How to grow cucumbers in your garden

Plant cucumbers outdoors one to two weeks after your last frost, once the soil has warmed to at least 65°F (18°C). Sow seeds 1 inch (2.5 cm) deep in full sun and rich soil. Grow them up a trellis to save space and keep the fruit clean. Give them a deep soak, about 1 to 2 inches (2.5 to 5 cm) a week, so the soil never dries out. Most cucumbers are ready 50 to 70 days after sowing. Once they start, pick every day or two.

Cucumbers grow fast. A healthy vine can go from flower to a full-sized cucumber in about a week and a half. Check the vines often once the flowers open.

Choose a type of cucumber

Pick the type based on how you plan to eat it.

• Slicing cucumbers are long and smooth, for salads and sandwiches. ‘Marketmore 76’ is an old favorite with good disease resistance.
• Pickling cucumbers are short and bumpy, with thin skins that soak up brine. ‘Boston Pickling’ is a classic.
• English or long seedless cucumbers have thin skin and few seeds. ‘Telegraph Improved’ grows well on a trellis.
• Lemon cucumbers are round, yellow, and mild.
• Bush types like ‘Spacemaster’ grow short vines for pots and small beds.

Some cucumbers, such as ‘Diva’, set fruit without pollination. They are a good pick for greenhouses and tunnels, where bees cannot reach the flowers.

If you want something different, cucamelons are a related vine with grape-sized fruit that taste like cucumber with a hint of lime.

Sow outside or start indoors

Direct sowing is the easiest way. Cucumbers do not like their roots disturbed, and seeds sown in warm soil sprout in 3 to 10 days.

Wait for warm soil. Seeds sown in cold, wet soil rot before they sprout. Check with a soil thermometer, or use my soil temperature chart for vegetables.

In a short season, start seeds indoors three to four weeks before you plan to plant out. Use pots that go into the ground whole, such as peat-free paper pots or soil blocks. Harden them off for a week, then plant without breaking up the root ball. Older seedlings struggle after transplanting, so do not start them too early.

How to space cucumbers

On a trellis, sow seeds 6 inches (15 cm) apart along the base. Thin to one plant every 12 inches (30 cm) once they have true leaves.

On the ground, plant in small mounds, or hills. Sow four or five seeds per hill and thin to the two strongest. Space hills 3 to 4 feet (90 to 120 cm) apart.

Thin by snipping extra seedlings at the soil line. Pulling them can tear the roots of the plants you keep.

Grow cucumbers on a trellis

A trellis is the best thing you can do for cucumbers. The fruit hangs straight, stays clean, and is easy to spot. Air moves through the leaves, which cuts down on disease. And a vine that would sprawl across a whole corner of the garden fits in a narrow strip.

Use a sturdy support about 5 to 6 feet (1.5 to 1.8 m) tall. A cattle panel, wire mesh, or strong netting all work. Set it up before you sow. My post on wire trellises shows simple options, and my guide to raised bed gardening shows how to fit one into a bed.

Guide young vines toward the trellis for the first week or two. After that, the curly tendrils grab on and climb.

Sun, soil, and fertilizer

Cucumbers need full sun, at least six to eight hours a day. They grow best in loose soil rich in compost, with a pH between 6.0 and 7.0.

Mix 2 inches (5 cm) of compost into the bed before planting. Feed again with compost or a balanced vegetable fertilizer when the vines start to run, and once more when the first flowers open. Too much nitrogen gives you lots of leaves and few cucumbers.

How to water cucumbers

Cucumbers are full of water, and the plant needs a steady supply. Water at the base with a deep soak, about 1 to 2 inches (2.5 to 5 cm) a week, more in hot weather. Water in the morning so the leaves dry by evening.

Dry spells cause bitter, misshapen fruit. A soaker hose or drip line keeps the soil moist without wetting the leaves. See my posts on how to use a soaker hose and drip irrigation systems.

Once the soil is warm, add a layer of straw mulch. It holds in moisture and keeps fruit off the dirt.

Flowers but no cucumbers

This worries a lot of new gardeners, and it is normal at first. Cucumber vines make male flowers first, often a week or two before any female flowers. Male flowers drop off after they shed pollen.

Female flowers have a tiny cucumber behind the petals. Bees carry pollen from male flowers to female flowers. If the tiny cucumbers turn yellow and shrivel, pollination failed.

To help, plant flowers nearby to draw bees. My post on planting a pollinator garden has ideas. You can also pollinate by hand. In the morning, use a small, soft brush to pick up pollen from the center of a male flower. Dab it into the center of a female flower.

Common cucumber problems

Cucumber beetles are small yellow beetles with black stripes or spots. They chew leaves and spread bacterial wilt, a disease that makes whole vines collapse. Cover young plants with floating row cover. Take it off when flowers open, so bees can get in.

Powdery mildew shows up in late summer as white powder on the leaves. Grow resistant varieties, give plants room for air to move, and water the soil, not the leaves.

Yellow leaves have several causes. My post on cucumber leaves turning yellow walks through each one.

For good neighbors in the garden, see my list of companion plants for cucumbers.

When to pick cucumbers

Pick cucumbers young. Size depends on the type:

• Slicing cucumbers at 6 to 8 inches (15 to 20 cm).
• Pickling cucumbers at 2 to 4 inches (5 to 10 cm) for pickles.
• English cucumbers at 10 to 14 inches (25 to 35 cm).

Cut them off with scissors or pruners and leave a short stem. Pulling can damage the vine.

Check the plants every day or two in midsummer. A big yellow cucumber left on the vine signals the plant to slow down. Keep picking and the vine keeps producing.

Store cucumbers in the fridge and eat them within a week. They go soft fast.

Growing cucumbers in pots

Bush cucumbers grow well in containers. Use a pot that holds at least 5 gallons (19 L) of potting mix, and bigger is better. Add a small trellis or tomato cage for support. Pots dry out fast, so expect to water every day in hot weather. My list of easy vegetables to grow in pots has more ideas for a patio garden.

Save cucumber seeds

To save seeds, let one cucumber stay on the vine until it turns yellow or brown and feels hard. Use an open-pollinated variety, not a hybrid. My guide on how to save cucumber seeds explains the fermenting and drying steps.