Summer heat causes 3000 potted plants and flowers to wither and die at Wuxing Garden in Nanchong, Sichuan

In 2013, our city installed isolation railings in the Wuxing Garden area and planted various flowers and plants in the flower boxes. This move to beautify the urban environment drew rounds of praise from citizens. But recently, well-known netizen “Du Sheng” posted online, saying that flowers and plants in the isolation railing flower boxes in the urban area had withered on a large scale, “It is truly a pity to see. If no management is carried out, the rest may all die off.”

Flower box vegetation withers and dies in patches

On the morning of August 5, the reporter came to Renmin Middle Road in the city and saw various flowers and plants growing in the flower boxes on the isolation railings. It is understood that this layout was originally designed with full consideration of the urban heat island effect. It not only occupies no land, but also has heat insulation and cooling effects, and can also regulate traffic and beautify the city. But regrettably, most of the flowers and plants in the flower boxes had already withered and died. The reporter then went to Shenghuatang Square on Wenhua Road in the city and saw that most of the plants on the flower platforms there had also turned yellow and withered. Similar scenes also appeared in the isolation railing flower boxes on Renmin South Road.

“The withering and death of these flowers and plants not only goes against the original purpose of planting them, but also affects the city's appearance. I hope the landscaping department will promptly strengthen maintenance and restore them as soon as possible,” said citizen Ms. Chen.

Landscaping department: replanting after temperatures drop

At 3:30 pm on August 5, the reporter called the Municipal Landscaping Management Office. A relevant person in charge told the reporter that they had received news of the vegetation withering and dying in the Wuxing Garden area. He said, “The flowers and plants in the isolation railings were planted around 2013. Herbaceous flowers have shallow root systems and are not connected to the ground, making it difficult for them to absorb water. Now, when high-temperature weather occurs, withering and death easily appear.”

According to the person in charge, after receiving news of the vegetation withering and dying in the Wuxing Garden area, they inspected the site, and about 3000 or more pots of flowers and plants had withered and died. However, because the temperature is relatively high, it is currently not suitable for replanting.

“Every morning and evening, 8 water trucks are used to irrigate urban vegetation, with water consumption reaching 200 to 300 tons,” said the relevant person in charge of the Municipal Landscaping Management Office. They will increase maintenance efforts, and after temperatures drop, they will replant the vegetation that withered and died, restoring a beautiful appearance to the city.

Pentas

Pentas, also known as star flower, is a perennial herbaceous plant in the Rubiaceae family. The plant height is 30 to 60 cm. Flowers are terminal, small flowers are tubular, and the corolla is five-lobed and star-shaped, hence the name. Flower colors include purple, pink, white, and others. It can bloom from spring to autumn, and propagation by cuttings can be carried out throughout the year. It prefers a warm environment and grows well between 25°C and 30°C.

Ornamental characteristics and propagation methods of double-petaled winter cherry blossom

The double-petaled winter cherry blossom belongs to the genus Cerasus in the Rosaceae family and shares many morphological characteristics with the winter cherry blossom. It is a native tree species unique to Heqing County, Dali Prefecture, Yunnan Province. Compared with the winter cherry blossom, the double-petaled winter cherry blossom has the excellent characteristics of more flowers, more petals, brighter flower color, and a longer flowering period. It is an excellent native tree species with ornamental characteristics superior to the winter cherry blossom.

1 Overview of double-petaled winter cherry blossom

1.1 Morphological characteristics

The double-petaled winter cherry blossom is a deciduous tree, reaching 5-18 m tall. Leaves are alternate, ovate-lanceolate or oblong-elliptic, with fine sharp serrations along the margins. It has umbel-like racemes, with 3-9 flowers clustered and growing in leaf axils, appearing as a slightly umbellate inflorescence. The calyx tube is obconical, the calyx lobes are shorter than the calyx tube, the style is hairless, and the flowers are double-petaled, with about 5-23 petals, rose red, glossy; the number of flowers is large, flowering before leafing out, with the flowering period around December each year to early February of the following year. The fruit is nearly ovoid, and after maturing in April-May it becomes purplish black.

1.2 Geographical distribution and germplasm resources

The double-petaled winter cherry blossom is scattered across nine natural villages in Xiyi Town, Liuhe Township, Jindun Township, and Yunhe Town of Heqing County, with a total of 34535 plants, including 30500 seedlings, 3614 plants with a trunk diameter at breast height of 5-10 cm, 420 plants with a trunk diameter at breast height of 10-30 cm, and 2 plants with a trunk diameter at breast height of 45-63 cm; there are two century-old mother trees, distributed in Beideng Village of Xiyi Town and Wuxing Village of Liuhe Township. The seeds for propagation of the double-petaled winter cherry blossom all come from these two mother trees. Seizing the opportunity of Heqing's creation of a provincial-level garden county, the application and promotion of the double-petaled winter cherry blossom in landscaping was strengthened, and about 680 plants of the double-petaled winter cherry blossom were transplanted.

1.3 Ecological habits

It prefers cool, humid conditions and sunlight. The suitable growing-area climate conditions are an annual average temperature of 14°C-16°C, annual rainfall of 850-970 mm, and an altitude of 2200-2300 m. Fertile loam with good drainage is best for the soil. The flowering period, petal number, and annual average temperature, sunlight, nutrients, and tree vigor of the double-petaled winter cherry blossom are closely related. If the average temperature is high, the flowering period advances; if nutrients are sufficient and growth is strong, there are more flowers, more petals, and brighter flower color; otherwise, growth is poor, flowers are sparse, petals are fewer, and flower color becomes lighter. Due to uneven nutrient supply, double-petaled winter cherry blossoms on the same tree may have different petal numbers. Flowers that open earlier can have 15-23 petals, while those that open later may have only 5 petals.

