The cultivation of chrysanthemums

How to grow chrysanthemums


Characteristics of chrysanthemums

The genus "Chrysanthemum" includes some 37 species of plants from eastern Asia. They belong to the family of Compositae.

Wild chrysanthemums are perennial herbs or shrubs up to five feet tall.

Their leaves are lanceolate, lobed and very fragrant.

Their large flowers, like those of daisies, can be white, pink or yellow. They appear in the fall.

History of chrysanthemus

Chrysanthemum cultivation began in China about 2500 years. It arrived in Europe in the seventeenth century, where it was named Chrysanthemum, from the Greek word "krysous = gold" and "anthemon = flower." It is called so because most primitive flowers had this color.

Commonly, they are also called mums or chrysanths

In the nineteenth century their cultivation expands in in Europe. Numerous varieties are currently grown in many countries. In hot countries, they are cultivated outdoors, but in colder countries they are used as a cut flower, usually grown in greenhouses.

Cultivated crhysanthemums

Photo of chrysanthemums

The cultivated specimens have grown much larger flowers than the wild ones, many with floral heads single, double, semi-double or a ball and a wider range of colors that wild species from which they come. (White, yellow, pink, red, gold, purple, pale violet, etc. Almost all colors except blue). Those sold in florist's can have flowers during the whole year because they are forced to bloom. Otherwise, chrysanthemums bloom from autumn to early winter.

They can be forced to advance flowering by means of covering them, so that they receive less hours of light. This will mimic the natural cycle. Keep in mind that this plant blooms in the fall, when the day is short, there is not much light and the night is very long.

Although many of chrysanthemums are perennial, they are usually grown as annuals indoors, so that once flourished, they must be discarded. Grown outdoors, they can be grown as perennial shrubs in large containers or directly into the soil, reaching up to 1 meter in height. When grown in small pots, they usually grow no more than about 40 cm.A chrysanthemum is the flower that forms the national emblem of Japan.

Chrysanthemum. Irrigation

Chrysanthemums always need to have a moist substrate. However, we must prevent them to become swamped which would result in root rot and fungus growth. When dry, they lose the flowers and it is very difficult to re-bloom them again.

In summer and very dry climates, one should monitor that they always maintain the necessary humidity. The best way to irrigate them during summer is to enter the pot in a container with water until the soil is well soaked. Subsequently, we will place it on a plate and let it drain well. We must be careful to empty the dish under the pot completely, so that no water remains below the pot.

When grown indoors, in warm weather and low humidity, or in winter when heating is on, we should spray it. We will use warm soften water or, if possible, rainwater.

Grown outdoors in large containers or in the ground, they do not need watering unless they are subjected to a period of drought.

Chrysanthemum. Uses

Photo of chrysanthemum

They are mainly used as garden flowers or as cut flowers. Grown as annuals indoors.

Chrysanthemum. Environment and exposure

Chrysanthemums prefer mild climates with average temperatures between 16 and 18 º C. They can hold up night temperatures up to 7 º C. Frosting spoils them, although they may re-sprout after frost. Under 7 ° C leaves turn yellow.

Grown indoors, they should be located in a bright, well ventilated place but out of drafts. If light is poor, flower buds do not open and flowers that are already opened quickly wither and fall.

By late spring, it is better to move them outdoors until late September. Thus the flowering lasts longer.

When grown outdoors, they can be sited in direct sunlight in areas of mild climate. However, we must bear in mind that sunlight should not be too strong in order no to burn the leaves.

In mild weather locations, placing them directly at the sun will provide a lasting flowering. In warmer sites, place them in a place with lots of light. Direct sunlight, especially facing south, can cause damage.

Some of them, such as Chrysanthemum indicum, do not tolerate shade. Others, such as Chrysanthemum tricolor, can be grown in semi-shade.

Photo of chrysanthemum

Chrysanthemum. Reproduction and care

Chrysanthemums can be reproduced from seeds sown directly in its final location. Germination takes place after 10 or 20 days, holding an average temperature of 15 ° C. In warmer weather locations, they can be sown in the fall.

Chrysanthemums can also be reproduced by cuttings during the month of March. To do this, cut healthy green stem cuttings about 6 or 7 cm in length. Remove the lower leaves, introduce them for some time in growth hormones, and plant them in a bed made with sand and peat. Water thoroughly and let them to root while maintaining a constant temperature of 15 ° C. The transplant has to be carried out from mid to late spring. Flowering occurs in mid to late autumn.

Keep in mind that only those plants propagated by cuttings that are grown outdoors usually bloom. For indoor cultivation one should use seeds or, better, buy specimens grown in gardens with flowers or about to bloom.

What mums should we choose?

We will choose healthy individuals, those that contain some flowers already open and the flower buds about to bloom. This is easily distinguished because you can already see the future colors of the petals at the buttons.

How to get abundant flowering?

In addition to the conditions of watering and adequate light, viewed above, they can produce a more abundant flowering if you pinch the ends of the young shoots in spring or cut some flowers when the plant has flowered.

The technique of pinching, besides stimulating flowering, can mold the shape of the plant causing it to grow more rounded and uniform, less gangly and awkward. To do this, remove the terminal bud of the stem "pinching " it with the thumb nail pressing on your index finger. In this way the plant ceases to grow vertically and does so across from new buds that arise on the sides of the pinched stem.

Cut flowers are very useful for interior decoration. They provide a good aroma and they are very long lasting.

