The "King of Trees" Catalpa: Appearance, Symbolism, Seed Prices, and Planting Methods

Catalpa, also known as zi, qiu, huaqiu, shutong, heqiu, chou wutong, huanghuaqiu, shutongqiu, mujiaodou, is a tree species in the genus Catalpa of the Bignoniaceae family, reaching up to 15 m tall. So what does it look like? What does it symbolize? How much do the seeds cost per jin? What are the planting methods? According to the Jiangxi nursery base, the price of catalpa seeds is around 28 yuan per jin. The sowing rate per mu is 5--6 jin.

What does catalpa look like?

1. Catalpa, Bignoniaceae, genus Catalpa. It is a deciduous tree, generally 6 m tall, with a maximum height of 15 m. The crown is umbrella-shaped, the trunk is straight and smooth, dark gray or grayish brown, and the young branches have sparse soft hairs.

2. The panicle is terminal, 10-18 cm long, the peduncle is slightly sparsely hairy, 12-28 cm long; the pedicels are 3-8 mm long, sparsely hairy; the calyx is spherical, splitting into 2 lips, 6-8 mm long; the calyx is 2-lobed, the lobes broadly ovate, apex acute; the corolla is bell-shaped, light yellow, about 2 cm long, bilabiate, the upper lip 2-lobed, about 5 mm long, the lower lip 3-lobed, the middle lobe about 9 mm long, the lateral lobes about 6 mm long, the margin wavy, the tube interior with 2 yellow bands and dark purple spots, about 2.5 cm long, about 2 cm in diameter.

The capsule is linear, pendulous, dark brown, 20-30 cm long, 5-7 mm thick, and does not fall in winter; the leaves are opposite or nearly opposite, sometimes whorled, broadly ovate, length and width similar, about 25 cm long, apex acuminate, base cordate, margin entire or slightly wavy, often 3-lobed, both surfaces rough, slightly covered with soft hairs or nearly hairless, with 4-6 pairs of lateral veins and 5-7 palmate veins at the base; the petiole is 6-18 cm long; the seeds are oblong, densely covered at both ends with long soft hairs, about 3 cm long including the hairs, about 3 mm wide, slightly raised on the back. Fertile stamens 2, the filaments inserted on the corolla tube, the anthers divergent; staminodes 3. Ovary superior, clavate. Style filiform, stigma 2-lobed. Flowering period June-July, fruiting period August-October.

3. It has strong adaptability, prefers warmth, and can also tolerate cold. Deep, moist, fertile sandy loam is better for the soil. It is not tolerant of drought or barren soil. It has strong pollution resistance and grows relatively fast. It can be planted in odd corners and gaps of land. It grows in low mountain valleys at an altitude of 500-2500 m, in moist soil; wild individuals are no longer seen, and it is mostly cultivated near villages and along roadsides.

What does catalpa symbolize?

This can also be confirmed in the line from Chen Lin's "Proclamation for Yuan Shao to Yuzhou" at the end of the Han dynasty: “Again, King Xiao of Liang, the younger brother of the former emperor, his tomb is honored and prominent; the pines, cypresses, mulberries, and catalpas should still be treated with reverence.” This is because in the minds of the ancients, the mulberry tree, with its extremely strong ability to regenerate branches, and the catalpa, which grows quickly and has excellent timber, were both trees of life, and people regarded them as sacred trees. Therefore, people who wandered abroad and lived in other places for various reasons would often suddenly feel longing for their relatives, a sense of reverence, and homesickness when they saw these two kinds of trees. Over time, the mulberry and catalpa became symbols of one's hometown, and “sangzi” also became a byword for one's hometown.

What are the planting methods for catalpa?

Suitable environment for catalpa

The quality of the soil directly affects how well catalpa seedlings grow, and even more directly affects whether the seedlings develop robustly. If the soil is very good and the growing environment is very good, then tending them will be much simpler, and the quality and development speed of the seedlings will also improve a great deal accordingly. Catalpa is not strict about soil requirements and can be planted in sandy soil, loess, clay, or soil with a high sand content without much issue. But for raising seedlings, high-quality fields should be chosen that have loose, aerated soil, rich organic matter, flat terrain, and smooth drainage. When summer comes, there is more rain, and the rainwater must be able to drain away immediately; otherwise, some seedlings will die. The main point of the terrain is that it should be conducive to draining accumulated water; ordinary soil is about enough, and with sufficient sunlight, catalpa has very good cold resistance, drought tolerance, and waterlogging tolerance.

Land preparation

1. Plowing: Catalpa seedlings are very sensitive to soil nutrients. Only when the soil nutrients are sufficient will they grow glossy green and vigorous, and the plants healthy. But the soil in some fields is basically of a terrain with similar nutrients. Precisely because of this, if you want the seedlings to grow thick and sturdy, you still need to apply sufficient base fertilizer before sowing, spreading 3~6.5 thousand kg of cow dung and sheep manure per mu, then plowing once and harrowing once after fertilizing, so that the soil and fertilizer are evenly mixed together with moisture, with no large clods of soil, making it convenient for sowing and germination.

2. Making beds: In order to facilitate irrigation, weeding, fertilizing, and other necessary maintenance measures throughout the entire growth period of catalpa seedlings, Changjing Landscape suggests making the land into fixed beds 1.4 m wide and 16~25 m long in total, depending on the specific topography.

Planting

Catalpa seeds are generally medium in size and have a very good germination rate. Before sowing, some scarification methods can be appropriately used. Some of the steps are actually very simple: soak in clean water for 1 day, then take them out and dry the surface, and they can be planted. The sowing depth should be moderate or very shallow; the soil covering depth should not exceed 4 cm. Most use drilling. After sowing, a moisture-retaining film or moisture-retaining material such as wheat straw can also be laid down to increase the germination rate. After sowing, manual raking of soil can be used for covering, or mechanical raking of soil for covering. After covering with soil, irrigate once, and germination can occur in about 7~12 days.

Care

There is relatively little maintenance work during the catalpa seedling stage. It has few diseases and pests, and its development is strong. The most critical tasks are only irrigation, weeding, and pest control. During the peak growth period of huangqi, a large amount of water and fertilizer is required. During this period, 40 kg of chemical fertilizer can be used per mu. When catalpa is growing fastest, sufficient water is also required. At this time, watering should be done at the right opportunity according to the weather conditions.