The history of vegetable growing dates back more than 10,000 years in Maryland, when the Piscataway and other native tribes did well growing beans, maize and squash in the area's rich soil. Today commercial growers and home gardeners continue to do well growing corn, the modern version of maize, and other vegetables that create a bounty that peaks in July and August each summer.
Commercial growers harvest an average of 5,000 acres of sweet corn annually, with a value of $8 million, according to the Maryland Cooperative Extension. Home growers with large gardens can also grow sweet corn. Recommended yellow corn varieties include Sundance, Showcase and Supersweet 7210, while white varieties such as Ice Queen, Sweet Ice, Alpine and Fantasia win plaudits. Plant early varieties around April 1 to 10 about 1 to 1 ½ inches deep in the soil. Main-season sweet corn can be planted between April 20 and June 1. While the planting season can be extended to the beginning of July, corn planted after mid-May may experience more serious problems with pests.
Many varieties of tomatoes grow well in Maryland, from Tiny Tim cherry tomatoes to Pruden's Purple heirloom, as well as more common varieties such as Early Girl, Better Boy, Roma, Patio, Supersonic, Beefsteak, Celebrity, Rutgers and Yellow Pear. Start seeds in mid-March and transplant seedlings between May 1 and 15.
Popular in August at roadside stands throughout the state, the watermelon does especially well on Maryland's Eastern Shore. Commercial growers raise both standard and ice-box types, typically planting 2,500 acres per year. These varieties produce well, according to the Maryland Cooperative Extension: Royal Jubilee, Crimson Sweet, All Sweet, Sangria, Royal Majesty, Jubilee and Sugar Baby. Watermelons need to be well-weeded and rotated in the garden to avoid disease. Extension experts recommend planting watermelon from seed between May 1 and May 15, and if possible, through black plastic mulch that covers the ground.
With 2,300 market acres planted, snap beans produce well in Maryland given their early maturity of just 75 to 85 days. Home gardeners also benefit from the high productivity per plant of snap beans, harvested when seeds in the pods are just a quarter of full size. Plant from seed after danger of frost is past, generally around May 1 to 15 in much of the state. The Jade and Kentucky Blue varieties of snap bean grow well. For a continuous harvest, plant every two weeks until mid-July.