Let's Learn About the Spinach Plant

Maybe you buy this leafy green at the grocery store every week. Maybe you regularly toss it into green smoothies. But you're going to be surprised about some misconceptions we have about spinach.

Let's see if you can pick out the lie:

• Ninety percent of the US's fresh spinach is grown in just two places.
• Spinach has many health benefits, including being the most iron-rich food we can eat.
• Spinach ranks number two on the list of foods most likely to contain traces of synthetic chemicals.

Keep reading to find out which one's the lie. I love bringing you stories about the foods we eat, and spinach is a good one!

(Prefer to listen? Check out Episode 15 of the Grow Your Self podcast, "the Surprising Story of Spinach," on Apple, Spotify, iHeartRadio, and Stitcher.)

Most Spinach Leaves Travel a Long Way to Reach Your Plate

Spinach has really taken off in popularity over the last, say, 20 years. Everybody's growing more and selling more. And spinach plants are taking up more and more of our farmland. Believe it or not, the US is the second largest producer of spinach in the world. But get this: the US only produces three percent of the world's spinach.

China actually is number one. They produce 85 percent of the world's spinach! I tried to do research but honestly could not figure out what in the world they’re doing with all this spinach. I mean, are they eating it? Are they exporting it? My thought is that they're likely exporting frozen spinach, but from all this growth, I'm sure they're also eating a ton of it. 

When I lived in China, we had fresh greens on all of our dishes. It was never raw; we would always cook it in a soup or sauté it, but definitely fresh greens were a constant in every single meal. And obviously they have lots of people to feed in China. 

How Spinach Is Grown in the US

Most of our measly three percent of the world's spinach is grown in just four states: California, Arizona, New Jersey, and Texas together account for 98 percent of the commercial fresh spinach that's grown in our country.

What that generally means is that most of the spinach you're buying from the grocery store didn't come from anywhere near you, unless you live in one of those four states. And in fact, 90 percent of the U.S. spinach is grown just in California and Arizona. Most of our spinach, just like romaine lettuce, is grown in basically two places: Salinas Valley in California and Yuma Valley in Arizona. 

This is because spinach loves cooler weather. It loves temps between about 45 and 75 degrees. So most of our spinach is grown in California through their summer, spring, and fall, and then the growth moves over to Arizona in the winter. It’s kind of a bummer to think how much spinach is getting trucked across the country all the time, right?

And the acreage devoted to growing fresh market spinach in California keeps growing. In fact, in 2001, farmers gave about 15,000 acres to spinach, and then in 2011, just 10 years later, they gave 19,600. They attribute most of this growth to our increasing demands for baby greens. If you buy spring mixes or any of those plastic bags and boxes from the grocery store, those more than likely have a ton of little spinach leaves in them. 

Organic Spinach Is Expensive... but You Should Buy It Anyways

Farmers plant wide rows of densely sown spinach seeds, and then they use machines to clip the spinach leaves about two inches above the soil surface, allowing them to grow and harvest large batches of spinach all at once. We're talking two to four million seeds per acre.

"Baby" greens and teenage spinach leaves are typically harvested when they're about two to three inches long. This is what you're probably getting in those spring mix boxes and bags you're buying from the store.

When farmers are growing this much spinach in one area, you can imagine that there are some difficulties. (There are some great facts about how spinach is produced in the US here.) Difficulties include needing to use sprinklers to water the large spinach beds instead of drip irrigation, which means more water on the leaves (a no-no with leafy greens) and providing enough nitrogen for the plants to grow lots of healthy leaves.

Perhaps the biggest problem when growing spinach on a mass scale is treating weeds and disease in the field. The leaves get harvested and sorted by a machine, and the last thing farmers want is for the customer to open a box of spinach only to find a bunch of weeds.

If you're buying traditionally grown spinach instead of organic spinach, those leaves have been grown using pre-emergent herbicides to prevent weeds from growing alongside the spinach. When leaves are growing so close together, there's also an increased chance of things like downy mildew. So, farmers end up having to treat both for weeds and for pests and disease. (Learn more about the commercial spinach growing process here.)

Organic Spinach vs Regular

Ever wondered why organic spinach is so expensive?

In organic production, growers aren’t allowed to use those pre-emergent herbicides. Instead, they must perform a lot of weeding and organic pest control.

And this is why you see such a price difference when you're buying organic versus traditionally grown spinach; you're basically paying for that important labor of people weeding the fields rather than spraying these herbicides before the spinach even starts to grow. 

Even though it costs more, I encourage you to buy organic spinach (when you're not growing your own), and this is why: spinach continues to climb on the list of the Dirty Dozen.

The Dirty Dozen is a list of the top fruits and vegetables that you should buy organic, compiled by the Environmental Working Group. When tested, these 12 foods show up with the highest rate of pesticides and herbicides, basically synthetic materials that you do not want to be digesting.

The latest tests showed a big increase in pesticide residues on non-organic spinach. Spinach has risen to the number two spot on the list because of this increase. It's kind of a bummer to think that you're eating salad to be healthy, but unbeknownst to you, you're actually downing synthetic materials that are bad for you at the same time.

