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Written by: Kristina Langan, Colorado Master Gardener

            I do not have a green thumb. I have figure out everything with my brain. I started figuring out how to grow vegetables in the 90s under the tutelage of my drunk punk rock housemate in Oakland, CA. One year, we decided to grow corn. He had never done this, and because this was pre-internet, we just did whatever: we planted one row along the fence line. We got a lot of ears, but very few kernels. We wondered what went wrong, and then promptly went back to growing the things that worked.

Corn planted in wooden square garden beds

            Years later when I moved to the Hispanic side of town, I noticed that many people grew their corn in a square, instead of in rows. Because corn is wind-pollinated, when grown in a square the pollen from the tassels is much more likely to reach the silk to allow full fertilization of the kernels. It wasn’t long until this tidbit of information got me to start fantasizing about ripping out all the grass and growing a corn field in my new yard. The monoculture home garden. Landlord says? Nope.

            Now I’m all grown up and have my own house on a quarter acre lot where I can do whatever I want, and where I have to do something, otherwise I will have a yard full of kochia weed and goatheads. I’m working on several fun ways to use my land, but the first project is raised beds, and, with corn in mind, I made four 4’x4’ beds together in a square, with about two feet between for access. And what type of corn? I had recently learned about the amazing variety in heirloom corn, and I decided on one of the traditional corn varieties in Peru: maize morado.

            When we in the US think of corn, we are likely to think of the great expanses grown in the midwestern states. We might think of it as a GMO monoculture, and indeed, 92% of corn grown in the US is GMO, and the US grows only about ten varieties of corn. Meanwhile, Mexico has 59 varieties of indigenous corn, and Peru has 55 varieties. We might also think of it also as overly pervasive in our diets. High fructose corn syrup is found in an overwhelming amount of processed foods and, along with heavy consumption of sugar in general, is currently considered to be a primary source of health problems in the US. Our high levels of corn consumption can be shown by testing for carbon isotopes: isotopes specific to corn can make up around 60% of the carbon in an American’s body.  Author Michael Pollen has suggested that we Americans are the modern “people of the corn.” But corn can be the basis of a healthy diet, and has been in the Americas for thousands of years.

            Maize morado has beautiful deep purple kernels heavy in anthocyanins, antioxidants that help prevent cancer. The Peruvians bred this variety for the high mountains of the Andes, where the purple pigment protects it from intense UV levels. You’d think they’d have a short growing season, but planning for 100 days was recommended for the variety I got from Baker Creek. So, um…not such a great choice for a heavy procrastinator like myself. Then again, I thought: 100 days, that’s a little over three months, and with Colorado’s long-lasting summers, I could probably count on September being at my disposal. So it began, foolishly, in June.

            My first act of reason was to finally follow the principle that great soil is the key to healthy plants. I trucked in soil for the beds, but soon realized I would need to amend: the soil was too heavy. I added peat moss to the first two beds, which was a lot more work than I expected! It still seemed heavy, so I added perlite instead to the second two beds. Surprisingly to me, initial growth rate was best in the peat moss only beds. Organic matter and lower pH won out. Later, I pulled some out to compare the root masses, and the perlite beds did have more expansive root systems. In the end, all plants were happy and healthy; some grew to seven feet tall. I had some aphids in the silk, and some corn worms, but nothing disastrous.

two small ears of corn with reddish purple grainsRate of growth comparison between peat moss amended vs perlite amended soil
three stalks of corn showing rootsRoot mass comparison between peat moss amended vs perlite amended soil

            The next life-long habit I had to contend with was my procrastination. I decided to give the plants a head start by soaking them to germinate before planting. After 24 hours, I drained the water, put the kernels on a damp paper towel and wrapped it in foil to make it dark. It worked! I never get over seed germination. Such a wonder. I planted the pre-germinated and dry seed and compared. No contest. My corn was growing fast, and I had avoided the May hail. “I am smart!” I said to myself.


corn germinatingIndoor germination with damp paper towel wrapped in foil

Then I started reading up about the three sisters method. I wanted to get the timing right for planting the beans and squash. I found a great source of information: Native Seeds/SEARCH (NS/S), a nonprofit seed conservation organization based in Tucson, Arizona. A very detailed description, and their techniques are specific the high dry heats of Arizona that we also have here in Pueblo. I planted my beans.

Reading further, however, I found out some bad news. The main reason for planting corn early in our region is not the length of the season. Instead, it is a matter of timing when pollination happens. As many of us discovered this year with our tomato plants, high heat makes pollen sterile. Planting early allows the pollination to take place when the temperatures are lower. The other downside of planting late messed up my three sisters project: it was too hot for the beans to germinate.

Now don’t get sad for me: I love so much to experiment and learn that the product of my gardening is fairly unimportant to me. I’m not going to starve if my corn doesn’t have a high yield. The other thing I love is just being with the plants. I spent a good amount of time just standing in the center of those four beds. I love the sound of corn. And maize morado is a beautiful plant: not only does it have purple kernels, but the leaves and stalks are streaked black, purple, red. The tassels are dusky, and the silk almost magenta. It puts out several levels of black nubs that can grow into brace roots, grows several stalks per plant, and a huge amount of ears, from the top of which the husks jut out at an angle, resembling palm fronds.

head of corn showing red top tassleMagenta colored silk
brace roots on cornBrace roots

The next challenge was to determine when these many ears were ripe. Most didn’t fatten up to look like store-bought sweet corn. But I learned that it is typical for heirloom varieties to have smaller, thinner ears. I did a lot of “exploring,” pulling back the husks to examine the kernels. The larger ears often had one main well-developed ear with dark mature kernels, and then one or two smaller, pale yellow ears of baby corn. (So that’s where baby corn comes from!) I did end up having pollination problems, but still harvested quite a few beautiful ears with full arrays of ripe kernels. I learned, however, that hand-pollination is a good idea even for the common yellow and white varieties of sweet corn.

ears of corn with ripe kernelsSome of the ears with full arrays of ripe kernels

Then for the tasting! Eating maize morado as a sweet corn is less common than using it as flour. Peruvians also make a popular drink called chicha morada, and the dessert pudding mazamorra morado. But, as I had only a few fully developed ears, I decided to eat it on the cob. Ok, so I forgot to use that brain of mine for that decision: my fingers and mouth and face were soon dyed bright purple! It washed off within the day, though, and the taste was well worth it: less sweet than our American corn on the cob, rich and nutty. So yes, armed with all my hard-won knowledge, I will grow it again next year if I can get some seed. It sells out fast!

purple stain on hands from corn kernelsYou should have seen my face

(Please let me know if you would like any links to my sources by emailing me at Thanks!)

From the Ground Up, Fall 2020