Cucumbers are tender annuals that grow best in temperatures ranging from 60° to 90°F (15°-32° C).
- Sow cucumber seed in the garden or set out transplants 3 to 4 weeks after the average last frost date in spring.
- The ideal soil temperature for growing cucumbers is 70°F.
- Sow cucumber seed indoors as early as 6 weeks before transplanting into the garden.
- Protect cucumbers from unexpected frost or chilly nighttime temperatures early in the season. Use floating row covers or plastic tunnels to keep the chill away.
- Cucumbers require 55 to 65 frost-free days from sowing to reach harvest.
Where to Plant Cucumbers
- Grow cucumbers in full sun. Cucumbers can tolerate partial shade.
- Cucumbers prefer loose, well-drained soil rich in organic matter. Prepare planting beds in advance of planting by adding 2 to 3 inches of aged compost, commercial organic planting mix, and aged manure to beds. Turn the soil to 12 inches deep
- Place black plastic sheeting over the planting bed in spring to warm the soil in advance of planting.
- Cucumbers prefer a soil pH of 5.5 to 6.8. Cucumbers can tolerate alkaline soil to a pH of 7.6.
- Set trellises or supports in place to grow cucumbers up or mound the soil to create a small hill off which cucumber vines can run. Use a trellis 4 to 6 feet tall. Create a mound at least 16 inches across and several inches high; space mounds 4 to 6 feet apart.
Planting and Spacing
- Sow cucumber seeds 1 inch deep.
- Sow seeds at the base of the vertical support or on a mound at 6 to 8-inch intervals.
- When seedlings are 3 to 4 inches tall, thin to the strongest plant spaced 12 to 18 inches apart for vining cucumbers on vertical supports and 24 to 36 inches apart for bush varieties.
- Cut weak seedlings off at soil level with scissors to avoid disturbing the roots of remaining plants.
- Set a trellis, tripod, or cage in place at planting time if you are growing vining varieties. A 12 to 18-inch diameter wire cage is ideal for growing vining cucumbers. You can make a cage from a 4 to 5-foot section of wire fencing or construction mesh.
- To grow an early crop, you can start cucumbers indoors 2 to 3 weeks before the last frost in spring then transplant seedlings to the garden 2 to 3 weeks after the last frost.
Growing Cucumbers in Containers
Many dwarf or mini-cucumber varieties will grow in a pot as small as 6 inches wide and deep, larger is better. Check the description of the cucumber and its space requirements. 'Potluck' is a small growing variety. Larger cucumbers for containers include 'Patio Pik' and 'Bush Whopper.' Use a 12- to 18-inch trellis, stake, or other support to increase the yield of container-grown cucumbers.
- Keep the soil evenly moist with regular watering. Do not let the soil dry out. Cucumbers are about 95 percent water and require regular water for fast, even growth.
- Set a soaker hose or drip irrigation at the base of plants. Give cucumbers at least 1 inch of water each week during the summer.
- Always water at the base of plants. Moisture on cucumber leaves can result in fungal diseases such as powdery and downy mildew.
- Leaves may wilt in the afternoon in hot weather; that is because plants are taking up water faster than roots can supply.
- If plants are wilted in the morning, the soil is too try and needs immediate water.
- Mulch around plants to slow soil moisture evaporation and to avoid soil compaction caused by heavy watering.
- Too little water or inconsistent watering can cause cucumbers to become oddly shaped or bitter tasting.
- An easy way to measure soil moisture is to stick your index finger in the soil; if your finger comes away dry, it's time to water.
- Add aged compost or commercial organic planting mix to planting beds before planting. Compost has all the nutrients cucumbers need for fast growth.
- Side-dress cucumbers with compost tea or a dilute solution of fish or kelp emulsion or a liquid organic fertilizer every 10 to 14 days during the season.
- Feed cucumbers with low nitrogen, high phosphorus, and potassium formula. Be careful to follow label directions; over-fertilizing can stunt or harm plants.
- Side-dress cucumbers at midseason with aged compost to renew soil nutrients.
- Keep planting beds free of weeds; weeds compete for soil nutrients and water. Cultivate shallowly to avoid disturbing roots.
