How to Plant Cucumber Seeds – All the Best Tips

Summer salads wouldn’t be the same without homegrown cucumbers to load them with sweet, cool crunch. Knowing how to plant cuke seeds lets you grow far more varieties than relying on started plants from your garden store. It also guarantees your cukes get the best care from the minute their first tiny stems pop out of the soil.


When’s The Right Time to Plant?

Plant your cuke seeds outdoors after the soil temperature is consistently above 65°F (18.3˚C). If you’re starting them indoors, do it four to six weeks ahead of your last average spring frost date.

Where Is the Best Place to Plant?

Cucumbers need at least six hours of daily sun. For indoor plants, that means a large south-facing window. Outdoors, planting your seeds in rows angled toward the noontime sun gives them maximum sun exposure.

What Kind of Soil Do They Need?

Cucumbers do best in loose, well-draining organically enriched soil. If necessary, work a 2-inch layer of organic fertilizer or compost into your garden soil one month before planting your seeds. Plant your indoor seeds in a soilless seed-starter mix. A good starter mix recipe includes equal parts of:

  • Vermiculite or perlite
  • Organic compost
  • Milled sphagnum moss

What about Spacing?

For easy transplanting, plant your indoor seeds in individual, 4-inch peat pots. Poke two evenly spaced holes into the centers of the pots with your finger and drop a seed in each. When the seedlings have two sets of true leaves, cut the weaker one in each pot off at its base.

What’s the Outdoor Seed-Planting Process?

Mound freshly tilled soil into rows 4 to 6 inches high. Space multiple rows 6 feet apart for sprawling cucumbers or 3 feet apart for trellised ones. Dig 1½-inch-deep holes 6 inches apart along the length of each row, drop in your seeds hole and cover them with soil.

Expert gardener’s tips:

  • Once all your seeds are planted, gently tamp the soil over them to remove air pockets. Then sprinkle the rows with water to moisten them without disturbing the seeds.
  • Now is the time to trellis your cukes. Doing it after the seeds have sprouted could damage their fragile root systems.

How Long Will It Take My Seedlings to Appear?

If your soil temperature is between 65° and 80° F (18.3° and 26.6°C), your seeds will need at least 10 days to sprout. If it’s between 80° and 90°F (26.6° to 32.2°C), they could begin sprouting in as little as three days.