Cucumbers are vegetables that grow on creeping vines and are members of the gourd family. The largest varieties can reach up to two feet long. The greenhouse cucumber, commonly grown in the United States, is a seedless variety that does not require pollination. Pollination can alter the flavor and shape of the vegetables.
Choose the European seedless cucumber seed for planting in a greenhouse. The germination rate of seedless cucumbers is close to 100%.
Treat the soil in the main production area a few weeks before you transplant the cucumber seedlings. According to the Kansas State University Extension Office, you should apply 50 pounds of nitrogen, 150 pounds of phosphorus and 250 pounds of potassium per acre of soil. This will supply the cucumber plants with all the nutrients they need.
Plant one cucumber seed per container. Use 2- or 4-inch pots. Push each seed down into the potting soil or rock wool. Rock wool is a growing medium that is made from rock and sand melted together and spun into fibers.
Water the plants once a week to keep the soil moist. Do not allow the soil to become dry as this can kill the plants. Test the soil daily and water the cucumbers more often if necessary.
Maintain a greenhouse temperature of 75 to 85 F. This will encourage quick germination (within 2 to 3 days).
Transplant the seedlings once they have 3 or 4 leaves. This should occur 2 to 3 weeks after sowing. At this point the plants should be moved to a main production area in the greenhouse and kept at a temperature of around 77 F.
Plant the cucumber plants approximately 2 feet apart and in rows that are 2 feet apart. Use a trellis or a wire system to train the plants to climb. This will keep the cucumbers off of the ground and help prevent disease. It will also help make the cucumbers easier to harvest.
Prune the plants using the umbrella method. This method leaves one main shoot up the middle with two side shoots coming off the main shoot towards to top of the plant. This leaves a shape like an umbrella, evening out the cucumber's growth on each side of the plant and distributing the weight evenly.
Harvest the cucumbers when they have filled out and their sides are slightly ribbed. Most mature cucumbers will weigh approximately 1 pound. Cucumbers can be stored for a few days in the refrigerator when wrapped in plastic wrap.