It is recommended to cut all the stems of the plant after flowering, leaving only a few inches from the ground. By spring, it produces new shoots that will result in a plant with lots of energy, more uniform and abundant flowering in autumn and winter.

Chrysanthemum. Soil and fertilization

Chrysanthemums prefer slightly acidic soils with a pH between 5.5 and 6.5. They need to have a good drainage to prevent waterlogging. They require a good level of nitrogen and potassium.

Grown indoors, it is only necessary to apply universal garden fertilizers. While blooming, they must be fertilized every 2 weeks.

Chrysanthemum. Pests and diseases

The main pests that affect them are:

  • Mealybugs: They are insects that stick to plants, especially to the young shoots. They live off them because they have a few organs that are responsible for sucking the sap extracted from plants. Among the most important ones, we have those that excrete a kind of fluffy white substance resembling cotton.

They especially attack indoor plants, because the environmental conditions there (dry environment) favor its development. Among the affected plants, we have ficus, yuccas, oleander, or chrysanthemums.

To remove them we have to take all of them out with the help of piece of cloth soaked in alcohol. Afterwards, we will apply a systemic insecticide and separate the fouled plants from the rest of plants to prevent them to become contamination.

  • Trips: These are sucking insects that produce lesions on the leaves by sucking the sap with their beaks. The treatment is based on the elimination of infected stems and the use of an appropriate insecticide.

  • Ticks: They are mites that attack the plants when the atmosphere is warm and dry. Among the main ones we can point out the spider mites, some red insects, that, when accumulated, provide a reddish or brown layer to the underside of the leaves and a spider'slike web between the ribs on the underside.

If this attack progresses, they finally will make leaves to fall. All plants can be virtually affected, including either garden plants such as roses, hydrangeas, chrysanthemums and lilacs, or fruit trees.

The best way to control them is to apply mineral oil in winter, although it is also suitable to use a liquid insecticide in spring and summer combined with a thorough watering and spraying of the leaves with water to increase humidity. If we want to remove them with biological means, we can use other insects such as ladybugs that feed on them.

  • American serpentine leaf miner = chrysanthemum leaf miner (Liriomyza trifolii) mainly affects the leaves where which the larva excavates galleries that end up drying them. You must use a suitable insecticide to kill them.

  • Bud and leaf nematode of Chrysanthemum (Aphelencoides ritzemabosi) It is a worm that attacks chrysanthemums and other plants of the same family (Compositae). Unlike other nematodes, it does not attack the roots but the leaves, buds and twigs. The larvae feed on plant tissue creating galleries in the leaves while they excrete products that are toxic to the plant tissues.

In principle, the only damage is manifested by small yellow spots between the veins of the lower leaves. Over time, the leaves are completely brown and fall back as the infection is also affecting the upper leaves. Other times, the leaves grow from infected buds appear smaller and twisted. They can also present brown lesions on the petioles. Sometimes, some young stems turn brown and stop growing.

The treatment involves the removal of all infected material and the application of appropriate insecticides. As prevention methods, we recommend to disinfect the tools; do not use sprinkler watering as the worms need to move through humidity; space the plants to promote aeration, or cover the soil with a thick padding to stop its progress.

The main diseases affecting chrysanthemums are:

  • Powdery mildew (Oidium spp): These are fungi that produce white spots on leaves or buds. This requires the affected leaves to be quickly eliminated and a specific antifungal treatment to be applied. Overwatering favors its development, so it is recommended not to water while the soil moisture remains adequate. It is also advised not to wet the leaves.

  • Botrytis = gray mold (Botrytis cinerea): This caused by the fungus Botrytis cinerea. It produces flowers with brown papyraceous spots that sometimes can affect the leaves. Is mainly due to a lack of ventilation and excess of moisture as a result of having the plants too close together and spraying the leaves and flowers with water. Treatment should be based on removing the material in question and applying a general fungicide. Avoid to spray the flowers when watering.

  • Common rust (Puccinia chrysanthemi): This is another disease caused by fungus (Puccinia spp.) It causes reddish or brownish spots on leaves. This occurs when the temperature is very high. Treatment includes removing the affected leaves.

  • Other diseases that may affect chrysanthemums are the alternaria leaf spot (Alternaria sp.) Chrysanthemum aspermy cucumovirus (CAV), chrysanthemum mosaic virus Q (ChMV) or Chrysanthemum B carlavirus (CVB)

Other fairly common problems with chrysanthemums are:

  • Lack of flowering, probably due to a lack of watering or light. Cut the plant to separate and place it to the light, not to the direct sun. The plant will spring up and produce new flowers.

Sometimes there are not flowers because it is not the right time for chrysanthemums to blooms. (Just wait for the arrival of fall)

  • Dry leaves: Because of lack of watering or too cold weather. Water them properly or provide a warmer place.

  • Smaller leaves than normal: Because of too much or too little irrigation, lack of nitrogen, worms or viruses.

  • Gangly and awkward plants: This is due to an abnormal growth when chrysanths are cultivated in a too dark place. (Search for a clear spot). Other times they may show a lack of pinching (Pinch the tips of the stems as it was explained above)

punto rojo More information on chrysanthemums in the listing above.

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Botanical-online is an informative page that describes, among other topics, the traditional uses of plants from a therapeutic point of view. Their descriptions do not replace professional advice. Botanical-online is not responsible for self-medication and recommends consulting with the physician.