Cultivated by ancient civilizations all across the Americas, the corn plant, or maize, has remained a staple in the human diet and is the most commonly planted crop in the US today. The most planted types of commercially-grown corn, such as field corn and sweet corn, possess long green stalks and the well-known yellow kernels, but there are many other varieties available that differ in color, levels of sweetness, and purpose (e.g., livestock feed versus picnic corn-on-the-cob). For home gardens, we recommend picking a variety that will match your needs, climate, and level of growing expertise.
Trinity sweet corn is a delicious early varietal perfect for areas with short growing seasons since it reaches maturity in as little as 60 days. These plants are a bit shorter in height than many other varieties, reaching only about 5′ tall, and are thus also a great option for gardeners with limited space. The stalks produce 8–9″ ears that sport bi-color kernels renowned for their plumpness and sweet flavor.
Seed Depth: 1–1.5″
Space Between Plants: 12″
Space Between Rows: 24–36″
Germination Soil Temperature: 70–80°F
Days for Germination: 5–10
Sow Indoors: Not recommended if you’re planning on transplanting outdoors as corn doesn’t like being moved. The Trinity varietal can be grown in containers, however, so if you’re planning on leaving them in a pot, start indoors in the early spring.
Sow Outdoors: 1–2 weeks after average last frost date.
Grows best in warm weather and will not tolerate frosts. Requires soil temperatures of over 65°F for good germination.
Natural: Full sun.
Artificial: Will grow under high output fluorescent or HID lamps. Needs at least 6 hours of light daily; however, more is preferred.
Soil: Prefers well-drained loamy soil with a high amount of organic matter. A pH of between 6.0 and 7.0 will keep plants healthy and nourished. Generally, the earlier you are planting, the lighter and sandier soil you want. Later crops will prefer a heavier soil.
Soilless: For container growing, use a soilless mix with plenty of nutrients.
Hydroponics: Thrives in hydroponic systems, including media beds, but will need a lot of space.
Aeroponics: Thrives in aeroponic systems, but will need a lot of space.
Water: Requires moderate to high levels of water. Aim for about 1 inch of water per week. Use drip irrigation to prevent water from getting on leaves. Production will be best with consistently moist soils, but avoid overwatering or allowing water to pool at the base of plants. The most important time is the few weeks leading up to the corn’s silk production.
Nutrients: Requires high levels of nutrients, particularly nitrogen and phosphorus. Amend soil with cottonseed meal and/or compost before planting. Sidedress with compost, liquid kelp, or fish emulsion when plants are 6″ tall and again when they are knee high.
Foliar: Will benefit from foliar feedings of compost tea.
Mulching: Use mulch to conserve moisture, moderate soil temperature, and keep weeds under control.
Covering:Protect young plants from light frosts using row covers. In cooler climates, grow corn in dark-colored raised beds or containers to warm the soil.
Other: Corn has shallow roots, so take care when weeding not to damage them. Also, hybrid sweet corn should not be allowed to cross pollinate with other types, so for best results, separate varieties by at least 250 feet. You can also time plantings so that different varieties do not bloom at the same time.
DEFICIENCY(S): A nitrogen deficiency will result in slow growth and reduced production.
Rotation: Plant corn after clover, beans, peas, or other nitrogen fixing crops. A 3- or 4-year rotation is recommended.
Companions: Grows well as a member of the Three Sisters. Avoid tomatoes.
Harvest: Pick ears of corn off their stems carefully and with a slight twist when the silks are beginning to turn brown and dry out and the ear feels plump and full, usually about 3 weeks after silks first appear (earlier if growing in warm weather). You can check the ears by pulling the outer husk back and poking a kernel. Ripe kernels will emit a white milky sap; if underripe, the sap will be clear, and if overripe, it’ll be too creamy. It’s best to harvest in the morning when plants are still cool.
Storage: Keep ears of corn in the refrigerator for up to one week. The earlier you eat it after harvest, the sweeter the kernel will be. If stored too long, sugars convert to starch.
Fun Fact: Corn—as we know it—is actually a man-made creation stemming from a plant known as teosinte, which is why you can’t find corn in the wild.
Preserve: Corn can be frozen fresh or blanched and frozen for later use. Also try canning fresh kernels using a pressure canner.
Prepare: Sweet corn is a big part of traditional Latin American diets. Commonly paired with beans, the two plants together provide all the necessary amino acids for good health. Add fresh raw kernels to salads and salsas. Boil, grill, or steam and eat straight off the cob for a buttery afternoon snack.
Nutritional: A gluten-free cereal, sweet corn is a good substitute for gluten products for those with celiac disease or a gluten intolerance. Sweet corn is one of the best sources of dietary fibers as 100g can provide 5% of daily fiber. Sweet corn also possesses high levels of ß-carotenes, vitamin A, flavanoids, lutein, xanthins, thiamin, zinc, magnesium, copper, iron, manganese, and ferulic acid.
Medicinal: Ferulic acid is being studied for potentially anti-cancer properties, while flavonoids may prevent lung and oral cavity cancers.
It’s hard to improve upon the flavor of sweet corn straight off the cob—that is, unless you’re pairing it with fresh herbs and other tasty veggies like this Mung Bean Salad With Corn and Basil recipe.