Why is corn a plant with one seed

Sweet corn


Sweet corn (Zea mays), also known as sweet corn or vegetable corn, is a variety of corn within the sweet grass family (Poaceae). It differs from fodder maize primarily in that the sugar is only slowly converted into starch when it is ripe. As a result, the kernels of the corn on the cob taste pleasantly sweet when harvested.

The maize plant originally comes from Central America, where the grain already played a very important role as a useful plant for the indigenous peoples. Sweet corn was probably created at the end of the 18th century through a mutation from fodder or edible corn. There are now seeds for numerous types of sweet corn, which were mainly bred in the USA, the world's largest corn producer. This means that sweet corn can be grown not only in the field, but also in the garden at home.

Appearance and stature

Sweet corn is an annual, herbaceous plant that reaches heights of between 60 centimeters and three meters. A strong and upright stem envelops alternate, grass-like leaves that are five to ten centimeters wide. Zea mays blooms separately from the sexes monoecious, so it forms male and female flowers on each plant. In July / August, large, yellowish-purple flower panicles appear at the end of the stem. These are the male flowers, also known as the flag. The female flowers sit in a bulb in the leaf axils and are surrounded by bracts. During the flowering period, long stigmas (style) grow out of this bulb, onto which the pollen is transported by wind. Depending on the variety, one to three corn cobs that are 10 to 40 centimeters long develop per plant. The protein and carbohydrate-containing grains are white to golden yellow, sometimes reddish, purple or black, and shrink when fully ripe.

Location and soil

Sweet corn needs a sunny spot on the northern edge of the vegetable patch. This way, other types of vegetables are not shaded by the tall plants. The soil in the field should be deep, humus and rich in nutrients for the vegetables. It is important to avoid waterlogging.

Crop rotation and mixed culture

If you grow maize in the garden, the space between the rows of maize can initially be used for quick crops such as radishes, lettuce or spinach. Beans, cucumber or tomatoes are also suitable. Peas, radishes and asparagus are bad neighbors.

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Use only fresh seeds for sowing maize. In warmer regions, you can sow sweet corn directly into the prepared bed from early to mid-May. The earth should have a constant temperature of at least 14 degrees for the heat-loving vegetables. Corn is one of the medium to heavy consumers. Before growing corn in the vegetable patch, you should spread three liters of ripe compost and about 70 grams of horn meal per square meter and work it flat into the well-prepared soil. Place a kernel of corn at a distance of 10 to 15 centimeters from the seed in a groove about three centimeters deep. You should leave 50 to 60 centimeters of space between the rows. For optimal pollination, we recommend growing in squares made up of several short rows. In cool, rough locations, the preculture of sweet corn in small pots in the greenhouse or on a sunny window sill has proven its worth. It is best to use potting soil or normal vegetable soil and put a kernel of corn in each pot, as the plants germinate quite reliably. Then they are covered with a transparent hood and kept well moist. Earlier sowing directly into the bed from mid / late April is also possible if the seed rows are then covered with a foil tunnel.

Plant sweet corn

After the ice saints at the beginning of May, pre-cultivated sweet corn is placed in the bed with the pot balls and watered thoroughly. The planting distances are identical to those for direct sowing. So that the roots become stronger and the plants get a better hold, they are piled up around the stem. A fleece cover is recommended in the first week after planting. This is particularly important if the young plants have not been thoroughly hardened before moving them into the field. Black foil around the planting area keeps the roots nice and warm.


In the first few weeks after sowing, the main thing is to keep the bed weed-free. For example, you can mulch it thinly with slightly dried grass clippings or a mixture of grass clippings and old autumn leaves. When the plants are just under knee high, it is time for a second application of fertilizer. It is best to supply the vegetables with around 70 grams of horn meal per square meter until mid-July. The fertilizer is spread in the root area of ​​the plants. When it is dry, sweetcorn should be watered in good time. Although it is relatively drought tolerant, the yields are significantly lower if the water shortage persists.


The sweet corn is pollinated exclusively by the wind. Some properties of the father variety are transferred to the grains of the sweet corn variety. So that your maize is not pollinated by agricultural varieties, there should be a distance of several hundred meters between your garden and the nearest maize field. The more the better. For the same reason, try to only grow one variety in your garden at a time. Plant the sweet corn in the garden in at least two parallel rows instead of in a single long row. In this way you ensure fertilization with the desired variety.

Harvest sweet corn

The right time to harvest has come when the grain threads have dried up brown-red and the sweet corn kernels have reached their final size. They should have their varietal color on the outside, but still be soft on the inside. This stage is also called milk maturity. The ripeness can be easily checked: Carefully remove the husks of the corn on one side and scratch off a few grains with your fingernail. This method allows the cob to continue to ripen if necessary. Milk ripening is reached for early varieties in late July or early August. To harvest, you can simply twist off or break the cobs off the plants and leave the rest until autumn. The stems and leaves dry out by autumn and can then be composted. Alternatively, you can cut the plants close to the ground. Shred stems and leaves with the garden shredder and use as mulch material in the garden.

The corn from sweet corn is rich in vitamins and minerals such as potassium and magnesium. It contains over three percent protein and up to 15 percent sugar. However, fresh corn cobs cannot be stored for long and should best be consumed fresh. Boil the flasks in salted water for about five minutes. As is customary in the USA, they are eaten with salty butter or peanut butter spread straight out of the hand. You can also grill corn on the cob or remove the cooked kernels from the cob and make a salad with cucumber and paprika. In addition, blanched corn on the cob can also be frozen and eaten at a later point in time. Since sweet corn does not contain gluten, it is a welcome alternative to other grains.

Variety tips

For cultivation in your own garden, you should choose early varieties, as these ripen better in our latitudes. Variety designations with "extra sweet / super sweet" in the name promise a particularly intense aroma.

  • ‘Golden Bantam’ is one of the best-known types of sweet corn. The grains should be consumed as freshly picked as possible, as the sugars are quickly converted after harvest. ‘Golden Bantam’ was bred as the first yellow sweet corn variety in Philadelphia (USA) in 1902. It is characterized by large cobs and grains with a good bite.
  • ‘Damaun’ is an early and very sweet variety of corn. When sown from the beginning of May, it produces relatively thick cobs as early as the end of July.
  • ‘Hookers Sweet Indian’ is an early variety with colorful corn kernels.
  • ‘Mezdi’ matures after 90 to 100 days. The first corn on the cob can be harvested from the beginning of August.
  • ‘Tramunt’, on the other hand, is a late and very sweet variety. It ripens from mid-August to October.
  • Black Aztec is a late variety that sports almost black kernels of corn.
  • ‘Rangold’ carries sweet flasks with golden yellow grains and a few rows of grains.

Diseases and pests

The grains of sweet corn are extremely popular with various species of birds. In late summer, they often expose the tips of the pistons to get at the nutritious grains. This can be prevented by simply pulling tangerine nets or thin cloth bags over the flasks. The young plants in the garden must above all be protected from the voracious snails. In agriculture, the European corn borer, a butterfly, is a feared pest. The caterpillars of the pest mine in the cob or stem of the maize plant. Fortunately, an infestation in the garden is rare. As soon as you discover caterpillars of the European corn borer, you should dispose of the infected corn plant completely in the organic waste. Then check the other specimens regularly to prevent further spread.