Yellow Catalpa (Catalpa ovata)

Chinese catalpa is a flowering, pod-bearing tree native to China, but cultivated as an ornamental tree in Europe and North America as well. When bruised, the tree releases a pleasant scent. Due to the appearance of the three-lobed leaves, chinese catalpa is sometimes confused with Paulownia tomentosa.

I. Appearance and Characteristics 

Catalpa ovata, the yellow catalpa or Chinese catalpa (Chinese: 梓; pinyin: zǐ), is a pod-bearing tree native to China. Compared to C. speciosa, it is much smaller, typically reaching heights between 20 and 30 feet (6 and 9 m). The inflorescences form 4–10-inch-long (100–250 mm) bunches of creamy white flowers with distinctly yellow tinging; individual flowers are about 1 inch (25 mm) wide. They bloom in July and August. The leaves are very similar in shape to those of Paulownia tomentosa, having three lobes (two are abruptly truncated on either edge, with a third, central, slightly acute, pointed lobe forming the leaf apex), and are darkly green. Fruits are very narrow, foot-long pods.

Although native to the more temperate provinces within China (Anhui, Gansu, Hebei, Heilongjiang, Henan, Hubei, Jiangsu, Jilin, Liaoning, Nei Monggol, Ningxia, Qinghai, Shaanxi, Shandong, Shanxi, Sichuan, Xinjiang), C. ovata is also cultivated in North America and Europe, and has become a parent of Catalpa × erubescens with the American species Catalpa bignonioides. It is commonly used to make the undersides of qin.

II. How to Grow and Care

Chinese catalpa is generally considered an easy-to-care-for plant, with a few key needs for optimal growth. It requires full sun exposure to encourage lush foliage and flowering. Additionally, chinese catalpa is not particularly drought-resistant, so consistent watering is important for maintaining health, particularly in dry conditions. It’s resilient to a variety of soil types, although it thrives in well-draining soil with some regular fertilization.

Sunlight

Chinese catalpa performs best in full sun, though it still grows in partial shade. Choose a bright and sunny area for your chinese catalpa, where it will receive at least 4 hours of direct light per day. If you choose a location with partial shade, expect flowers to be less abundant than a plant grown in full sun.

Temperature

Chinese catalpa is a hardy plant, able to tolerate temperatures as low as -34 ℃. Likewise, it can also survive extremely hot and dry conditions. Once established, the chinese catalpa can tolerate drought and some flooding too.

Watering

Chinese catalpa thrives in environments that mimic its native habitat’s moderate moisture levels. This species exhibits a preference for consistent soil moisture without being waterlogged, showcasing an equilibrium in its water needs. Its watering regimen should reflect this balance, with a schedule of once every two weeks to maintain proper hydration. Chinese catalpa is typically grown outdoors and, as a deciduous plant, it requires less water during its dormancy period in the colder months, allowing for natural seasonal adjustments to its watering routine.

Soil

Moist and fertile soil is ideal for growing the chinese catalpa. However, this hardy plant also does well in a wide range of soil types, including sandy, loamy, silty loam, and clay. It’s not picky about soil pH either, as it thrives in both acidic and alkaline soils. Moreover, it can tolerate some waterlogging, as well as extremely hot and dry conditions, especially once established.

Fertilizing

Fertilize chinese catalpa in spring with a balanced, slow-release fertilizer to encourage robust growth and luscious flowering. Apply quarterly at half the recommended strength to avoid over-fertilization. Adjust quantities as chinese catalpa matures, reducing frequency in dormant winter months. Always water thoroughly post-fertilization to distribute nutrients and prevent root burn. For optimal health, adhere strictly to season-specific needs and avoid excessive feeding, ensuring a beautiful display from chinese catalpa.

Planting Instructions

Growing chinese catalpa from an established seedling is a lot easier than planting from seed. Plant nurseries and garden centers often have ready-to-plant seedlings available. Spring is the best time of year to transplant the chinese catalpa.

When transplanting, prepare a hole that is twice as deep and wide as the seedling’s root ball. Position the plant so that the top of the root ball is at ground level. Then, spread the roots and fill in the hole with well-draining soil. Once planted, stake the young plant to help it grow upright. Water thoroughly.

Pruning

Pruning will help to encourage new growth on your chinese catalpa, while keeping it to a manageable size. Start pruning your plant in the spring, one year after planting. As it grows, prune it regularly to maintain a healthy form and remove low-growing, weak, and damaged branches. Cut off any deadwood, water sprouts, and suckers using a pair of clean and sharp pruning shears.

Propagation

Chinese catalpa is a deciduous tree known for its broad, heart-shaped leaves and showy white flowers. It thrives best in moist, well-drained soil and full sun exposure. For effective propagation, seeds should be collected from ripe pods and sown in a cold frame as soon as they’re obtained. Prior to sowing, stratify seeds to enhance germination rates. Utilize a growth medium that is fertile and maintains adequate moisture. Gentle handling of seedlings is crucial during transplanting to avoid root disturbance.

Transplanting

The ideal timing for the transplantation of chinese catalpa falls between late winter and early spring (season S1-S2); this is when the plant’s dormancy period offers the least shock. Chinese catalpa thrives in well-draining soil located in semi-shade areas. When transplanting, carefully preserve root balls to promote healthier recovery. This advice is based on established horticultural practices and ensures a successful transplant.