Blackgum (Nyssa sylvatica)

How much light does a Blackgum need?

Outdoors, blackgum takes full sun or part shade. Full sun is the preferred exposure, so give it that when your site allows. Part shade is also listed as acceptable. Shade deeper than part shade is not listed for this tree. Plan for full sun first and part shade second when you compare sites.

• Light: Full sun and part shade (full sun preferred)^1,2,3,1

How often to water a Blackgum

Blackgum tolerates soil moisture from dry to wet. It tolerates poorly drained soils and standing water. It also tolerates some drought and some dry soils, at least in the wild. The soil drainage listed for it includes moist, occasionally dry and occasionally wet conditions. Well drained soil is listed as well.

• Water: Dry to wet³

Best soil for a Blackgum

Blackgum grows in soils that are well drained, moist, occasionally dry, occasionally wet or poorly drained. Its best conditions are described as acidic, medium to wet, well-drained soil with full sun to part shade. The soil pH range is 5 to 7.4. That runs from acid to neutral soil. Occasionally saturated or very wet soil is within the range it handles. It also handles occasional periods of dry soil.

• Soil drainage: Well drained, moist, occasionally dry, occasionally wet and poorly drained^4,2
• Soil pH: pH 5–7.4⁴

Hardiness and temperature

Blackgum is hardy in USDA zones 4a to 9b. That covers every half-zone step from 4a, 4b, 5a and 5b through 9a and 9b. Zone 4a is the coldest zone listed and zone 9b is the warmest. No cited source records a minimum temperature for this tree. Humidity needs are not documented either. If your garden sits in zones 4a through 9b, it falls within the listed range.

• Hardiness: Zones 4a–9b³

How to plant a Blackgum

Blackgum is suited to planting in USDA zones 4a to 9b. Its mature height is 30–50 ft (9.14–15.24 m). Leave room for a mature spread of 20–35 ft (6.1–10.67 m). It prefers full sun, and part shade is also listed. It is a deciduous tree and native to the lower 48 US states.

• Hardiness: Zones 4a–9b³

Winter care

Blackgum is a deciduous tree. It is listed for zones 4a to 9b, which includes cold-winter zones such as 4a. No cited source records a minimum temperature, so this page gives no winter low. Winter protection steps are not documented. Gardeners in zone 4a sit at the cold edge of the listed range. Gardeners in zone 9b sit at the warm edge of it.

• Hardiness: Zones 4a–9b³

How to propagate a Blackgum

You can propagate blackgum by seed or by layering. Those are the two methods listed for this tree. Both apply to a deciduous species native to the lower 48 US states. Seed treatment, timing and rooting conditions are not documented for either method. Cuttings, grafting and other methods are not documented either. Because the methods are listed without detail, this page does not describe the steps.

• Propagation: Seed and layering³

Common problems

No common pests are recorded for this tree. Leaf spot, canker and rust are its common diseases. It has some susceptibility to leaf spots, cankers and rust. Leaf spots, cankers and rust are the problems to watch for on this tree. Prevention and treatment steps are not documented for these diseases.

• Common pests: ⁴
• Common diseases: leaf spot, canker and rust^3,2

Questions and answers

How much sun does blackgum need?

Blackgum grows in full sun or part shade, and full sun is the preferred exposure. Shade deeper than part shade is not listed for this tree. Part shade is listed as acceptable.

Will blackgum grow in wet soil?

Blackgum tolerates poorly drained soils and standing water. It also tolerates some drought and some dry soils, at least in the wild. Its listed soil pH runs from 5 to 7.4.

How big does blackgum get?

Blackgum is a deciduous tree with a mature height of 30–50 ft (9.14–15.24 m). Its mature spread is 20–35 ft (6.1–10.67 m). It is listed for USDA zones 4a to 9b.