How to grow Ageratum conyzoides? A detailed guide to its characteristics and cultivation methods
Ageratum conyzoides (blue mist flower, goatweed)
Scientific name: ageratum conyzoides
Aliases: goatweed. In Guangdong it is called salt shrimp flower, white grass flower, white-haired bitter, white-flowered stink grass; in Yunnan it is called Chongyang grass; in Guizhou it is called pus bubble grass and green shengma; in Guangxi it is called stink stove grass. In Baoshan, Yunnan it is also called water ding medicine.
Morphological characteristics: grown as a perennial but cultivated as an annual, 30-60 cm tall. The whole plant is covered with fine hairs; leaves are simple, opposite, ovate. The flower heads form tassel-like clusters; all the florets are tubular, in colors such as blue, pink and white.
Ecological habits: likes light, not cold-tolerant. Strong branching, tolerant of pruning.
Flowering period: July to October.
Flower meaning: good temper. It carries the meaning of "respect and love", and is the guardian flower of Scorpio and the birthday flower of those born on August 14.
Landscape uses: flower beds, ground cover, potted plants, flower borders, rock gardens.
Medicinal effects: the whole herb is used as medicine, with effects of clearing heat and detoxifying, and reducing inflammation and stopping bleeding.
Cultivation. It likes a warm environment with plenty of sunlight; growth is poor under high heat or when the soil is too wet. It is highly adaptable and can grow in all kinds of soil, but medium-fertility soil is best; rich soil or too much nitrogen fertilizer actually results in fewer flowers, and it tolerates relatively extensive management.
Propagation. Ageratum conyzoides is mainly propagated by seed. Sow in March, transplant the seedlings, and set them out in the open ground after the last frost; in warm areas they can be sown directly in the open ground. For cutting propagation, around End of Heat (late August), cut young stems of the current year, remove 2/3 of the leaves, then cut into sections of 3 axillary nodes each as cuttings; then put the cutting medium (clean yellow sand or rice husk ash) into a leaky wooden box, level the surface, make holes with a bamboo chopstick, and insert the cuttings, with the spacing such that the leaves do not overlap each other. After inserting, water thoroughly with a fine-spout watering can, cover with plastic film to keep in moisture, and place under a shade shed. After the sun sets, the film can be uncovered for ventilation and to catch the night dew. Water once in the morning, then cover with the film again. After about 10 days, the cuttings will have rooted, and the film is no longer needed. The seedling box can gradually be moved into the sunlight so the young plants get hardened off by the sun. Because photosynthesis increases, the axillary buds of the young plants will grow faster. After about 20 days they can be transplanted into pots and enter normal care. By the end of October, pinch once to widen the plant's spread and increase the number of flowering branches. When the outdoor temperature drops to 10°C, move them indoors to a spot with light in good time. By February of the following year, small flower buds can be seen at the top of the plants, and by about the end of March or early April you can enjoy the flowers of Ageratum conyzoides.
Uses: an ideal flower bed material. It can also be used for flower borders, forest edges, flower-studded lawns and ground cover.
Pest and disease control of Ageratum conyzoides. Cultivation methods of Ageratum conyzoides
Ageratum conyzoides mainly suffers from three major pests and diseases: root rot, rust, and damage from noctuid moths and whiteflies. Below, the editor will explain in detail the pest and disease control of Ageratum conyzoides, its cultivation methods and related knowledge. Let's take a look together.
Pest and disease control of Ageratum conyzoides
Ageratum conyzoides often suffers from root rot, rust, and damage from noctuid moths and whiteflies.
Control methods: for root rot, spray with a 1000-fold dilution of 10% antibacterial agent 401 acetic acid solution; for rust, spray with a 2000-fold dilution of 50% carboxin wettable powder.
Planting Ageratum conyzoides in fields can control mite pests. In orchards such as Xiangtian and Gaohu, 500 mu of Ageratum conyzoides was introduced; making use of its long flowering period, it can provide abundant pollen as food for the predatory mite Amblyseius, a natural enemy of pest mites, thereby greatly multiplying the natural enemy and controlling mite damage. Amblyseius is an important natural enemy of the red spider mite, yellow spider mite and rust mite of ponkan, and can prey on the eggs and all stages of pest mites. Mites are the main pests in ponkan orchards; when the temperature is suitable, they can reproduce 14-18 generations per year, causing severe damage and being very difficult to wipe out completely, often forcing fruit growers to use large amounts of chemical pesticides, which not only causes pollution of fruit and the environment but also achieves very little. Planting Ageratum conyzoides in ponkan orchards to multiply Amblyseius can effectively control pest mite damage, thereby greatly reducing pesticide use, saving labor, lowering costs, improving quality, ensuring the hygiene and food safety of the fruit, and increasing the economic income of fruit growers.