Caring for Cucumbers
- Mulch around cucumber plants with straw or chopped leaves. Mulch will help conserve soil moisture, keep vines and fruits clean. Slugs and snails find if difficult to move across straw or pine straw mulch.
- Grow cucumbers with beans, corn, peas, pumpkins, and squash. Do not grow cucumbers with potatoes and herbs.
Flowering and Fruit Formation
- Cucumbers have separate male and female flowers. The first flowers to appear are male flowers which will not produce fruit.
- Female flowers appear a week or so after male flowers. A female flower will have a cucumber-shaped swelling at the stem end of the flower; this is the unpollinated fruit.
- Female flowers are pollinated when bees or other insects carry pollen from the male flower to the female flower. Some male flowers may die and drop before female flowers appear. Be patient or sow seeds every couple of weeks so that there are male and female flowers in the garden at the same time.
- To attract bees to flowers, spritz plants with dilute sugar water.
- If plants are in a greenhouse or hoop house where pollinating insects cannot come or if pollination is slow or does not occur, use a soft-bristled brush to hand pollinate flowers; dust the inside of a male flower then carefully dust the inside of a female flower. A female flower will have an immature fruit on its stem, a male won't.
- Gynoecious, hybrid cucumbers require pollinator plants; monoecious plants with female flowers.
- Cucumber fruits hanging from a trellis or vertical support will grow straight under the force of gravity.
- Cucumbers growing on the ground should be set on a tile or piece of wood so that the fruit does not have direct contact with the soil; this will allow cucumbers to mature with less exposure to disease and insects.
- Cool weather, rain, and insecticides can delay or harm pollination.
- Cucumbers can be attacked by aphids, cucumber beetles, squash bugs, and slugs.
- Control aphids by hosing them off with a blast of water or pinching out infested vegetation.
- Cucumber beetles chew holes in leaves and can spread cucumber bacterial wilt when feeding on plant tissue. Hand-pick them off the vines and destroy them.
- Squash bugs suck plant sap causing leaves to wilt. Squash bugs will also attack seedlings. Dust plants with diatomaceous earth around the base of plants.
- Slugs can scrape ragged holes in leaves. Spread diatomaceous earth around the base of plants.
- Cucumbers plants are susceptible to scab, mosaic, and mildew.
- Keep the garden clean of debris and weeds that can harbor pests and disease.
- Remove diseased plants immediately; put them in a paper bag and throw them in the trash to avoid the spread of disease.
- Plant disease resistant varieties. Look for the following coding to indicate disease resistance: leaf spot (LS), anthracnose (A), bacterial wilt (BW), mosaic (M), scab (S), and downy mildew (DM).
- Bacterial wilt is spread by cucumber beetles; plants suddenly wilt and die just as they begin to produce. Control beetles as soon as they appear.
- Powdery mildew and downy mildew, fungal diseases, will cause cucumber leaves to turn grayish white late in the season. Slow the spread of fungal diseases by spraying plants with horticultural oil or neem oil.
- To help prevent fungal diseases, plant resistant varieties, and space plants further apart to increase air circulation.
- Cucumbers will be ready for harvest 55 to 65 days from sowing.
- Harvest cucumbers as soon as they reach mature size; cucumbers left on the vine past maturity will suppress the production of new flowers and fruit.
- Check and harvest cucumbers daily to stay ahead of the harvest.
- Slicing cucumbers are best picked when they are 6 to 8 inches long.
- Clips cucumbers off of plants with a garden clipper, scissors, or knife. Pulling cucumbers off plants can damage plants.
- A fruit that turns yellow at the blossom end opposite the stem is overripe and will be seedy.
- Pickling cucumbers–sweet or dill–are best picked when 1 to 6 inches long. Pick pickling cucumbers every two days.
- Regular dills are best picked when 3 to 4 inches long.
- Burpless cucumbers should be picked at about 10 inches long.
- Hothouse-grown English or Armenian cucumbers are best picked when 12 to 15 inches long.
- Cucumbers left on the vine too long will have tough skins and will lose flavor.
Storing and Preserving Cucumbers
- Pickling and slicing cucumbers will keep in the refrigerator for 7 to 10 days.
- Hothouse cucumbers will keep in the refrigerator for 1 to 2 days. Be sure the temperature is not too low or cucumbers will freeze and turn soft.
