Northern Catalpa (Catalpa speciosa)

How much light does a Northern Catalpa need?

Northern catalpa grows in full sun or part shade, and full sun is the preferred condition. Full sun here means six or more hours of direct sunlight a day. Part shade is also a listed growing condition for this tree. When you have a choice of sites, pick the sunnier one.

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

How often to water a Northern Catalpa

Expect low water use from northern catalpa. Dry is the recorded value at both the lower and upper end of its water range. Occasionally wet soil is listed as a condition it tolerates. Occasional periods of dry soil are listed as tolerated too. Moist, well drained soil is also on the same list.

• Water: Dry³

Best soil for a Northern Catalpa

Northern catalpa is listed for well drained and moist soil. The moisture conditions run from occasionally saturated, very wet soil at one end to occasional dry periods at the other. The listed pH range runs from 5 to 8, which covers acid to alkaline soil. A pH of 5.0 to 8.0 is the range given as tolerated. Acid soil and alkaline soil both fall inside that range.

• Soil drainage: Well drained, moist, occasionally wet and occasionally dry⁴
• Soil pH: pH 5–8²

Hardiness and temperature

Northern catalpa is listed for zones 4a to 8b. The listed zones are 4a, 4b, 5a, 5b, 6a, 6b, 7a, 7b, 8a and 8b. Zone 4a is the coldest zone listed and zone 8b the warmest. No cited source records a minimum temperature for this tree. Humidity is not documented here either.

• Hardiness: Zones 4a–8b¹

How to plant a Northern Catalpa

Northern catalpa is listed for planting in zones 4a to 8b. Plan for a large tree, because the listed height is 75–100 ft (22.86–30.48 m). The listed spread is 8–16 ft (2.44–4.88 m). Full sun is the preferred light, and part shade is also listed. The tree is native in the lower 48 US states. Its growth rate is listed as moderate.

• Hardiness: Zones 4a–8b¹

Winter care

Northern catalpa is a deciduous tree. It is listed as hardy from zone 4a to zone 8b. Zone 4a is the coldest zone listed. No cited source records a minimum temperature, so a specific cold limit is not documented here. Winter protection steps are not documented for this species either.

• Hardiness: Zones 4a–8b¹

How to propagate a Northern Catalpa

Three propagation methods are listed for northern catalpa: seed, stem cuttings and root cuttings. The stem cuttings are semi-hardwood cuttings taken in late summer. Root cuttings are taken in late fall. The source says the tree will root from either kind of cutting. Seed is the third listed method, and the evidence on file gives no further detail for it.

• Propagation: Seed, stem cuttings and root cuttings⁵

Common problems

Catalpa worm and whitemarked tussock moth are the pests listed for northern catalpa. Four diseases are listed: leaf spot, powdery mildew, verticillium wilt and Texas root rot. Neither list says how common each problem is. No treatment advice is documented for any of them here.

• Common pests: catalpa worm and whitemarked tussock moth⁶
• Common diseases: leaf spot, powdery mildew, verticillium wilt and texas root rot⁷

Questions and answers

How much sun does northern catalpa need?

Northern catalpa grows in full sun or part shade, and full sun is preferred. Full sun means six or more hours of direct sunlight a day. Part shade is the other listed condition for this tree.

What color are northern catalpa flowers?

The listed bloom colors are white, orange and purple. One description gives large, showy, bell-shaped flowers with frilled rims. Purple and lavender both appear as flower colors in one listing. The listed bloom season runs from April to June.

How big does northern catalpa get?

Northern catalpa reaches 75–100 ft (22.86–30.48 m) tall. The listed spread is 8–16 ft (2.44–4.88 m). Its growth rate is listed as moderate. It is a deciduous tree. It is native in the lower 48 US states.