Introduction to Ageratum conyzoides
Ageratum conyzoides, also known as goatweed, belongs to the genus Ageratum in the Asteraceae family. It is native to Mexico. It is distributed from low altitudes up to areas of 2800 m. In China's Guangdong, Guangxi, Yunnan, Guizhou, Sichuan, Jiangxi, Fujian and other places, it is cultivated and also has naturalized wild distribution; it grows in mountain valleys, under forests or at forest edges on hillsides, by rivers or on hillside grasslands, at field edges or on wasteland. In Zhejiang and Hebei it is only seen in cultivation.
I. Morphological characteristics
Root and stem: Ageratum conyzoides is an annual herb, 50-100 cm tall, sometimes less than 10 cm. It has no obvious main root. The stem is stout, 4 mm in diameter at the base, or rarely slender with a base diameter of less than 1 mm, unbranched or branching from the base or from the middle upward, or the lower base prostrate with adventitious roots often growing at the nodes. All stems and branches are reddish, or the upper part green, covered with white powdery short soft hairs, or the upper part covered with dense spreading long villi.
Leaves: the leaves of Ageratum conyzoides are opposite, sometimes alternate in the upper part, often with axillary undeveloped leaf buds. The middle stem leaves are ovate or elliptic or oblong, 3-8 cm long and 2-5 cm wide; from the middle leaves upward and downward and on the leaves of axillary branchlets they gradually become smaller or small, ovate or oblong; sometimes all the leaves of the plant are small, only 1 cm long and only 0.6 mm wide. All leaves are obtuse or broadly cuneate at the base, with three basal veins or indistinct five veins, acute at the apex, with rounded serrations at the margin, and with petioles 1-3 cm long; both surfaces are covered with sparse white short soft hairs and have yellow glandular dots; the hairs along the veins on the upper surface and on the lower surface are slightly more numerous, sometimes nearly hairless below; the petioles of the upper leaves or of the axillary young branches and the small leaves on axillary branches are usually covered with dense white spreading long villi.
Flowers: Ageratum conyzoides has 4-18 flower heads arranged at the top of the stem in usually dense corymbose inflorescences; the inflorescence is 1.5-3 cm in diameter, rarely arranged in loose corymbose form. The pedicel is 0.5-1.5 cm long, covered with powdery short soft hairs. The involucre is bell-shaped or hemispherical, 5 mm wide. The involucral bracts are in 2 layers, oblong or lanceolate-oblong, 3-4 mm long, hairless outside, with torn margins. The corolla is 1.5-2.5 mm long, hairless outside or with powdery fine soft hairs at the tip, with a 5-lobed limb, light purple.
Fruit: the achene of Ageratum conyzoides is dark brown, 5-ribbed, 1.2-1.7 mm long, with sparse white fine soft hairs. The pappus scales are 5 or 6, oblong, abruptly or gradually narrowed at the apex into a long or short awn-like tip, or some scales are truncate at the apex without an awn-like tapering tip; all pappus scales are 1.5-3 mm long.
The flowering and fruiting period of Ageratum conyzoides is year-round.
II. Ecological habits
Ageratum conyzoides likes warmth and a sunlight-rich environment. It is not strict about soil. It is not cold-tolerant, and grows poorly under extreme heat. It has strong branching ability and tolerates pruning.
Cultivation methods of Ageratum conyzoides
1. Planting out
When the Ageratum conyzoides seedlings have 2-4 branches, plant them out into pots. Use one plant per 4-inch flower pot; the potting soil should be 1/3 farmyard manure, 1/3 garden soil and 1/3 fine sand, mixed and sieved. After planting the young seedlings, firm the potting soil, water thoroughly, and place in a cool spot; after 7-10 days move to a sunny spot. At this point they have basically recovered from transplanting and begin normal growth. Pay attention to water and fertilizer management: water when the surface layer of the potting soil turns white and looks dry, and each watering should be thorough, not a half watering. In the high-temperature season, the peak growth period of the plants, water twice a day. Apply dilute cake fertilizer water once every 10-15 days, and appropriately increase the application of phosphorus and potassium fertilizers. This can make the plants shorter, with more flowers and brighter colors, improving their ornamental value.
