Why do my cucumber plants have lots of flowers but no fruit?

This is usually a pollination issue. Cucumber plants produce separate male and female flowers. The male flowers appear first. If you see flowers but no tiny cucumbers behind them, those are male flowers. Female flowers have a small, swollen ovary at their base that looks like a miniature cucumber. If female flowers are present but not developing, it means they aren't being pollinated. You can encourage pollinators by planting flowers nearby or hand-pollinate using a small paintbrush to transfer pollen from a male flower to a female flower.

Why do my cucumbers taste bitter?

Bitter cucumbers are typically the result of plant stress, most often from inconsistent watering or extreme heat. The stress causes the plant to produce higher levels of cucurbitacins, a natural compound that causes the bitter taste. To prevent this, water consistently and deeply, and use mulch to regulate soil temperature and moisture.

How to Grow Cucumbers: Bush & Vining Types

Cucumbers are a fast-growing, productive crop perfect for summer gardens. Whether you prefer them for slicing, pickling, or snacking, growing your own provides unparalleled freshness.

Planting & Spacing

When to Plant

Cucumbers are very sensitive to cold. Plant seeds or seedlings outdoors only after all danger of frost has passed and the soil is at least 70°F (21°C). For an earlier start, you can sow seeds indoors in peat pots 3-4 weeks before your transplant date.

Pro Tip for Desert Gardeners (Mesa, AZ): Take advantage of a second growing season by planting cucumber seeds directly in the garden in late August or early September. They will thrive in the late summer heat and produce a great fall crop before the weather turns cool.

Sun and Soil

Provide a site with at least 6 hours of full sun and rich, well-drained soil. Cucumbers are heavy feeders; enrich the soil with plenty of compost or aged manure before planting.

Spacing and Support

Vining Types: These are best grown on a trellis or fence. This saves space, keeps fruit off the ground (preventing rot), and improves air circulation. Space plants 12 inches apart.
Bush Types: These are more compact and good for smaller gardens or containers. Space them 3 feet apart in all directions.

Watering & Care

Watering

Cucumbers are over 90% water and require consistent moisture to avoid becoming bitter. Provide at least one inch of water per week, and more during hot, dry spells. Water at the base of the plant to prevent leaf diseases.

Fertilizing

Side-dress your plants with a balanced, all-purpose fertilizer once they begin to develop runners and again when the first fruits appear.

Common Pests & Diseases

Powdery Mildew

This fungal disease appears as white, powdery spots on the leaves. It's common in humid weather. Prevent it by providing good air circulation (trellising helps) and watering at the soil level. A potassium bicarbonate-based fungicide can be effective.

Cucumber Beetles

These pests can damage plants and spread bacterial wilt. Use floating row covers to protect young plants. Remove the covers once the plants begin to flower so pollinators can reach them. Hand-picking the beetles is also an effective control in small gardens.

Harvesting

Harvest cucumbers when they reach the desired size for their variety. Don't let them get too large or they will become seedy and bitter. Harvest regularly—the more you pick, the more the plant will produce. Cut the stems with a knife or pruners rather than pulling the fruit, which can damage the vine.