Loosen the soil at the base of the pergola to a level of 8 to 10 inches. Mix 5-10-10 fertilizer with the soil, at a rate of 3 lbs. for every 100 square feet of planting space.
Dig planting holes just deep enough to set the young cucumber plants at the level they were growing in their containers. Make the holes approximately 4 inches from the base of the pergola and leave a space of 8 inches between each plant.
Water the cucumber plants deeply after planting. Continue to provide regular moisture when rainfall measures less than 1 inch in a one-week period.
Add a 2- to 3-inch layer of mulch around the plants to prevent weeds and seal in moisture.
Snip off the first four side runners that form at the base of each plant to increase the number of cucumbers produced.
Examine the vines once or twice each week and gently drape them over the pergola so that they will climb the structure as they grow.
Harvest the cucumbers when they reach the desired size. Keep in mind that smaller cucumbers tend to be more crisp and tender.