Planting and Growing Cucumbers

Cucumbers are an easy-care vegetable that thrives in the sun and water, and will grow consistently as long as they receive consistent watering and warmth. To avoid a bitter taste, make sure to not let cucumbers get too large before you pick them. There are two types of cucumber plants: vining cucumbers and bush cucumbers. The most common varieties, vining cucumbers grow on vigorous vines shaded by large leaves whereas bush cucumbers are nicely suited to containers and small gardens.

For an early crop, sow cucumber seeds indoors about 3 weeks before you plan to transplant them into the ground. Provide bottom heat of about 70°F with a heating pad or place the seed flats on top of a refrigerator or water heater. Cucumber plants should be seeded outdoors or transplanted outside in the ground no earlier than 2 weeks after the last frost date. Bear in mind that cucumbers are heavily susceptible to frost and cold damage. The soil must be at least 70°F for germination; seedlings also set best at that temperature. In cooler climates, warm the soil by covering it with black plastic. For continued harvests through the season, make successive plants (every 2 weeks). In warm soil, cucumbers will grow quickly and ripen in about 6 weeks.

Select a site with full sun as cucumbers need warmth and lots of sunlight. Soil should be moist but well-draining (not soggy) and warm, and should be neutral or slightly acidic with a pH of around 6.5 to 7.0. Plant seeds 1 inch deep and about 3 to 5 feet apart in a row, but it all depends on the variety. 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. Thin them to one plant per mound once plants reach 4 inches in height. In cooler climates, the soil can be warmed prior to planting 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 away, and also keep bush types off the ground to avoid disease.

Once seedlings emerge, begin to water frequently, especially because the main care requirement for cucumbers is consistent watering. They need at least one inch of water per week (or more if temperatures are particularly high) as inconsistent watering leads to bitter-tasting cucumber. It is best to water slowly in the morning or early afternoon, and avoid getting the leaves wet, as that may encourage lead diseases that can ruin the plant. If possible, water your cucumbers with a soaker hose or drip irrigation to keep the foliage dry. To retain moisture, mulch around plants. If pests appear, cover young plants with row covers or berry baskets. When seedlings reach 4 inches tall, thin plants so that they are at least 1½ feet apart. If you have limited space or would prefer vertical vines, set up trellises early to avoid damage to seedlings and vines. To attract bees and set more cucumbers, spray vines with sugar water.

Cucumbers require fertile soil. Before planting, add about 2 inches of aged manure and/or compost to the bed and work it in to a depth of 6 to 8 inches. If you worked organic matter into the soil before planting, you may only need to side-dress your plants with compost or well-rotted manure sparingly. Otherwise, fertilize the plants with a liquid 5-10-10 fertilizer, and apply 1 week after the plant starts blooming and every 3 weeks thereafter directly to the soil around the plants. Another option is to work a granular fertilizer into the soil. Make sure to not over-fertilize or the cucumbers will get stunted.

If you let cucumbers get too large, they will taste bitter. At peak harvesting time, it’s necessary to pick cucumbers every couple of days because they grow quickly. Harvest regular slicing cucumbers once they reach 6 to 8 inches long. Harvest dills at 4 to 6 inches long and pickling cucumbers at 2 inches long. The large burpless cucumbers can be up to 10 inches long and some types are even larger. Cucumbers are best picked before their seeds become hard and are eaten when immature. Make sure they don’t get yellow; a cucumber is of the highest quality when it’s crisp, firm, and green. Cucumbers will get tough skins and lower plant productivity when left on the vine for too long. Use a knife or clippers to cut the stem above the cucumber as pulling the cucumber may damage the vine. Make sure to keep them picked, and if you don’t, they will stop producing as they mature.