Ever wondered how many corn seeds per hole should you plant? Corn, or maize, has been cultivated for centuries. Its history stretches back nearly 10,000 years to southern Mexico.
Selective breeding through hundreds of generations turned the wild teosinte grass with its small grains into the sweet, buttery, and rich food we know today. As corn is wind-pollinated, it is better planted in blocks, and not the rows you might use for other vegetable crops.
My preference is to plant 2 seeds per hole, in case one doesn’t germinate. You can plant up to three per hole if you want to be extra cautious and are happy to thin them back more.
Sweetcorn is easier to grow than many people think, although it can be quite susceptible to cold and rot. For me, the only downside is that it wants more than its fair share of space.
However, it's completely worth it to experience the taste of corn fresh from the garden. Aside from this, corn requires surprisingly little care in comparison to some garden crops.
But you should know what to watch out for and the pitfalls to avoid when planting it. Read on for my best advice.
Sunshine and Heat
Corn absolutely needs sunshine and should be planted among the warmest months if you are in a cooler climate. Usually, May to June should suffice, but it can be earlier or later in the year in warmer climates.
Soil temperatures should be at least 60 degrees Fahrenheit. Plant corn in a spot that receives a lot of sunlight. Corn absolutely cannot do without at least six hours of direct sunlight per day.
Corn loves highly fertile, well-drained soil with a pH of 6 to 6.8. It can be a bit fussy about water levels. You need to keep it continuously moist, but ensure that the soil has good drainage.
Corn needs a huge amount of nitrogen, so keep this in mind when choosing a fertilizer. Compost and well-rotted manure have high nitrogen levels, so they are very suitable for corn growth.
As mentioned earlier, corn fares better when planted in a “block,” rather than in rows. This is common wisdom that you’ll find in any guide. And corn has been around forever, so we’ve had plenty of time to experiment.
This means that rather than lining up 2 long single-file rows of corn in your garden, you plant them in one block together. So, if planting 12 seeds, create 3 rows of 4, not 2 rows of 6.
Plantlings should be spaced about 15 inches apart and rows 35 inches apart. This will take up more space in your garden but will lead to greater cross-pollination.
Cornflowers are pollinated directly by wind and not any other agent, like bees. So this gives them a higher chance of developing full, viable ears.
Dig a small hole about 2 inches into the soil at each point in the block. If 2 seeds sprout, thin back one and leave the strongest to grow.
Corn earworms are one of the most common pests for sweetcorn. There are a couple of strategies to deal with them.
The first is to spray mineral oil or garlic water onto the corn. Wait until the corn's silk appears and spray directly onto it. This should prevent earworms from damaging the tips.
Another method is to “trick” the corn into growing early, so they are harvested before the corn earworms appear in the season.
Lay down clear film or plastic above the soil. This warms the earth to the correct temperature about 20 days early. Remove it no more than thirty days later. This trick helps you avoid damage from earworms.
Other insects to watch out for when growing corn include cucumber beetle larvae, seed-corn maggots, and cutworms. Check what threats you may have in the area and apply the correct natural pesticide accordingly.
Signs of Disease
The best defense against disease in corn is to have clean garden practices, rotate your crops, and plant disease-resistant hybrids. If you see signs of disease in corn, you need to deal with it immediately before it spreads.
Anthracnose is a common fungus affecting corn. Signs include discolored spots of yellow, purple, or brown on the leaves and sunken, dark spots on stems. You might also see gelatinous mass and rotting.
Destroy infected plants immediately and ensure the crop is not being overwatered or drained improperly. Also look out for pale, shining galls on the corn.
This is corn smut, another fungus, and these galls will burst and release black spores. Cut them off and dispose of them before this happens. If a plant is badly affected, you need to destroy or bin the whole plant.
Do not add them to your compost heap. These fungi can stay viable for a long time.
Proper weeding is essential as the corn plants cannot compete with these unwanted visitors. Weeds sap nutrients from the soil that corn needs.
Ensure there are no weeds at the time of planting. If any appear, remove them gently as corns have very delicate root systems, so you risk damaging them in the process.
You want to harvest at the very peak of ripeness. Three weeks after the appearance of the corn silk, start testing them. To check, pull back part of the husk and press on a kernel with your thumbnail.
If it’s firm and contains a milky liquid, they are ready. If the silk is completely dry or a faded yellow-green, the corn is past the peak point of ripeness.
Sweet corn is best eaten on the day of harvest as it will start to lose its sweetness immediately. If not eaten, you can blanch or freeze it on the day to retain the flavor at its freshest.
With 2-3 seeds planted per hole, and the rest of these care instructions followed, you can grow beautiful ears of corn that will have everyone smiling around the dinner table.
There really is nothing like eating corn on the cob fresh from the garden. Between pests, disease, and a short ripening window, it can feel that a lot can go wrong with corn.
But with some care and attention, it can be quite a low-effort crop to produce. Before you know it, you’ll be enjoying your yield with nothing but some fresh butter and a grind of salt.