To grow cucumbers in containers, start with large pots that can support both roots and vines. An 18-inch-diameter pot works well for vigorous cucumber plants. Fill the pot with a high-quality commercial potting mix formulated for use in containers. If you want to make your own mix, combine equal parts potting soil, compost and vermiculite, a mineral that helps retain moisture.

Plant three seeds 1 inch deep in the middle of each container. When seedlings have reached 4 inches tall, thin them to one seedling per container. If you're planting transplants, nursery-grown seedlings typically have more than one seed in the tiny pot.