Cosmos (Cosmos caudatus)


Cosmos, wild cosmos or Ulam Raja, Cosmos caudatus, is an incredibly productive edible/medicinal plant. This plant is an annual, but can be regularly managed as a short-lived perennial. The leaves are eaten for their high mineral and antioxidant content, which is believed to contribute to increased blood circulation, bone strength and general good health. Wild cosmos creates a lot of biomass and can reach up to nine feet tall by about four feet wide. The plant starts off slowly, growing to a height of about two feet in the first few weeks, and then takes off to become the giant it wants to be. They usually don’t start flowering until they are four to five feet tall and flower continually until their death.


Wild cosmos is grown from its prolific seeds. Seeds are sown at the soil surface. However, they will sprout through fine textured mulch as well.


This plant is carefree. Sprinkle around seeds, wait and watch them grow. Their lifecycle seems to be about nine months if left unchecked. To prolong their life, I usually allow them to seed heavily for a little while, collect all the seeds and then cut the plant back to waist height. This will spark them to regrow vigorously, again; this process can be done continuously.


The tender young leaves and stems are commonly eaten raw. Eat from a plant that has not yet flowered as the flavor becomes more intense after flowering. If managed by regularly pruning off flower stalks, the plant will continue to grow leafy material suitable for consumption.

Where to obtain planting materials

Ask a friend for some seeds. I’ve never seen this plant for sale, and I only recently discovered that it’s edible, and what its scientific name is.

My Garden

Wild cosmos is one of my staple biomass-creating plants in my systems. I typically create successional cover crop mixes creating a continuous blanket of biomass to protect soils and to create living mulch to cut and feed to my other cropped plants. Where I have it growing as a hedge, it helps with weed suppression, by shading and preventing germination of less desirable seedlings. Cosmos flowers attract lots of bees and other pollinators!

Happy Gardening!



21 thoughts on “Cosmos (Cosmos caudatus)

  1. Spencer,
    I enjoy your website. Cosmos is something I grow here on the mainland. Mine might reach 3-4 feet and not nearly so bushy. I haven’t attempted to eat before but will give them a try.
    I look forward to seeing your progress again soon. Keep Julie smiling!

      • hallo i am munich germany i want to the f Cosmos Caudatus (Ulam Raja )seeds and have them send to me germany your help will be super thanks

      • @Tropical Self Sufficiency ; Sorry I just read your message today 5/15/22.
        I would love that if you can send me some! Thank you for your offer.
        I am in the US.

    • Dear Suzie,Good day to you.May I know where are you from?If within Malaysia.then I can mail to you some freshly collected Cosmos CAUDATUS for free.FYI,I have many matured plants on the ground n also quite a number in flower pots.
      Hope to hear from you soon

      • Hello Goh Hua Kuang,
        Unfortunately I’m not in Malaysia. I’m in the Bay Area, California. I want very much to grow this and am trying to find sources of seeds or plants that I an buy.

      • hallo i am from munich germany i want to the f Cosmos Caudatus (Ulam Raja )seeds and have them send to me germany your help will be super thanks

      • Goh Hua Kuang; Sorry I just read your message today 5/15/22. Thank you for your offer I would love that! I am in the US though. Good day to you!

      • Hi Mr.Goh,
        A very good day to you.
        Would you still have the seeds/plant cuttings?
        I would very much like to plant some Raja Ulam in my garden.
        Located in KL. Hoping to hear from you soon! 🙂

      • Hello, I’m Molly and just came across this thread.
        I’m just now discovering the wonders of cosmos caudatus. I too want to buy seeds to grow them. I live in the Bay Area, California. Please let me know if you will sell seeds to me. Thank you and Regards,

      • Hello, I’m Molly from the Bay Area, California. I’m desperately trying to find cosmos caudatus seeds or plants . Can i buy from you or do uou know ehere i can?
        Thanks in advance,

  2. Hello,
    I’m Resantika from Netherland.
    I like to buy cosmos caudatus ( ulam raja) seeds please?
    I Trying for so long to Find this cosmos caudatus.
    Please let me know, if you Will sell it to me.
    Thank u.
    Regards from Netherland, Rotterdam.
    E. Resantika.

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