Does kale have thorns? Most gardeners would say no, yet this question occasionally pops up on gardening forums, often accompanied by photos showing prickly kale leaves. These sharp spines on kale leaves can be abrasive and they certainly don’t seem very palatable. To prevent this from happening in your garden, let’s explore some reasons why kale is prickly.
Finding Spines on Kale Leaves
The simplest explanation for finding prickly kale leaves is the case of mistaken identity. Kale is a member of the Brassicaceae family. It’s closely related to cabbage, broccoli, and turnips. Turnip leaves are sometimes covered with prickly thorns.
From seed collection to labeling seedlings, mix-ups can and do occur. So, if you’re finding spines on kale leaves in your garden, it’s possible you might have inadvertently purchased turnip plants. The shape and frilliness of turnip leaves can closely resemble some varieties of kale.
The good news is turnip leaves are edible. They tend to be tougher than other greens, so it’s best to pick the leaves when young. Additionally, cooking softens the thorns, which makes turnip leaves palatable. Worse case, you can wait for the turnip roots to enlarge and you’ll have the benefit of a vegetable you hadn’t expected.
Why Does Kale Have Thorns?
A more complicated explanation is that some kale is prickly, depending upon the variety. Most varieties of kale belong to the same species (Brassica oleracea) as cabbage, broccoli, and cauliflower. This species of kale produces smooth leaves. Most cases of prickly kale leaves are found on Russian or Siberian varieties.
Russian and Siberian kale belong to Brassica napus, a species which resulted from crosses between B. oleracea and Brassica rapa. Turnips, with their prickly leaves, are members of the B. rapa species.
Russian and Siberian kale, as well as other members of the B. napus species, are also allotetraploid hybrids. They contain multiple sets of chromosomes, each set coming from the parent plants. This means the prickly leaf gene from the turnip parent can be present in both the Russian and Siberian kale’s DNA.
As a result, crossbreeding between various varieties of Russian and Siberian kale can bring out this genetic trait. Many times, varieties with prickly kale leaves are present in mixed kale seed packets. The non-specified varieties in these packets can come from uncontrolled crossbreeding in the field or may be the F2 generation of smooth-leaf hybrids.
Additionally, some varieties of Russian kale are bred for ornamental purposes and may grow spines on kale leaves. Since ornamental varieties are not bred for consumption, these leaves might not have the flavor or tenderness of culinary kale.
The Complete Guide to the 7 Varieties of Kale
W hat used to be one of those vegetables to avoid at the grocery store or farmer's market has become one of the biggest food trends. That's right, kale has grown tremendously in the culinary world and there's a lot of reasons why. First off, kale is super nutritious. Those dark, leafy greens are packed with protein, fiber, vitamin A, vitamin C, vitamin K, magnesium, iron, and calcium.
Second, kale has some interesting flavor it. It's kind of spicy and slightly bitter and the leaves are extremely hearty and hold up well to a number of cooking methods like sautéing, frying, or even baking .
Lastly, kale doesn't just come in one variety. There are a ton of kale varieties to explore and try out- Tuscan kale, red kale, baby kale, or the most common type, curly kale. You'll love adding a boost of healthy greens to your next dish or you can even try throwing some into your next morning smoothie. Let's take a deeper look at some of the types of this nutritious leafy green.
There is a right way and a wrong way to harvest kale. If you harvest kale correctly, the plant will continue to grow and produce leaves. If you harvest it incorrectly, the plant will stop growing.
Kale produces leaves on a stem. The leaves grow from the top of the stem and the stem will continue to grow taller and to make more leaves throughout the plant’s life.
When picking kale, it’s important to pick the oldest leaves first. Those are the leaves nearest the bottom of the plant. They are usually the biggest leaves.
If you cut the plant off at the top or harvest the smaller leaves growing in the center, it is very likely that you will kill the plant. You need to leave that center area at the top of the stem for the plant to keep on producing.
The video from Edible Urban Farm shows you quite simply how to harvest kale leaves correctly. Along with leaving the smaller, central leaves, it’s important not to harvest too much of the plant at a time. Pick a few leaves from each plant, leaving at least one third of the leaves intact.
Picking the oldest leaves from the kale when you harvest also ensures that you’ll be able to use up the entire plant. If you let the leaves sit on the plant for too long, they’ll turn yellow, according to Our Green Thumb Community Garden. Older leaves are also more likely to be tough.
Garden(er) foe: saddleback caterpillar
Saturday’s big gardening adventure came in the form of a venomous spine lodged in my leg. Ouch!
The culprit — a saddleback caterpillar — was munching on a kale plant. I didn’t even see him. I just stepped away from tending a tomato plant, and backed my leg into the caterpillar’s chosen kale leaf. Fast forward .0042 seconds, and I’m leaping into the air wondering what creature of hell had just attacked me. Based on the suddenness of the pain, I expected my assailant was a yellow jacket, hornet, or baby Velociraptor. I didn’t suspect a caterpillar. Especially not a 1-inch caterpillar.
But that’s exactly what happened. A close inspection of the kale plant I’d backed into revealed a mess of caterpillar damage, a bunch of run-of-the-mill cabbage worms, and a prickly little beast that I vaguely recognized from my trusty Audubon Society insect guide . I knew I’d found my attacker. The little thing was just loaded with short spines. Here’s a photo of him on my poor, half-consumed kale plant. Yes, that’s a head shot:
And, here’s another photo of the beast, taken after I’d very very very carefully removed him from the kale plant:
Prickly! Beware: Every one of those spines is loaded with hemolytic (blood-destroying) and vesicating (blister-creating) venom, and they will readily jab you whether you see the caterpillar or not. Long pants, long sleeves and gloves may offer some protection, but not complete protection — I was jabbed right through the denim of my jeans.
