Buy Eureka cucumber seeds from a local nursery, gardening center or seed catalog. One seed packet is adequate for most home vegetable gardens.
Prepare the garden soil in early spring after all danger of frost has passed. Seeds will not germinate in cold soil and will die if left out in a late frost. Cucumbers require large surface space for optimal vine growth. Choose a site with full sun exposure, sheltered from high winds if possible. Till soil until it becomes loose and well-draining. Work in compost or well-rotted manure for added nutrients and better growth.
Plant Eureka cucumber seeds in the prepared site. Sow seeds 1 inch deep. Frequently water the soil, ensuring a moist environment for seed germination. Once seedlings become established, thin plants to one cucumber plant every 12 inches in rows at least 3 to 5 feet apart.
Install black plastic mulching if planting seeds in the spring to retain soil moisture and warmth. This increases early production. Apply a nitrogen fertilizer after cucumbers begin to vine. Continue to provide plenty of water, especially when cucumbers begin setting. Lack of adequate moisture stunts growth and overall production.
Harvest cucumbers once they reach usable size for your needs. Eureka cucumbers reach maturity an average of 57 days after sowing seeds. Continue picking cucumbers throughout the remainder of the growing season to ensure vitality. Delaying harvest results in poor cucumber production and reduced quality.