June 20, 2020

Katuk - A Steamy Summer Sweetheart

Katuk flowers on the
underside of the stem

I hold katuk in high regard. It is a tasty, leafy green that is available almost year-round, grows easily, produces profusely, is easy to harvest, and has high nutritional value. But you may not have heard of it, because the plant has a strong predilection for high heat and humidity and is primarily grown in the tropical climates and rainforests of Southeast Asia. I can attest that high heat and humidity are also classic hallmarks of summer in coastal and South Florida. And now that the summer solstice is upon us, katuk is kicking up its heels and parading its leafy cavalcade. 

When I lead visitors through my forest garden, I always stop at the katuk bush (Sauropus androgynus).  When I let people sample a leaf, most think it tastes familiar but can't quite put their finger on it. Not infrequently someone will say it tastes nutty. In their mind, most are comparing it to other leafy greens they know, but their rolodex is coming up empty. They are relieved when I ask if it tastes like a green pea, for that is exactly the flavor most perceive.

Katuk grows into a tall bush. Keeping it pruned below six feet prevents it from flopping over and encourages bushier growth. It does fine in my sandy soil with inconsistent rain, tolerating some drought. With a little irrigation, it produces continuous new growth all summer and into the fall. It also doesn't mind clay soils. Nor does it care too much about soil pH or nutrients. My plant is in almost full sun, but its native habitat is in rainforest understory, so it would probably do better with a little more shade. However, it does not take kindly to the cold. As evening temperatures dip below 50°F, the plant can best be described as not quite dead. If katuk were an animal, I would say that it hibernates. The leaves metamorphose from soft to papery, and who likes to eat paper? Katuk is recommended for USDA hardiness zones 9b-11. In Central Florida, which experiences occasional freezes, the plant typically dies back, but will rebound as the weather warms up in the spring.
Katuk leaves stripped from stems
You can use katuk leaves, just as you would any other leafy green in a salad. Quickly strip the leaves from the stem by pulling it between your fingers. They add a bright note to a salad without any additional cutting, chopping, or tearing. The flowers and fruit are also both edible. You can add the leaves, shoots, flowers, and/or fruit to a stir-fry, rice, scrambled eggs, soups, or casseroles. I like to layer the leaves in nachos.

Recently I wanted to make a dish where katuk was the dominant ingredient. After these many years of eating katuk, I had never done so. I embarked on the katuk soup experiment. I boiled a potful of katuk leaves with some salt, powdered garlic, minced onion, and key lime, pureed it in the blender, and returned it to the stove top to let it settle. Since I think almost everything tastes better with a little peanut butter, I mixed in a glob of peanut butter and left the soup flavors to meld and marry over super-low heat. It had a nice flavor and made a fine sauce for potatoes the next day.

According to my reading, katuk packs a punch, nutritionally. It is reputedly high in protein, fiber, iron, calcium, magnesium, beta-carotene, and vitamins B and C. I was thinking that when katuk dominates a dish, as it did with my experimental soup, there would be some nutritional benefits, even after cooking it. Unfortunately, there is a bit of a data mess online. 
Question: How many grams of protein are in 100 grams of katuk leaves?
Answer: 25 grams, give or take 20 grams !!

Of the 100 grams, 76-80 grams are straight-up water. So there can't be more than 24 grams of everything else combined. There are numerous sources that indicate there is somewhere in the vicinity of 5 grams of protein in every 100 grams of katuk leaves. That is still remarkably high for a green leaf. By way of comparison, spinach has 2.86 grams of protein in every 100 grams.  However, if I go by mouth-feel, katuk is much drier than spinach. So, of course there would be less protein, because there is more moisture. After bandying the numbers around for a bit, I have come to a conclusion. If we all ate only powdered foods, it would be much easier to compare nutrition facts. With that, I will provide a blank chart and leave it to the biochemists and nutritionists to continue their analyses.

   Protein   Beta Carotene   Calcium   Vitamin B   Postassium   Iron 
 Katuk Leaf             
 Green Pea            
This Chart Intentionally Left Blank

Great potential for a katuk hedge
Some farmers grow katuk for their tender new shoots.  By applying plenty of fertilizer, consistent irrigation, and a bit of shade, they are able to make the tips grow quickly. Some shrewd marketing folks came up with a name for the top 4-inch section of these tips - tropical asparagus. If you are after some tropical asparagus, you will need to pay a bit more attention to your growing methods. On the other hand, if you are looking to grow a hedge of katuk, plant them more closely together and prune regularly. If, like me, you are looking to do less work, katuk fills the bill. It is a perennial that grows quite nicely without disease or pest problems, requiring with very little attention.

Speaking of perennial vegetables, I have noticed that most of the perennial greens have a strong flavor. For example, katuk tastes like green pea. I think this is because they produce "strong" compounds that can ward off pests. Otherwise how would they survive year after year in Florida, known for its outsized insect populations? The insects are put off by the strong flavors/smells from these compounds and go elsewhere. Of course this is just Diane's theory; I have neither researched nor tested it.

Due to the strong flavors, it took me several years to figure out how to make a Florida summer salad that I liked. Early on, there were so many competing, off-putting flavors and textures that I resorted to layering the greens in nachos. But then I learned how to work with them. Add some fresh figs or some grated green papaya to tone it down. Or add some strong cheese or pickled ginger to overwhelm it. Or do both. In addition to enjoying katuk's awesome flavor, katuk cuttings make a nice edible centerpiece.
Making nachos with 
katuk and chives
Katuk cuttings make a great 
edible centerpiece
For my friends in colder regions: You have so many leafy greens that grow all through the summer, don't lament the fact that you may not be able to grow katuk. However, if you decide to give it a try, you will probably have the best luck growing it in a container and then protecting it from the cold. And you may experience a bit of schadenfreude, when you consider how difficult it is to grow most of the common leafy greens in Florida during the summer.

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