WHEN TO PLANT CUCUMBERS

• Cucumber plants should be seeded or transplanted outside in the ground no earlier than 2 weeks after the last frost date. Cucumbers are extremely susceptible to frost and cold damage; the soil must be at least 70ºF for germination. Do not plant outside too soon!
• To get a head start, sow cucumber seeds indoors about 3 weeks before you plan to transplant them in the ground. They like bottom heat of about 70ºF (21ºC). If you don’t have a heat mat, put the seed flat on top of the refrigerator or perch a few on top of the water heater.

CHOOSING AND PREPARING A PLANTING SITE

• Select a site with full sun. Cucumbers need warmth and lots of light. 
• Cucumbers require fertile soil. Mix in compost and/or aged manure before planting to a depth of 2 inches and work into the soil 6 to 8 inches deep. Make sure that soil is moist and well-drained, not soggy and compacted.
• Soil should be neutral or slightly acidic with a pH of around 6.5 to 7.0.
• Improve clay soil by adding organic matter. Improve dense, heavy soil by adding peat, compost, or rotted manure. (Get a soil test if you are unsure of your soil type; contact your local county cooperative extension.) Light, sandy soils are preferred for northern gardens, as they warm quickly in the spring. See our guide to soil amendments.

HOW TO PLANT CUCUMBERS

• Plant seeds 1 inch deep and about 2 to 3 feet apart in a row, depending on variety (see seed packet for details). For vines trained on a trellis, space plants 1 foot apart.
• Cucumbers can also be planted in mounds (or “hills”) that are spaced 1 to 2 feet apart, with 2 to 3 seeds planted in each mound. Once plants reach 4 inches in height, thin them to one plant per mound. 
• If you live in the cooler climates, you can help warm the soil by covering the hill or row with black plastic.
• After planting, mulch around the area with straw, chopped leaves, or another organic mulch to keep pests at bay, and also keep bush types off the ground to avoid disease.
• A trellis is a good idea if you want the vine to climb, or if you have limited space. Trellising also protects the fruit from damage from lying on the moist ground. See how to build a trellis and support for vining vegetables.
• Cover freshly planted cucumber seeds with netting or a berry basket if you have pests; this will keep them from digging out the seeds.