Spread 4 to 5 inches of compost over a garden bed that receives full sun. Work the compost into the top 8 inches of soil using a tiller, spade or hoe.
Sow the seed corn after all danger of frost is passed in spring. Plant the seeds two inches apart for miniature corn, and not at the spacing recommended on the seed packet. Space the rows 30 inches apart.
Water the bed as necessary so it remains evenly moist, both before and after the corn germinates. Corn typically requires 1 to 2 inches of water a week from rain or irrigation.
Apply 1 lb. of 21-0-0 fertilizer to each 100-foot row once the plants are 6 inches tall. Spread the fertilizer on the soil surface six inches from the base of the cornstalks and water thoroughly after application. Fertilize a second time when the plants are 2 feet tall.
Harvest baby corn one to three days after the corn silks become visible at the top of the developing ear husk and once the ears are 1 to 2 inches long. Cut the entire ear off the plant with a sharp knife. Harvest daily once the first ears are ready, as not all miniature corn ears develop at the same time.