2. Pruning
Ageratum conyzoides has a long flowering period; to keep the plant short and compact, with many flowers and good looks, it must be pinched back several times, generally 3-4 times. To form a rounded plant shape with flower buds forming at the top of every branch and blooming at the same time, making the branches and leaves lush and the flowers numerous and colorful.
After the first batch of flowers has finished, prune and trim in good time; generally keep the old branches 5-6 cm high and cut off the upper part, and at the same time thin out overly dense branches. Then ensure sufficient water and fertilizer to promote the sprouting of new branches, so that the leaves are green and the flowers fresh.
3. Humidity
It likes a humid or semi-dry climate environment, and requires the relative air humidity of the growing environment to be 50-70%; when the relative air humidity is too low, the lower leaves turn yellow and fall off, and the upper leaves lose their luster.
4. Temperature
Because it originates from subtropical regions, it has strict requirements for winter temperature; when the ambient temperature is below 8°C it stops growing. It has strong adaptability to light. When keeping it indoors, place it in a place with bright light as much as possible, such as a well-lit living room, bedroom or study. After keeping it indoors for a period (about one month), move it outdoors to a shaded place (with insulation conditions in winter) for a period (about one month), and alternate back and forth like this.
5. Management
Ageratum conyzoides is not cold-tolerant; before frost arrives, move it indoors to a sunny place, where the nighttime temperature should be above 5°C and the daytime temperature 10°C-15°C for normal growth and flowering. Water once every 3-5 days, and apply dilute cake fertilizer water once every half month.
Propagation methods of Ageratum conyzoides
1. Seed propagation
Ageratum conyzoides seeds are tiny, so sowing requires meticulous work. Generally, sow in a greenhouse in early February, or sow in the open ground in early April. The growing soil should be half farmyard manure and half garden soil, mixed with a small amount of leaf mold, mixed evenly and then sieved. For small-scale seedling raising, flower pots can be used (for large-scale seedling raising, beds can be made); put the growing soil into the pot, firm it, water thoroughly, and after the water seeps down, evenly broadcast the seeds on the wet soil. The covering soil must not be too thick, just enough to cover the seeds. Keep the potting soil moist. Seedlings emerge in about 10 days. When the seedlings have 2 pairs of true leaves, prick them out into small plastic nutrient pots, one plant per pot. Ageratum conyzoides seeds are small, and the young seedlings grow slowly.
2. Cutting propagation
To achieve early shaping and early flowering, cutting propagation can be used. For cutting propagation, prepare large mother plants and keep them in a greenhouse in winter; in early spring take healthy branches, keep 2-4 true leaves, and do not keep the growing point. The branch length is 5-6 cm, the cut should be below a node, and insert immediately after cutting. The insertion depth is 1/3-1/2 of the cutting length. In the high-temperature season, place in a cool spot after inserting to prevent high temperature and sun exposure. Roots form in about 10 days, and the seedlings can be separated. Apart from the low temperatures of winter, cutting propagation can be carried out in other growing seasons and roots easily.
Key care points for Ageratum conyzoides
1. Cultivating strong seedlings
Ageratum conyzoides seeds are tiny, so sowing requires meticulous work. Generally, sow in a greenhouse in early February, or sow in the open ground in early April. The growing soil should be half farmyard manure and half garden soil, mixed with a small amount of leaf mold, mixed evenly and then sieved. For small-scale seedling raising, flower pots can be used (for large-scale seedling raising, beds can be made); put the growing soil into the pot, firm it, water thoroughly, and after the water seeps down, evenly broadcast the seeds on the wet soil. The covering soil must not be too thick, just enough to cover the seeds.
Keep the potting soil moist. Seedlings emerge in about 10 days. When the seedlings have 2 pairs of true leaves, prick them out into small plastic nutrient pots, one plant per pot. Ageratum conyzoides seeds are small, and the young seedlings grow slowly. To achieve early shaping and early flowering, cutting propagation can be used. For cutting propagation, prepare large mother plants and keep them in a greenhouse in winter; in early spring take healthy branches, keep 2-4 true leaves, and do not keep the growing point. The branch length is 5-6 cm, the cut should be below a node, and insert immediately after cutting. The insertion depth is 1/3-1/2 of the cutting length. In the high-temperature season, place in a cool spot after inserting to prevent high temperature and sun exposure. Roots form in about 10 days, and the seedlings can be separated. Apart from the low temperatures of winter, cutting propagation can be carried out in other growing seasons and roots easily.
