Cucumbers grow fast and produce heavily once they get going, which makes them one of the most satisfying summer crops. They are warm-season vines that need warm soil, full sun and plenty of water. Grown up a trellis, they take little bed space and give straighter, cleaner fruit. This page covers when to sow, how to space and support them, how to water and feed them, and the problems you are most likely to meet.
Cucumber at a glance
| Type | Vegetable |
|---|---|
| Season | Warm-season |
| Sun | Full sun |
| Plant spacing | 12 in |
| Row spacing | 48 in |
| Per square foot | 2 |
| Seed depth | 1 in |
| Days to maturity | 50–70 from seed |
| How to start | Direct sow after last frost, or indoors 3–4 weeks before |
| Water | 1.5 in per week |
These are the same numbers our plant spacing, square foot and harvest date calculators use. See every crop in the plant database.
When to plant cucumbers
Cucumbers are tender to frost and rot in cold soil. Sow seeds directly outdoors 1 to 2 weeks after your last spring frost, once the soil has reached at least 65°F. For an earlier crop, start seeds indoors 3 to 4 weeks before the last frost in individual pots, because cucumbers dislike root disturbance.
Look up your last frost with the frost dates by ZIP code tool. For a steady supply until fall, sow a second batch 4 to 6 weeks after the first; the succession planting planner works out the dates.
How to plant cucumbers
- Choose full sun. At least 6 to 8 hours of direct sun.
- Enrich the soil. Cucumbers are hungry. Mix 2 to 3 inches of compost into the bed before sowing.
- Sow 2 or 3 seeds per spot. Plant 1 inch deep and thin to the strongest seedling at the spacing in the table above.
- Put up a trellis at sowing time. A 5 to 6 foot trellis or fence keeps fruit off the ground and improves airflow. The trellis post and wire calculator lists the materials. Bush varieties suit containers and small beds.
- Count your plants. Two or three plants usually feed a family. Use the plant spacing calculator to fit them to your bed.
Caring for cucumbers
Cucumbers are mostly water, and dry spells make them bitter and misshapen. Give 1 to 2 inches a week, more in hot weather, and water at the base in the morning so leaves dry quickly. Mulch keeps the soil cool and moist and keeps fruit clean. The garden watering calculator turns the weekly amount into gallons.
Guide vines onto the trellis for the first week or two; after that, tendrils grip on their own. Side-dress with compost or a balanced fertilizer when vines start to run and again when flowering begins. The first flowers are usually male and drop off without fruit; female flowers, with a tiny cucumber behind them, follow a week or so later.
Companion plants
| Grow nearby | Beans, peas, radishes, dill, nasturtiums, sunflowers |
|---|---|
| Keep apart | Potatoes (heavy competition for water); melons and squash right beside them share pests and mildew |
Beans and peas add nitrogen. Radishes and nasturtiums are said to deter cucumber beetles, and dill and sunflowers draw in pollinators and beneficial insects. Check other pairings with the companion plant finder.
Common problems
| Problem | What you see | What to do |
|---|---|---|
| Cucumber beetles | Yellow beetles with black stripes or spots chewing leaves and flowers | Cover young plants with row cover until flowering, and hand-pick beetles. They spread bacterial wilt, so control them early. See the pest identifier. |
| Bacterial wilt | Whole vines wilt suddenly and do not recover overnight | No cure. Pull and bin wilted vines, and control cucumber beetles next season. |
| Powdery mildew | White, dusty patches on the upper leaves in mid to late summer | Grow resistant varieties, trellis for airflow and water at the base. Remove the worst leaves. |
| Bitter fruit | Cucumbers taste bitter, especially near the stem end | Caused by heat and drought stress. Water deeply and evenly and mulch. |
| Misshapen or shriveled fruit | Fruit is curved, pinched or yellows and drops while small | Usually poor pollination or uneven water. Plant flowers nearby for bees and keep moisture steady. |
Not sure what you are looking at? The plant problem identifier ranks likely causes from the symptoms you see, and our guide to growing cucumbers goes into more detail.
When and how to harvest
Pick cucumbers young and often. Slicing types are best at 6 to 8 inches, pickling types at 2 to 4 inches, and specialty types at the size on the seed packet. Fruit should be firm and evenly green. Yellowing means it is overripe, and leaving it on the vine tells the plant to stop producing.
At peak season, check every day or two. Cut fruit off with scissors rather than pulling, which can damage the vine. Store unwashed cucumbers in the fridge and use them within a week. Use the harvest date calculator to see when your first fruit should be ready.
Plan your cucumbers
- Plant spacing calculator: how many plants fit your bed
- Planting calendar: sowing and transplant dates for your frost dates
- Frost dates by ZIP code: your last spring and first fall frost
- Harvest date calculator: when your crop will be ready
Frequently asked questions
How far apart should I plant cucumbers?
Space cucumbers 12 inches apart in rows 48 inches apart. In a square foot garden, plant 2 per square foot.
How deep do I plant cucumber seeds?
Sow seeds 1 inch deep. Sow 2 or 3 seeds per spot and thin to the strongest seedling.
How long do cucumbers take to grow?
Most varieties are ready 50–70 days from seed. Check the seed packet, because early and late varieties differ.
How much water do cucumbers need?
About 1.5 inches of water a week, from rain and watering combined. In hot weather they may need more. Steady moisture prevents bitter, misshapen fruit.
Do cucumbers need a trellis?
No, but vining cucumbers grown up a trellis take less space, stay cleaner and suffer less disease. Bush varieties can grow without support.
Why are my cucumber flowers falling off?
The first flowers are male and drop off naturally. Female flowers, with a tiny cucumber at their base, appear about a week later and need bees to pollinate them.