In North America, only the puss caterpillars of the moth family Megalopygidae are more venomous than the saddleback caterpillar.
Here’s how the University of Florida’s entomology guide (the best I found) describes the saddleback’s effects:
The spines of A. stimulea are strong, acutely pointed, and hollow. They embed deeply into tissue and break off, and can interrupt healing as the protoplasm from the venom glands dries into the tissue area. … The venom itself can cause a systemic condition called erucism or acute urticaria, for which severe symptoms may include migraines, gastrointestinal symptoms, asthma complications, anaphylactic shock, rupturing of erythrocytes, and hemorrhaging…
Reading this, I know I got lucky. No nausea. No migraines. No shock. Not even a rash. Just an immediate burst of super-intense pain that lasted until I removed that venomous spine (only one made it past my jeans) and numbed the area with a cube of ice. Very lucky. I think I escaped the worst of it because I was wearing jeans, which surely offered some protection (though clearly not enough). Also, I found and removed the single spine within a minute of getting jabbed. I was highly motivated — the tiny little spine HURT.
Still, I find it mind-boggling that an inch-long caterpillar can cause that list of symptoms. After a bit of searching around the internets, I found bunches of stories about much worse encounters with these nasty little guys. Some people even wind up in the emergency room. There’s a good collection of folks’ saddleback caterpillar stories here.
After a weekend of compulsive reading, I can offer the following information about these prickly caterpillars:
Full name: Saddleback caterpillar or saddleback caterpillar moth
Scientific name: Acharia stimulea (formerly Sibine stimule)
Range: The eastern half of the United States, from Massachusetts to Wisconsin and south to Florida and east Texas.
Diet: Saddleback caterpillars can feed on a variety of plants. The one that got me was on a kale plant, but reports also indicate they feed on deciduous trees and shrubs, vegetables, flowers, and just about anything.
Life cycle: The timing of this varies by region, of course. Adults appear to emerge at the onset of consistently warm weather (June/July in the far north of their range, February/March in the most southerly part of their range). Females lay clusters of 30-50 eggs, and the larvae hatch in about ten days. The caterpillars hatch and feed in a group until they’ve molted once or twice. Then, they disperse (not sure how far). It appears to take approximately four months for these caterpillars to reach full size, which explains why most interactions between saddleback caterpillars and people appear to happen in the late-summer months that’s when the caterpillars are larger and more likely to be encountered.
Note: Saddleback caterpillars develop their venomous spines after their first molt, which means that even very small saddleback caterpillars can sting.
How to avoid being stung: I’ll give you the bad news first. You can’t totally eliminate the possibility of a saddleback caterpillar attack. Well, that’s not entirely true. If you live in the eastern half of the United States, you could pack everything up and move west (where these caterpillars are not found). Up to you if you want to take things that far.
Otherwise, it’s just a matter of reducing risk:
- Wear long pants, long sleeves and gloves, especially in the late-summer months (yes, when it’s stinkin’ hot). I’m positive I got off easy because I was wearing jeans rather than shorts.
- Learn to recognize saddleback caterpillars.
- Be cautious when handling or walking past/through vegetation that shows obvious signs of caterpillar damage.
- If you find one, chances are good there will be more nearby. Carefully look over the host plant and neighboring plants. Be careful — you don’t want to feel the caterpillars before you see them. It may be wise to carefully remove the entire host plant (depending upon the plant, of course).
- Relocate or kill any saddleback caterpillars you find. Do whichever you think is best. But, bear in mind that one venomous caterpillar this year could turn into 30-50 venomous caterpillars next year…
However you deal with saddleback caterpillars, keeps this bit of information in mind:
Spines of urticating caterpillars can become airborne and consequently be inhaled or contact sensitive tissues like the eyes and nose. They may also embed in surfaces such as wooden tables and plastics, which become a contact hazard at a later time if the area is not cleaned. Stray spines can also get caught in fabrics, such as carpet, aprons and clothing and come into skin contact that way…
In other words: Be careful.
For even more information about saddleback caterpillars, including some fantastic photographs of the adult moths and young larvae, check out the species summary provided by the University of Florida’s entomology department: Saddleback caterpillars (Acharia stimulea).
Are you familiar with saddleback caterpillars or other unfriendly caterpillars? Any more tips to share that I may have missed? Please click here to add you advice in the comments section below.
Frequently Asked Questions about Green Caterpillars
Although some green caterpillars are referred to as worms, they are in a different class. Caterpillars such as inchworms and cabbage worms belong to the class Insecta. Worms are a species of invertebrate in the class Clitellata.
Why are caterpillars green?
Many caterpillars are green because it is a great camouflage mechanism in the wild. Some green caterpillar species have special markings to frighten off prey or make them look like venomous creatures.
Are green caterpillars poisonous?
Generally, green caterpillars are not poisonous. Some species ingest toxic substances from plants to give them a bitter taste to any animal that may want to eat them. Most green caterpillars don’t sting or bite.
What do green caterpillars eat?
Like most moth or butterfly larvae, green caterpillars need to gorge on plant food to increase their weight. This gives them enough energy to metamorphize into beautiful flying insects. Caterpillars tend to munch their way through leaves on the host plant. Only if there is a large infestation of caterpillars, will they do extensive damage.