Sweet corn is one of the most delicious and nutritious vegetables that you can grow in your garden. While the process of growing sweet corn is relatively simple, many people struggle with knowing when to harvest their corn. In this article, we will discuss the details about how to know when your sweet corn is perfectly ripe.
Understand the Life Cycle of Sweet Corn
Tip: Understanding the life cycle of sweet corn is essential to ensure that you harvest your corn when it is perfectly ripe. Sweet corn is a warm-season crop that takes approximately 60 to 100 days to mature, depending on the variety and planting region.
Planting and Germination
Stage 1: Planting – Sweet corn can be planted directly in the ground, approximately 2-3 weeks after the last spring frost. Plant sweet corn in well-drained soil with full sun exposure for maximum growth.
Stage 2: Germination – Sweet corn requires warm soil temperatures of 60oF to 65oF to germinate. Germination typically takes 7 to 10 days, depending on soil moisture, temperature and seed quality.
Vegetative Stage
Stage 3: Vegetative Growth – Sweet corn plants grow rapidly and develop leaves, stalks, and roots during the vegetative phase. In this stage, the plant requires adequate moisture to ensure proper growth and development.
Tasseling and Pollination
Stage 4: Tasseling – Although sweet corn plants are monoecious and develop both male and female flowers, the tassel is the male structure that releases the pollen. The tasseling stage occurs about 20 days after the silks first appear.
Stage 5: Pollination – After the tassel appears, sweet corn plants will begin to pollinate. Each silk needs to receive pollen to produce a kernel. Sweet corn ears can have up to 1,000 silks, which is why sweet corn requires significant amounts of pollination.
Ear Development and Ripening
Stage 6: Ear Development – Sweet corn kernels start developing right after the silk is pollinated. The kernels at the base of the ear will mature first, while the kernels on the top take longer to develop fully.
Stage 7: Ripening – As sweet corn is ripening, the kernels start to fill out and become plump. The husks are also becoming dry and starting to turn brown. These are signs that sweet corn is ready for harvest.
Check for Outer Husk Signs
Tip: Checking the outer husk signs is a simple way to determine whether your sweet corn is ripe and ready for harvest.
Green and Tightly Wrapped Husks
Sign 1: Green and Tightly Wrapped Husks – The husks on fresh corn should be green and closed tightly around the kernels. This stage of the corn is not ready for harvest, and you should wait for the husks to dry before harvesting.
Partially Opened Husks
Sign 2: Partially Opened Husks – As the corn is ripening, the husk will start to open and expose the upper part of the ear. You can gently pull back the outer leaves to check whether the kernels are developing and fill out.
Dry and Brown Husks
Sign 3: Dry and Brown Husks – When the corn is perfectly ripe, the husk will dry out and turn brown. The kernels in the ear should be plump, and milky juice should appear when you pierce them with a knife.
Check for Kernel Ripeness
Tip: Checking for kernel ripeness is another way to determine whether your sweet corn is perfectly ripe and ready for harvest.
Check Kernel Color and Texture
Step 1: Check Kernel Color and Texture – The kernels in sweet corn should be plump, tender and not too hard when ready for harvest. The color of the kernels can vary based on the variety of corn you are growing. Most sweet corn varieties are yellow, while others can be white or bi-color.
Squeeze Test
Step 2: Squeeze Test – Gently squeezing a kernel with your thumbnail should produce a milky liquid. If the liquid is watery, the corn is not yet ready, and you should wait for the kernels to fill out more.
Tug Test
Step 3: Tug Test – You can do a “tug test” by gently pulling on the husk once it has turned brown to see if the ear is ready for harvest. Ripe ears will come off the stalk easily.
Factors Contributing to Sweet Corn Ripeness
Tip: A combination of factors contribute to the ripeness of sweet corn. Make sure you take these factors into consideration before harvesting your sweet corn.
Variety and Days to Maturity
Factor 1: Variety and Days to Maturity – Different types of sweet corn have different flavor profiles and maturation timelines. Early maturing varieties take around 60 days from planting, while later-maturing varieties can take up to 100 days for fresh corn to mature.
Climate and Soil Type
Factor 2: Climate and Soil Type – Sweet corn needs warm soil temperatures and a steady supply of water to develop correctly. Well-drained soil, full sun exposure, hot weather, and enough water are essential factors that contribute to sweet corn’s ripeness.
Storing and Preserving Sweet Corn
Tip: Once you’ve harvested your sweet corn, it’s important to store and preserve it correctly for the best flavor and texture.
Short-term Storage
Method 1: Short-term Storage – You can store fresh-picked corn in the refrigerator with the husks still on, but the flavor will start to diminish within a few days.
Freezing Sweet Corn
Method 2: Freezing Sweet Corn – One of the best ways to preserve sweet corn is to freeze it. Remove the kernels from the cob, blanch them in boiling water for a few minutes, and then freeze them in a resealable bag. Frozen sweet corn can last up to 8 months in the freezer.
The Most Common Questions About Harvesting Sweet Corn
Tip: Here are the answers to some of the most common questions about harvesting sweet corn.
- Q: How many ears of corn can you harvest per stalk?
- A: One stalk of corn typically produces one good-sized ear of corn.
- Q: What happens if I don’t harvest the sweet corn on time?
- A: If you wait too long to harvest sweet corn, the kernels could become starchy, tough and lose their sweet flavor. Also, the sugar levels in sweet corn start to convert into starch soon after picking, which will cause the quality and flavor to deteriorate.
- Q: Can I harvest sweet corn when it isn’t completely filled out?
- A: It’s best to wait until the kernel plumps up completely before harvesting, so it’s never advisable to harvest before the kernels are ready.
- Q: How long does it take for sweet corn to grow?
- A: The growing process of sweet corn takes around 60-100 days, from planting to harvest depending on the variety of sweet corn.
References
Here are some references that we used to gather information for this article.
- Purdue University Extension – Sweet Corn Production
- University of Illinois Extension – Sweet Corn
- Iowa State University Extension and Outreach – Sweet Corn