: allround coastal garden choice

Black gum

There’s fall colour, and then there’s knock-your-socks-off-and-fall-down colour. Black gum tree contributes to the latter. This all-purpose, mid-sized North American native puts on a technicolor show in autumn, when the leaves morph from yellow to orange to red or purple in a matter of weeks. It’s considered one of the most beautiful and most consistent native trees for colour, which means it doesn’t stall out every other year at the dull yellow-green stage. And though it won’t attract as much attention from you in the spring and summer, it does attract other fans: butterflies love its flowers’ nectar and birds love the sour fruit that follows.

Common name: Black gum, sour gum, tupelo

Botanical name: Nyssa sylvatica

Plant type: Deciduous tree

Zones: 3 to 9

Height: 30 to 50 feet tall; rarely to 70 or 90

Family: Cornaceae

Growing conditions

• Sun: Full sun to part shade

• Soil: Rich, acidic

• Moisture: Average to moist. Tolerates both standing water and some drought. 

Care

• Mulch: Mulch to help keep soil moist.

• Pruning: None needed

• Fertilizer: None needed

Propagation

• By seed

Pests and diseases

• Leaf miners, caterpillars, and scale insects may be problems.

• May be vulnerable to wood rot, canker, and leaf spots.

Garden notes

• Black gum is usually dioecious, meaning there are female and male trees. Occasionally “perfect” flowers (with both male and female parts) are found on one tree, but if you want your black gum to produce a lot of fruit, plant a male and a female tree to ensure pollination.

• Though black gum has a reputation for being difficult to transplant because of its long taproot, this shouldn’t be a problem with a young nursery-grown tree. Be sure to put it in the right place (give it room to grow to its mature size), however, so you don’t have to move it later.

• This is one of the very few trees that will tolerate poor drainage. Black gum can actually grow in standing water—though it is also found in the wild on dry mountainsides and can tolerate some drought.

All in the family

• The genus Nyssa contains only about five to ten species. They’re found in Asia and North America. A close relative of black gum, water tupelo (Nyssa aquatica), grows in the swamps and coastal areas of the southeastern United States, sometimes alongside bald cypress and water oaks.

• Nyssaceae, the tupelo family, is likewise quite small. It includes only five genera and about 20 species, most of which are found in Asia.

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