2. Planting out and management
When the Ageratum conyzoides seedlings have 2-4 branches, plant them out into pots. Use one plant per 4-inch flower pot; the potting soil should be 1/3 farmyard manure, 1/3 garden soil and 1/3 fine sand, mixed and sieved. After planting the young seedlings, firm the potting soil, water thoroughly, and place in a cool spot; after 7-10 days move to a sunny spot. At this point they have basically recovered from transplanting and begin normal growth. Pay attention to water and fertilizer management: water when the surface layer of the potting soil turns white and looks dry, and each watering should be thorough, not a half watering. In the high-temperature season, the peak growth period of the plants, water twice a day. Apply dilute cake fertilizer water once every 10-15 days, and appropriately increase the application of phosphorus and potassium fertilizers. This can make the plants shorter, with more flowers and brighter colors, improving their ornamental value.
3. Plant pruning
Ageratum conyzoides has a long flowering period; to keep the plant short and compact, with many flowers and good looks, it must be pinched back several times, generally 3-4 times. To form a rounded plant shape with flower buds forming at the top of every branch and blooming at the same time, making the branches and leaves lush, the flowers numerous and colorful, beautiful and spectacular. After the first batch of flowers has finished, prune and trim in good time; generally keep the old branches 5-6 cm high and cut off the upper part, and at the same time thin out overly dense branches. Then ensure sufficient water and fertilizer to promote the sprouting of new branches, so that the leaves are green and the flowers fresh.
4. Winter management
Ageratum conyzoides is not cold-tolerant; before frost arrives, move it indoors to a sunny place, where the nighttime temperature should be above 5°C and the daytime temperature 10°C-15°C for normal growth and flowering. Water once every 3-5 days, and apply dilute cake fertilizer water once every half month.
Related knowledge about Ageratum conyzoides
1. Variety classification
Commonly cultivated varieties of Ageratum conyzoides include "Blue Danube": a dwarf variety, plant height 15-18 cm, flowers blue-purple. The "Hawaii" series: stems and leaves dense and neat, plant height 15 cm, flowers in colors from deep blue to red, pure white, etc. The "Pacific" series: plant height 20 cm, flowers deep blue-purple. "Pink Variation": plant height 15-20 cm, flowers pink.
2. Genus overview
Ageratum conyzoides is native to Mexico and is now widely distributed in the tropical regions of the Eastern Hemisphere. It was first recorded in China in G. Bentham's (1861) "Flora of Hong Kong", and was found in southern Yunnan at the end of the 19th century. It is now commonly distributed in the low mountains, hills and plains of the Yangtze River basin and areas to the south. Another species originating from Central America, Ageratum houstonianum, has been introduced and cultivated in southern China as an ornamental and often escapes as a weed.
Annual herb, growing below 2800 m altitude in fields, wasteland, hillside grasslands, valley thickets and other places. It has a high seed-setting rate and fast reproduction. Ageratum conyzoides mainly has three color lines: blue, white and violet-purple; the plant can grow to 20-25 cm tall. It is best used as a potted plant and a bordering plant in courtyards, or to accent rock gardens, or as an indoor ornamental. If applied on a large scale in flower beds as a base color arrangement, it also has a unique effect.
Ageratum conyzoides is a perennial herb of the genus Ageratum in the Asteraceae family, a biennial or perennial herb, with about 7000 seeds per gram. At a temperature of 26-29°C, this species germinates 7-10 days after sowing, and during the germination period it should be placed in sunlight. The flowers are small, and the flower heads are densely borne at the top of the branches. It tolerates pruning and can bloom again after cutting. It is mostly propagated by seed, but can also be propagated by cuttings. After sowing, it can be transplanted in 15-20 days and can bloom in about 13 weeks; in southern regions it can bloom in 11-12 weeks.
3. Functions and uses
Potted Ageratum conyzoides is used to decorate windowsills, balconies or roof gardens, simple and elegant yet eye-catching.
Ageratum conyzoides planted in the ground is used in flower beds, flower strips, planting troughs and lawn edges, with clear and bright landscape layers. Dotting small courtyards and roadsides, it is natural and elegant, heightening the feeling of spring.