Wild Cosmos (Ulam raja): Description and benefits

Wild cosmos (Cosmos caudatus) of the family Asteraceae is related to the popular garden plant Cosmos. The common name of this plant is Ulam raja or king of salad. It is an annual herb growing about 1-8 ft tall having a sparsely hairy appearance. Originate in Latin America and is grown all over the South East Asia (1). This plant attains a maximum height of 3 m and bears pink or purple flowers.

This plant is very popular in Southeast Asia with its unique taste. Ulma raja is a bushy plant and can be eaten raw mainly the leaves of this plant are used as a flavored side dish in many of the popular cuisines of Southeast Asia (2). Another traditional benefit of this plant is it helps in improving blood circulation. Research studies reported that this plant is rich in antioxidants and other bioactive compounds like ascorbic acid, quercetin, and chlorogenic acid (3).

Traditional use of Wild Cosmos (Ulam raja)

In many cultures, this plant Cosmos caudatus is used for many beneficial effects like regulating blood pressure, and blood glucose and for healthy bone and as an anti-inflammatory agent.

Botanical description

Wild Cosmos (Ulam raja) are perennial herbs with ornamental flowers. The leaves stalks are 1-7 cm long with 10-20 cm long leaves which are dissected. the flowers are born on 10-30 cm long stalks and the petals of flowers are rose pink to purple. The flowers are compound in nature and are composed of 8 purple or red, petal-like ray florets and many yellowish-green disk florets in the center (4). These plants have a simple base with top branching.

How to grow Wild Cosmos (Ulam raja)

Growing wild cosmos or ulma raja is relatively easy. They are annual plants and propagate via seed germination. The germination is simple and can be done during the spring season. Simply seeds can tolerate all ranges of soil and just make sure the soil bed is moist for germination. do not over-mortize the soil bed as it may cause the seed rot.

After developing more than 4 leaves the seedlings should be transferred to the pots having a minimum distance of 15 cm between two plants (5).

How to take care of Cosmos(Ulam raja)


Cosmos (Ulam raja) is a perennial plant with a tropical and sub-tropical nature. Thus needs good sunlight and open space with moderate watering.


The plants are wild and hence need full sun for nearly 4 hrs or partial indirect sunlight for nearly 5-6 hrs. Too much sunlight may cause a lower number of leaves.


Moderate watering as too much watering may cause root rot. Hence make sure before watering that the top soil is completely dried off.


Generally, the plant Ulam raja does not require fertilizer and after flowering the plant generally dries and new plants will come from the seeds.


Aphids, Miley bugs, spider mites, and white flies are the common issues or pests that attack the plant. Regular pruning is the solution to manage these issues.

Other issues

Other issues are as wilting or sunstroke may affect the plant. Make sure that during summer time water the plant regularly and support the base of the plant with mulch to maintain the moisture level (5).

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