Fragrant chrysanthemum belongs to Compositae and Millennium chrysanthemum, also known as white wormwood, jade hibiscus and hibiscus chrysanthemum. It is a perennial evergreen subshrub, which is widely cultivated in the middle and lower reaches of the Yangtze River, especially in Shanghai and Jiangsu. It is often used as potted plants or bonsai. It is suitable for cultivation and viewing on balconies, indoors and in courtyards. The leaves are gently touched with hands, and the aroma is like wormwood and wild chrysanthemum, which makes people cool, comfortable and refreshing.
Fragrant chrysanthemum has a plant height of 60 ~ 120 cm, leaves alternate, tightly clustered at the top of branches, narrow obovate wedge, 2 ~ 3 cm long and 0.3 ~ 0.5 cm wide, apex oval, leaf base wedge, no sawtooth, and leaves covered with silver gray pubescence. The head is nearly spherical, golden yellow, 4 ~ 5 mm in diameter, born in the upper leaf axil, and the flowering period is from August to September. Fragrant chrysanthemum looks like silver leaf chrysanthemum, but its leaves are delicate and fragrant. It is a specialty flower in Huai’an City, Jiangsu Province.
Fragrant chrysanthemum is native to central and southern China. It likes to be warm and humid. It grows at an appropriate temperature of 15 ~ 25 ℃ and is heat-resistant. It grows well at a high temperature of 35 ℃. It is relatively cold resistant, and the overwintering temperature is about 0 ℃. In the middle and lower reaches of the Yangtze River, it is appropriate to overwinter in a cold room, enter the house after frost, and leave the house from Qingming to Guyu. Xiangju enjoys a bright light. It grows in full day light in spring, autumn and winter, with a daily light of no less than 6 hours. Xiangju is a short sunshine plant, with a little shade in the hot sun and heat in summer. It should grow in loose, fertile and well drained sandy loam without strict requirements on soil pH, and grow well at pH 6 ~ 7.5. Like humidity and avoid waterlogging. Prevent and discharge waterlogging in rainy season to prevent waterlogging and root rot death. Fragrant chrysanthemum likes fertilizer. It should be thin and applied frequently during the growth period.
Germination began in early April, and the rapid growth period of new shoots was from early May to mid June. The high temperature growth was inhibited in summer and entered the secondary growth in autumn, but the growth was not as large as that in spring. The branches have strong sprouting force, can withstand pruning, and are soft and easy to shape.
(1) Upper basin
Fragrant chrysanthemum is generally planted with 2 ~ 3-year-old cutting seedlings, which should be purchased in March ~ April. If you want to propagate seedlings, you can buy seeds for spring sowing. The upper basin can be purple sand square basin, hexagonal basin or rectangular basin. The basin soil is prepared with garden soil, manure and sand according to 6:1:3, and the basin is put into use from late March to early April. Fill the bottom hole with green yarn. Fragrant chrysanthemum is afraid of ponding. A layer of coarse carbon residue or broken tiles should be placed at the bottom of the basin as the drainage layer, and rotten cake fertilizer or hoof pieces should be placed on it as the base fertilizer. After planting, it should be watered thoroughly, and then watered again the next day to make the root system close to the soil.
(2) Shaping and trimming
Potted fragrant chrysanthemum can be integrated into a natural back shape, cloud layered shape and recumbent shape. Generally, there are 3 ~ 4 main branches, which are divided into 3 ~ 4 layers. The lower layer is larger and the upper layer is smaller. The lowest branch can also be integrated into a relatively long floating branch, which hangs at the lower part of the basin surface. Plastic surgery should be carried out in March to April and August to September of the slow growth period. Fragrant chrysanthemum branches are thin and crisp. Plastic surgery should be careful and the force should not be too strong.
During the growth period, Xiangju should attach great importance to pruning and pinching, and timely remove dense branches, bare branches and Cross branches. In the first and middle of May, when the new shoots grow to 8 ~ 10 cm, leave 2 ~ 4 cm short cut, clean up the redundant branches between the branches and between the upper and lower layers, and then place them in a sunny place. After 10 ~ 20 days, the tender branches germinate again, and the new silver gray leaves are very beautiful. With the growth of new shoots, the old leaves at the base will gradually wither. The old leaves should be wiped off in time before germination and after short cutting. In the middle and late July, if the new shoots grow vigorously, they can be picked for 1 ~ 2 times.
(3) Fertilizer and water management
Fragrant chrysanthemum likes wet and fertilizer. The principle of fertilization should be thin first and then thick, small amount, frequent application and reasonable combination of nitrogen, phosphorus and potassium. In the growth period, the cake fertilizer and water shall be applied every 10 ~ 15 days. In the later stage of growth and post flowering fruiting period, the phosphorus and potassium fertilizer shall be applied, and 0.2% urea and 0.1% potassium dihydrogen phosphate can also be sprayed on the leaves. The use of organic fertilizer must be rotten. In high temperature weather, fertilizer should be stopped or a small amount of inorganic fertilizer should be applied. Potted fragrant chrysanthemum shall be changed every 2 years. Base fertilizer shall be applied in autumn or when changing pots. Generally, rotten cake fertilizer or stable manure shall be used, with 20 ~ 100g per pot.
The watering of fragrant chrysanthemum is relatively strict. It needs to be timely, timely, appropriate, dry and thoroughly watered. Water timely according to growth, temperature and humidity. Water once a day or the next day in spring and autumn, early and late in summer and 7 ~ 10 days in winter. Watering shall be timely, and wilting and dehydration shall not occur. The amount of watering should consider different growth and development stages and different climate changes. It should be watered appropriately. During the flowering period, it should maintain a certain humidity of the soil, which is conducive to seed setting and avoid heavy watering. Xiangju is most afraid of waterlogging. Before the rainy season, check the drainage hole of the flowerpot, and pour out the accumulated water in time after the rain. Never die from waterlogging and rotten roots.
(4) Pest control
Fragrant chrysanthemum has strong disease resistance and fewer diseases and insect pests. Common ones are leaf black spots or brown spots with white powder and aphids, red spider, scale insects and leaf eating pests. Timely inspection and control shall be carried out. Leaf spot disease can be controlled 800 ~ 1000 times with 50% carbendazim or 75% chlorothalonil, and powdery mildew can be controlled 1000 times with Triadimefon. The aphid of fragrant chrysanthemum is heavy. Once found, spray 1000 times of pyrazine in time. Scale insects are killed at 40% speed 1000 times and sprayed 2 ~ 3 times in may ~ July of larval stage. Red spider was controlled with 15% sweep mite net EC 2000 times.