If you're trying to decide which things to buy organically and which things aren't as important, spinach is definitely one of those things that you want to prioritize buying organic for that very reason.

(Learn more about Environmental Working Group's important work and research on spinach here.)

Besides prioritizing organic, you could also focus on eating more seasonally, basically eating spinach when it can be grown near you, versus eating the spinach that's grown year round in California and Arizona and that faces production issues. Sure, a spinach salad in the heat of August might sound nice, but we often don't think about all that had to happen for that bag of spinach to be at the grocery store and at our disposal. 

Eating Spinach Leaves Will Make You Grow Big and Strong

Back in 1870, this guy named Eric von Wolfe, a German chemist, was examining the amount of iron in spinach and other vegetables. While he was writing down notes in his book, he accidentally moved a decimal point. Instead of saying that spinach has 3.5mg of iron per 100g serving, he accidentally wrote that there's 35mg in a 100g—basically 10 times the amount!

He made it seem like spinach was a supernatural superfood. Crazy amounts of iron in just a few leaves of spinach! 

Unfortunately, this mistake got printed, and people didn't question it. 

When the cartoon Popeye was created, little kids watched him get superpowers, basically, from eating spinach. Any time he needed strength to beat somebody up, he would swallow a can of spinach and suddenly become like the Hulk.

Doctors would even mix spinach juice with wine during WWI to help French soldiers build up their iron levels and recover faster.

It wasn't until 1981 when the British Medical Journal published an article to explain what had happened with the decimal error that the truth emerged. Basically, the world had been lied to about how much iron is in spinach. There is a lot of iron in spinach, but certainly not 35mg!

Also, even with a large amount of iron, it doesn't necessarily mean your body gets to enjoy all of it. Your body actually struggles to absorb iron from spinach in the same way it can for other foods. Studies do show that your body takes up more iron when you eat spinach cooked rather than raw. Still, if you're looking to maximize your iron intake, you're better off eating something like red kidney beans, which provide about 6mg per cup cooked.

Where Does the Spinach Plant Come From?

Spinach was first grown in Persia, or modern day Iran, before making its way to India and China, where it was called "the Persian vegetable.” Spinach was brought to Italy around 827. Muslims were the primary rules of the Mediterranean region at that time, and they grew spinach like crazy; they called it “the chieftain of leafy greens.” 

Spinach came to England and France in the 14th century by way of Spain. They loved that spinach could grow in the cooler temps before most of their other vegetables in the early spring, so it filled a veggie void, especially during Lent when other types of food were off limits.

Catherine de Medici, the queen of France, loved spinach so much that she ordered it for every single meal. She was from Florence, so even nowadays, dishes that have spinach in them are often called “Florentine” because of her.

The first record we have of spinach being grown in North America comes from 1806, when spinach was finally brought over by Europeans and cultivated here.

Learn more about the history of spinach in this great article.

Types of Spinach to Grow

Spinach is a member of the Amaranth plant family. This is literally the superfood family. I don't know if there is a plant family that we eat in our everyday dishes that could be better for our bodies. Inside of this plant family are beets and Swiss chard and other foods full of antioxidants, vitamins, and tons of fiber. 

There are three different types of spinach.

Savoy Spinach

Savoy is really another word for “bumpy," so savoy is the bumpiest kind of spinach.

Semi-Savoy Spinach

Semi-savoy is just what it sounds like. It's sort of bumpy, sort of not. 

Smooth Spinach

Smooth spinach is generally the type we buy at the grocery store, mostly because it's much easier to clean. When you have all those bumps in the leaves, it's harder to remove the dust particles and dirt and stuff like that.

Spinach Health Benefits

Spinach is a great source of all kinds of nutrients, like vitamin A, vitamin C, Vitamin K, Vitamin B, and iron, as you heard earlier, just not as much iron as that guy thought.

Spinach also has magnesium, which relaxes our nerves and muscles and can also prevent leg cramps while sleeping. Spinach is a good source of calcium and supposedly helps your brain manufacture melatonin, so you can make yourself a little spinach smoothie at dinner and see if you just might sleep better. 

Learn more about the nutritional facts of eating spinach here. 

Spinach Growing at Home

After hearing how spinach is grown in mass and trucked across the country, hopefully you're feeling encouraged to try to grow your own. 

The spring and fall are great times to grow spinach in colder climates, when temps are below 80 degrees. In Houston, we grew spinach through the mild winters.

Spinach loves to grow in a sandy loam soil. It doesn't like its roots to stay super wet, so the drainage provided by the sandy loam soil helps a lot. You can learn all about setting up your garden with a great sandy loam soil base inside Kitchen Garden Academy or in my book, Kitchen Garden Revival. 

Spinach grows super fast. In fact, those mass producers say they start harvesting it around 25 days after planting, which is speedy. If your temperatures are staying fairly low, you can do what we call successive planting to get a continuous supply of fresh spinach.

Learn more about growing your own spinach in our online guide.

Hope you enjoyed the surprising story of this leafy green! I love sharing the stories of these veggies and tips to grow your own so that we can all feel a little more connected to our food.