1.4 Propagation methods

The double-petaled winter cherry blossom is usually propagated by seed. After the propagated seedlings grow up, observation during flowering shows that some seedlings undergo two kinds of variation: first, the number of petals decreases and the flower color becomes lighter, with the color between rose red and pink; second, the petals and flower color are directly consistent with the winter cherry blossom. This indicates that the seed genetic stability of the double-petaled winter cherry blossom is poor. In order to stabilize the ornamental characteristics of the double-petaled winter cherry blossom and facilitate its promotion and application in landscaping, it is recommended to propagate by grafting to ensure the ornamental value of the double-petaled winter cherry blossom.

1.5 Ornamental characteristics

1.5.1 Flowers

The flower is the most ornamental part of the double-petaled winter cherry blossom. Each flower has about 5-23 petals, is double-petaled, rose red, and the flowers gather in clouds. The flowering period is about December each year to early February of the following year. When the whole tree is in full bloom, it is like a rose-red rosy cloud, incomparably bright, very beautiful and spectacular. It is a brilliant scene in winter and gives people a warm feeling like spring. Therefore, locals commonly call it “little spring.”

1.5.2 Flowering period

The flowering period is what gives the double-petaled winter cherry blossom the greatest potential for garden application. The flowering period of the double-petaled winter cherry blossom is about 15-20 days later than that of the winter cherry blossom. It is the transitional period between the flowering periods of the winter cherry blossom and the Yunnan cherry blossom, can fill the gap between the flowering periods of the winter cherry blossom and the Yunnan cherry blossom, and can effectively improve the ornamental value of outdoor garden landscapes.

1.5.3 Leaves

The leaf color of the double-petaled winter cherry blossom is extremely rich. When the leaves first emerge, they are deep purplish red, then after spreading and maturing they become yellow-green, and in autumn they gradually turn yellow again. Therefore, the double-petaled winter cherry blossom is a typical tree species with obvious seasonal changes and both spring leaf color and autumn leaf color.

1.5.4 Fruit

After the flowers fade in mid-to-late February, the double-petaled winter cherry blossom enters the fruiting stage, and the fruit matures at the end of April and the beginning of May. The fruit is nearly ovoid and purplish black. The fruit goes from green at the beginning to purplish black at maturity, with many gradual color changes in between, which is also a unique landscape.

In short, the double-petaled winter cherry blossom is not only a treasure for winter flower viewing, but also a rare garden plant for viewing both fruit and leaves.

2 Garden application

Because of its bright flower color, unique petals, and rich leaf color, the double-petaled winter cherry blossom has broad application prospects in gardens. In landscaping, planting forms such as specimen planting, row planting, clump planting, and mass planting are mostly used.

2.1 Specimen planting

The double-petaled winter cherry blossom is a fast-growing tree species. The tree is tall and upright, with luxuriant branches and leaves and a vigorous posture. When flowering, the flowers are bright and abundant, and the seasonal changes in leaves are rich. It is a variety that blooms relatively rarely in winter. Therefore, whether planted as a specimen in a courtyard, workplace, or residential community, or planted as a specimen on a hillside, beside a lake, or by a stream, it can attract people's attention when flowering in winter and become the focal point of vision and the center of the landscape.

2.2 Row planting

In summer, the double-petaled winter cherry blossom has luxuriant branches and leaves and forms green shade; in winter, the whole tree is full of flowers, full of spring vitality. It has a high branching point, grows rapidly, and has strong stress resistance, making it very suitable as a street tree. At present, double-petaled winter cherry blossoms are planted on both sides of Zhaoxia Road and Gushan Road in Heqing. Because the flowering period is consistent, the flowers bloom at the same time in winter, forming a beautiful scene. When the flowers fall, the petals dance, and walking beneath them is like being in a fairyland. Because the double-petaled winter cherry blossom is relatively more precious than the winter cherry blossom, it is still uncommon to use it as a “cherry blossom road.” However, with the promotion and application of the double-petaled winter cherry blossom, it is believed that it will be widely used in urban street tree planting in the future.

2.3 Clump planting

In street green spaces and squares, the double-petaled winter cherry blossom can be planted in clumps of 2-5 plants, and can also be arranged with surrounding evergreen tree species such as camphor, cedar, and southern magnolia, fully allowing people to experience the beautiful scene of “a touch of red among green trees.”

2.4 Mass planting

[Jishan Huayao] In some theme parks, the double-petaled winter cherry blossom is mixed and mass-planted with other cherry blossom varieties that differ in flowering period, flower color, and petals. This can both extend the flowering period and maintain variety diversity. When the flowers bloom, they form clusters, layers, groups, and patches of brilliant cherry blossom scenery. Walking among them lets people experience the enjoyment of a beautiful scene like being in a sea of flowers. For example, Heqing Cherry Blossom Park uses 18 cherry blossom varieties, including the double-petaled winter cherry blossom, winter cherry blossom, Yunnan cherry blossom, Japanese early cherry, and late cherry, in a reasonable arrangement to create a cherry blossom theme park composed of Cherry Blossom Valley, Cherry Blossom Sea, and Hundred Cherry Garden. Cherry Blossom Park can fully reflect the group landscape ornamental effect of cherry blossoms, can also serve as a cherry blossom science education base, and at the same time can serve as a gene bank of double-petaled winter cherry blossom germplasm resources, creating good conditions for garden scientific research work.