Sunlight: Full sun
Maturity: 65-90 days
Height: 4 to 6 feet
Spacing: 8 to 12 inches apart, 2 to 3 feet between rows
Native to North and South America, corn — or maize — was first cultivated some 4,000 years before Columbus set foot in the New World. Today, with more than 85% of the US corn crop genetically modified, it’s more important than ever for home gardeners to plant corn and preserve the good, old fashioned heirloom varieties that so many generations have enjoyed eating right off the cob (see Sweet Corn: Hybrid and Heritage).
Fun Fact: The United States produces about 40% of the world’s corn supply on 90 million acres, most of which is harvested in the Midwest.
Nothing says summer like fresh picked sweet corn grown in your own backyard.View all
All heirloom corn seeds offered by Planet Natural are non-treated, non-GMO and NOT purchased from Monsanto-owned Seminis. Planting instructions are included with each packet and shipping is FREE!
- Direct seed into warm soil located in full sun
- Corn is a heavy feeder, so prepare the planting area with plenty of organic matter
- Water faithfully
- Protect against wildlife like raccoon and deer
- Harvest 65-90 days after planting
- Pests and diseases include corn earworm and corn smut
Corn is a warm-season vegetable that requires full sun, ample water and deep, rich garden soil to perform well. Warmer temperatures at night also accelerate growth. Prepare the planting site by working in generous amounts of a quality organic compost or well aged animal manure. Corn needs to be well protected from frost.
Tip: Cover the planting area with black plastic for two to four weeks prior to planting to warm the soil and improve germination. Corn will not germinate if soil temperatures are below 55˚F.
How to Plant
Corn should be planted directly into the soil after it has warmed in the spring (two weeks after your average last-frost date). Sow seeds 1 inch deep, 8-12 inches apart. Corn is wind-pollinated, so plant in short rows or blocks to ensure even pollination. Undeveloped kernels indicate uneven pollination. Plant a new crop every two weeks to ensure harvest throughout the gardening season.
Consider adding kelp meal to vegetable gardens. It’s loaded with micronutrients and is especially good for supplying trace minerals to crops that will be consumed. It will also help guard against plant stresses such as insects, frost, disease and drought.
Make sure that the entire root zone is damp as corn ears mature by watering at the base of the stalks. Soaking the leaves rather than the roots washes away pollen and reduces the number of kernels that develop.
Corn is ready to harvest three weeks after tassels appear. Look for dark green husks, brown supple silks and plump kernels that squirt “milky” liquid when pinched. Corn tastes best when it is picked in the late afternoon and should be twisted from the plant in a downward motion. Sweet corn requires 65-90 days to reach maturity, depending on the variety.
Insects and Diseases
Rotate corn with other crops to prevent recurring pest or disease problems. Corn earworm, deer and raccoon are common pests of corn. Discourage animal pests with fencing, repellents and scare devices.
Spinosad is a relatively new biological pesticide that can be used to effectively combat earworms on corn. Mix 4 Tbsp. per gallon of water and treat silk frequently. Approved for organic use, spinosad — the active ingredient in Monterey® Garden Insect Spray — does not significantly impact beneficial insects and spiders while controlling pests.
Seed Saving Instructions
All heirloom varieties are wind pollinated and will cross-pollinate with each other. Varieties should be hand-pollinated or isolated by one mile to ensure purity. Allow ears to dry on plants, harvest and shell.
Contains NO sewage sludge or bio-solids that are often found in commercial brands.
Dried Blood (13-0-0)
Used for years by growers as a powerful, slow release source of nitrogen (13%).
American Pride (9-6-6)
A time-released, biologically active blend of potent, high test plant foods.
Kelp Meal (1-0.5-2)
Derived from Norwegian seaweed and infused with beneficial microbes.