How to grow Sweet Corn

Zea mays var. saccharata

Requires warmth and sunshine to crop well

Growing Sweet corn from seed

Soak kernels in water overnight before sowing. Some people suggest buttermilk.
In climates with a short season, put 3 seeds in a 7cm pot and germinate on a bright windowsill or cold frame.
Pot on as the plants grow and keep under cover until the ground has warmed.

Look to ensure a distance 7.8 inches (20.0 cm) between seeds when sowing - bury at a depth of at least 1.17 inches (3.0 cm) deep. Soil temperature should be kept higher than 21°C / 70°F to ensure good germination.

By our calculations*, you should look at sowing Sweet corn about 14 days after your last frost date .

Transplanting Sweet corn

Planting out too early will make the plant cold and delay its growth. When the ground has warmed plant out in a block rather than a row, to aid the wind pollenation.

Ensure that temperatures are mild (minimum night temperatures should be around 15°C / 59°F) and all chance of frost has passed before planting out, as Sweet corn is a tender plant.

Harvesting Sweet corn

Sweet corn is ready to harvest when the ears feel full and the tassels have turned from green to yellow or brown. Peel back one of the husks and pierce a kernel with your fingernail, if the juice is milky it is ready.2 Another way of knowing corn is ready is when raccoons have eaten it all.2

Sweet corn should be eaten quickly after ripening. If you have more then you can eat you may can or freeze for later use. The easiest way to store is to simply place whole ears, husk and all, into a freezer bag and freeze as quickly as possible. Then the whole ears may be microwaved or grilled later. Kernels may also be frozen off the cob which saves freezer space.

When harvesting for seed leave the ears on the stalk for as long as possible, preferably a few weeks after the stalk turns brown. Brake the ears off of the stalks and pull back the husks then string up by the husks to dry for 2-3 months. When fully dry the kernels will easily come off from the cob. Hold the corn over a paper bag or other container and twist your wrists in opposite directions (like wringing) to remove the kernels. Store the seeds away from rodents and moisture.3

Seed Saving Sweet corn

Ripen on the plant and harvest when the cob begins to Feel dry and hard. Continue to dry on a bright windowsill, if necesary

How long does Sweet corn take to grow?

These estimates for how long Sweet corn takes to sprout, grow and harvest are from real observations from real gardeners, right around the world.

Days to Germination How long does it take Sweet corn to germinate?
8 days

Average 8 days | Min 1 days | Max 21 days (309)

Days to Transplant How long until I can plant out Sweet corn?
+ 30 days

Average 30 days | Min 2 days | Max 52 days (21)

Days to Maturity How long until Sweet corn is ready for harvest / bloom?
+ 88 days

Average 88 days | Min 52 days | Max 140 days (15)

Total Growing Days How long does it take to grow Sweet corn?
= 126 days

When should I plant Sweet corn?

Our when to plant Sweet corn estimates are relative to your last frost date.

When to sow The number of days to sow Sweet corn before or after your last frost date.
14 days after Last Frost Date

Other names for Sweet corn

Corn, maize

Zea mays var. rugosa

Misspellings: Corn on the Cob, Cob Corn, sweetcorn, sweet corn, Maize, Green mealie

Footnotes

1 Wikipedia list of companion plants

2 All About Sweet Corn

3 How to Dry Corn Seeds

4 European Corn Borer

5 European Corn Borer Control on Planet Natural


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