Cogon Grass Root
bai mao gen · bái máo gēn
Imperata cylindrica (L.) Raeusch.
Quick Answer
About 8% of people who experience recurrent nosebleeds during hot weather fit the blood heat pattern that Cogon Grass Root may help address, and the same sweet, cold root also gently flushes heat through urine for those with dark, burning urinary output. Its mild taste makes it one of the few cooling herbs that can be drunk daily as a summer tea without discomfort.
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Take the Free Quiz →Summary
A sweet, cold root that cools the blood and stops bleeding while gently draining heat through urine. Cogon Grass Root is mild enough for regular use and is traditionally brewed as a summer cooling tea.
TCM Properties
| Botanical Name | Imperata cylindrica (L.) Raeusch. |
| Category | Cooling Herb |
| Temperature | Cold |
| Taste | Sweet |
| Channels Entered | Lung, Stomach, Bladder |
| Classical Source | Shennong Bencao Jing (circa 200 BCE) |
| Safety Rating | Non-toxic |
Key Concept
Cogon Grass Root(白茅根)
Where most blood-cooling herbs are bitter and harsh, Cogon Grass Root is sweet and mild. It cools the blood to stop nosebleeds and urinary bleeding, clears lung heat to calm dry cough, and promotes urination to flush summer heat, all through a tea that tastes pleasant enough for daily use. This combination of effectiveness and gentleness is rare among heat-clearing herbs, which is why it has served as both medicine and summer beverage across East Asia.
What This Herb Does
Cools blood and stops bleeding from heat
When blood heats up, it moves faster and pushes outside its normal pathways, producing nosebleeds, blood in the urine, or coughing up blood. Cogon Grass Root cools the blood directly, which slows the rush and helps the blood stay in its proper channels. Its sweet nature makes it gentler than other blood-cooling herbs like raw rehmannia.
Clears heat and promotes urination
Heat that collects in the lower body, producing dark urine, urinary burning, or swelling in the legs, may be flushed out through the Bladder channel. Cogon Grass Root promotes urine without being harshly diuretic, which means it clears heat while preserving the body's fluid balance.
Clears lung heat and relieves dry cough
The sweet, cold nature of this root enters the Lung channel and is particularly useful for the dry cough that accompanies warm weather or the aftermath of a respiratory infection. Unlike bitter, drying cough herbs, it moistens while it cools.
Generates fluids and relieves thirst
Because it is sweet and cold rather than bitter and harsh, Cogon Grass Root can be drunk as a daily tea during hot weather to replenish fluids and clear summer heat. This is one of the few heat-clearing herbs that is genuinely pleasant to drink, which is why it has been a popular summer beverage across southern China for generations.
Commonly Used For
Recurrent nosebleeds during hot or dry weather
TCM Interpretation: Frequent nosebleeds in summer or autumn often reflect blood heat, where the blood has been warmed beyond its normal range and pushes through the fragile vessels in the nasal cavity. The pattern is common in children and in adults who run warm.
Why Cogon Grass Root Helps: A daily tea of Cogon Grass Root for one to two weeks may help cool the blood and reduce the frequency of nosebleeds. Its gentle, sweet nature makes it suitable for children when dosed appropriately.
Urinary burning or dark urine from summer heat
TCM Interpretation: Dark, concentrated, or burning urine is a sign of heat collecting in the Bladder. Unlike urinary tract infections that require medical treatment, this pattern often reflects simple dehydration and summer heat that has not been flushed out.
Why Cogon Grass Root Helps: Brewed as a light tea and drunk throughout the day, Cogon Grass Root gently promotes urine while clearing the heat, often resolving the burning within a day or two when the cause is environmental rather than infectious.
Matching Cogon Grass Root to the Source of Bleeding
Cogon Grass Root stops bleeding from heat in multiple locations. Identify where the heat is expressing itself.
| If This Sounds Like You | The Signal | Start Here |
|---|---|---|
| Recurrent nosebleeds during hot or dry weather | Blood heat pushing through nasal vessels | Daily tea of 15-20g for 1-2 weeks, reduce if bleeding stops |
| Dark, burning urine with possible trace of blood | Heat in the Bladder causing bleeding and irritation | Stronger tea of 20-30g, drunk throughout the day for 3-5 days |
| Dry cough with scanty, blood-tinged sputum | Lung heat damaging the vessels | Combine with pear and lily bulb in a gentle soup, 1x daily for 5 days |
Which Body Types Benefit Most
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Related Symptom Guides
How to Use
Simmer 15-30g fresh or dried in water for 15 minutes. Drink as tea, 2-3 cups per day during hot weather or acute symptoms.
Dosage: 15-30g per day as tea.
Preparation Notes: Rinse the dried roots thoroughly before simmering, as they may retain sand. Fresh roots have a sweeter taste and stronger fluid-generating effect. Simmer for 15-20 minutes, not longer, as overcooking diminishes the cooling and fluid-generating properties.
Dietary Advice
Cogon Grass Root tea is one of the most palatable cooling teas in Chinese medicine, with a mild, sweet taste that requires no added sugar. Drink it warm or at room temperature, never ice-cold, as cold drinks counteract the Spleen's role in processing fluids. During hot weather, a daily thermos of this tea may replace plain water for a week or two without issue.
Food Pairings
Cautions
- ⚠Avoid in cold-type urinary patterns with clear, frequent urination
- ⚠Not suitable for Spleen Yang deficiency with loose stools and cold hands
- ⚠Long-term daily use beyond two weeks may gradually weaken digestion
- ⚠Stop use if loose stools or increased coldness develop
- ⚠Consult a healthcare provider for any bleeding that is severe or persistent
Frequently Asked Questions
Is Cogon Grass Root the same as the weed in my yard?+
Can children drink Cogon Grass Root tea?+
How is it different from lotus root?+
Which body type benefits most from Cogon Grass Root?+
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Take the Free Quiz→This article is for informational and educational purposes only and is not medical advice. Always consult a qualified healthcare professional before using any herb, especially if you are pregnant, nursing, or taking medication.