[Morphological characteristics]
Deciduous shrub with alternate leaves and serrated edges, some of which are lobed or entire. Flowers are bisexual, occasionally bisexual. Racemes, usually umbrella-shaped, also have corymbs or panicles. Petals are usually slightly longer than sepals. More than 50 kinds of cake fruits are native to China, many of which are widely planted in gardens. Common ones are:
Smiling flower S.prunifolia deciduous shrub with slender and slightly inclined branchlets. Leaves ovate to oblong-lanceolate, veins pinnate. Umbrella, without peduncle, with 3-6 flowers and several leaflets at the base. Pedicel length 0.6- 1 cm, double flower, diameter 1 cm. They are white and bloom from March to May.
Guangzhou hydrangea, also known as hemp leaf hydrangea, is characterized by many flowers, small deciduous shrubs, clumps and branches. Branchlets are dark red, sometimes peeling off. Leaves rhombic-lanceolate to rhombic-elliptic, with notched serrations near and above the middle. The flowers are white, with 10 ~ 30 integrated hemispherical umbels (see color map 108), which bloom with leaves from April to May, and the follicles stand upright. It has strong adaptability and easy cultivation, and is widely used in urban gardens.
S.thunbergii, also known as pearl flower, has strip-shaped leaves with sharp serrations from the middle and upper parts, corymbose inflorescence without a stalk and 3-7 white flowers.
Spiraea China has reddish-brown branchlets, rhombic to obovate leaves and white flowers, and the flowering period is from May to autumn.
Spiraea farinosa, also known as Spiraea japonica, has elliptic to broadly lanceolate leaves. Pink or red flowers, corymbose inflorescences, planted at the top of new branches of the year, gradually extended to early September after flowering in late May. It is produced in Japan and cultivated all over China (see color map 109).
[distribution]
Spiraea is widely distributed in Hebei and Liaoning in the north, Guangdong in the south, Shaanxi and Gansu in the west and Taiwan Province Province in the east. It is cultivated in Japan and Korea.
[habit]
Spiraea is a subtropical and temperate tree species with strong cold tolerance and lives in warm, sunny and humid places. Strong adaptability, poor soil can also grow. However, in places with good drainage and fertile soil, it grows luxuriantly, has strong tillering ability, is easy to divide plants and propagate, has strong germination ability and is resistant to shaping and pruning.
[Propagation, Cultivation and Maintenance]
Spiraea has strong adaptability and extensive cultivation. Commonly used cutting, plant division, sowing and propagation. In the middle and late February, the dormant branches were cut off, and the middle and lower parts of 1 annual stout branches were selected, which were 10 ~ 12 cm long, and inserted into the soil for 2/3, and then the soil was often kept moist, and covered with curtains for shade in April. The cutting of semi-mature branches is carried out in the middle and late June. Take semi-lignified strong branches, leave 2 ~ 3 leaves at the upper end, insert them into the soil 1/2, water them fully, and then build a shed for shade. Plant division is carried out in February-March, and sprout strips can be separated from the mother plant in combination with transplantation, and then planted separately after proper pruning. It can also cultivate fertile soil, promote the mother plant to sprout more tillers, and dig and plant in the next year. Sowing, harvesting and secret storage for the winter will be carried out in March of the following year.
Transplanting is carried out at defoliation stage, and seedlings usually need to bring lodging soil, and large seedlings need to bring soil balls. Light pruning should be carried out after flowering, and branches that are too dense should be properly thinned. When the plants are weak, they can be re-pruned during dormancy, and sufficient base fertilizer can be applied for renewal.
The main pests and diseases are: hemp leaf rust ball brown spot, powdery mildew, scale insects, brontispa longissima, Spiraea aphids and so on. Prevention and treatment methods: ① Remove diseased leaves and burn them. Spraying pesticides such as carbendazim on leaf diseases and triadimefon on powdery mildew. (3) Spraying omethoate, dichlorvos, phosphoramidite and other chemicals on nymphs and aphids.
[Appreciation and Application]
Spiraea is an excellent ornamental shrub with lush flowers in Ye Qingqing. Planting in Chi Pan, slopes, roadsides, cliffs or the edge of trees is quite elegant and interesting. It is also very suitable if it is planted in front of lawns and houses for basic cultivation.