How to Grow Cucumbers From Seed

Cucumbers are warm-weather plants that sulk in cold soil, so wait for real warmth before you sow. Direct-sow seeds outdoors 1 to 2 weeks after your last frost, once the soil has reached at least 65 to 70F. In cool-summer regions you can start seeds indoors 3 weeks early in peat or paper pots, since cucumbers hate having their roots disturbed. For a steady supply, sow a second short round about 4 weeks after the first.

Cucumbers grow fast once the ground is warm. Sow the seeds about half an inch to one inch deep in rich, well-drained soil in full sun, either along a trellis or in small hills of 3 to 4 seeds. Keep the soil evenly moist at 70F or above and seedlings appear in 7 to 10 days. Thin to the strongest plant every 12 inches, and give vining types a trellis so the fruit hangs straight and clean.

Cucumbers are thirsty and hungry. Give them a deep, steady inch or two of water a week and mulch to hold moisture, because uneven watering is what turns cucumbers bitter and misshapen. Feed with a balanced fertilizer when they start to vine and again as they set fruit. In hot, humid regions like the Southeast, watch for powdery mildew and cucumber beetles: water at the base to keep leaves dry, and grow a resistant variety like Marketmore. Where summers are short, such as the northern Midwest or New England, start seeds indoors and use black plastic or a trellis in a warm, sheltered spot to make the most of the season.

Cucumbers climb happily alongside plants that repel their pests or draw in pollinators, which matters because every cucumber needs a visited flower. These four make especially good neighbors, and you can add any of them in one click:

Pick cucumbers young and often. Slicing types are best at 6 to 8 inches long and still firm and green, while pickling types are picked at 2 to 4 inches. Cut them off with a snip rather than pulling, and check the vines every day or two at peak season. The more you pick, the more the plant produces, so never let a fruit turn yellow and fat on the vine or the whole plant slows down.

Cucumbers are at their best raw and cold. Slice them into green salads, layer them on sandwiches, or toss them with vinegar, dill, and onion for a quick cucumber salad. Blend them into chilled soups or add a few slices to a pitcher of water. Pickling varieties turn into crisp dill or bread-and-butter pickles, and even slicing cucumbers make good refrigerator pickles when picked small.

• Bitter fruit: caused by heat and uneven watering. Water deeply and regularly, mulch the roots, and harvest young.
• No fruit or fruit that shrivels: usually poor pollination. Plant flowers nearby to draw in bees, or hand-pollinate on cool, cloudy mornings.
• Powdery mildew: a white coating in warm, humid weather. Water at the base, space plants for airflow, and grow a resistant variety like Marketmore.
• Cucumber beetles: yellow-and-black beetles that chew leaves and spread wilt. Use row cover until flowering, then remove it so pollinators can reach the blooms.