- Wrap refrigerated cucumbers in plastic or store them in a zipper bag to keep them crisp.
- Pickled cucumbers will keep for up to 1 year.
Monoecios and Gynoecious Cucumbers: The Difference
- Most cucumbers are monoecious, meaning plants produce both female and male flowers. Female flowers are commonly pollinated by insects after visiting male flowers.
- Hybrid cucumber varieties are gynoecious. Gynoecious cucumbers produce only female flowers. These plants must be set near a monoecious plant for pollination or must be pollinated by hand. Gynoecious cultivars include 'Conquest,' 'Early Pride,' and 'Bush Baby.'
Types of Cucumbers
There are many types and varieties of cucumbers. Here are the differences:
- Bush cucumbers can grow 24 to 36 inches tall and wide forming a compact plant. Bush cucumbers are well-suited for container growing or small gardens. Plant bush varieties every two weeks for a continuous harvest.
- Vine cucumbers can grow to 6 feet high or more and 2 to 3 feet wide. Vining cultivars require more space but produce more fruit. Grow vining cucumbers on a fence, trellis, or tripods when possible to keep fruit off the ground.
- Pickling cucumbers have a thin, pale green skin, bear fruit early, and concentrate fruiting in a 10-day period. Pickle cucumbers a few hours after harvesting for crisp pickles.
- Slicing cucumbers, for fresh eating, commonly are green-skinned and set fruit for 4 to 6 weeks. Slicing cucumbers include "burpless' cultivars which are mild flavored and easy to digest.
- European, English, or greenhouse cucumbers are seedless cultivars developed for greenhouse growing.
- Lemon cucumbers are yellow oval-to-round heirloom cucumbers. Lemon cucumbers are ideal for a single serving. Harvest lemon cucumbers just as they turn yellow; do not wait too long or they will be seedy.
- Asian cucumbers are thin, heavily ribbed cultivars; the fruit grows from 12- to 24-inches long.
- Gherkin is a term used for any pickling cucumber; however, a true gherkin is not a cucumber but the fruit of a different species, Cucumis anguria.
- Cornichons is the generic French term for any small cucumber.
- Grow 2 to 3 cucumber plants per household member for fresh eating.
- Grow 3 to 4 plants per quart for pickling.
Cucumber Varieties to Grow
Cucumbers are divided into the slicing cucumbers for fresh eating and pickling cucumbers. There are dozens of varieties to choose from. In the list below "gyn" denotes gynoecious which produce only female flowers and must be grown near a monoecios plant; others are monoecios, they produce both male and female flowers.
- Slicing:Ashley (66 days); Comet II (gyn-60 days); Dasher II (55 days); General Lee (gyn-55 days); Jazzer (48 days); Marketmore (76 days); Poinsett (65 days); Revenue (gyn-48 days); Slice King (49 days); Spacemaster (60 days); Speedway (gyn-56 days); Supersett (53 days); Sweet Slice (62 days); Tasty Green (55 days); Ultra-Slice Early (56 days).
- Pickling:Baby Bush (51 days); Calypso (gyn-56 days); Conquest (gyn-50 days); Cross Country (51 days); Edmondson (70 days); Green Spear (gyn-55 days); Pik Rite (gyn-63 days); Salty (53 days); Spear It (gyn-52 days); Sumter (56 days).
- Burpless: Comet II (gyn-60 days); Green Knight (60 days); Jazzer (48 days); Perfection (60 days); Sweet Slice (62 days); Tasty Green (55 days).
- Greenhouse:Aidas (gyn-65 days); Carmen (gyn-65 days); English Telegraph (65 days).
- Container varieties: Patio Pic (50 days); Potluck (50 days); Spacemaster (60 days); Bush Whopper.
- Others: Lemon (64 days); Long White (65 days); White Wonder (60 days).
- Cucumber is a weak-stemmed tender annual that grows. Some varieties grow like a bush, others are vining.
- Leaves are somewhat heart-shaped with rough margins; leaves and stems are covered with prickly short hairs.
- Flowers are yellow.
- Fruits are commonly pale or dark green but some varieties are yellow or white; fruit ranges in size from 3 inches (7 cm) to more than 24 inches (61 cm) long.
- Botanical name: Cucumis sativus
- Origin: Asia