Cucumber (Cucumis sativas)-Hort Answers - University of Illinois Extension
University of Illinois Extension

University of Illinois Extension

Hort Answers


Cucumis sativas


Cucumbers require fertile, well-drained soils, and full sun. Test the soil, and apply, and incorporate recommended amounts of fertilizer. If a soil test has not been done, incorporate 1-2 pounds of garden fertilizers such as 10-10-10 per 100 square feet before planting.

Cucumbers for transplanting can be started indoors 2-3 weeks before planting outdoors. Peat pots, jiffy pellets, or flats with cells can be used. When using flats or peat pots, fill them with soilless potting mix. Sow more seeds per container or cell then thin to the desired number after germination. Harden the seedlings outdoors in a protected location to reduce plant stress before transplanting.

Cucumbers and other vine crops are monoecious plants which have separate male and female flowers on the same plant. The male flowers appear first and female flowers shortly later. The female flowers have small immature fruit at the base of the flower and male flower do not have any. Pollen is transferred from male to female flower by bees or other insects. When pollinated properly, female flower develops into fruit. There are different types of cucumber hybrids such as gynoecious varieties that produce predominantly female flowers, and seeds of monoecious varieties are mixed with it for pollination. They are very productive when pollenizer is present. There are also cucumber hybrids that produce fruits without pollination called parthenocarpic varieties resulting into fruits that contain no seeds. Such varieties need to be isolated from standard varieties to prevent cross-pollination and development of fruits with seeds inside. Cucumbers cucumber varieties can cross pollinate with one another but not with squash, pumpkins, muskmelons, or watermelons.

Cucumbers can be grown on bare ground or in black plastic mulch. When planted on bare ground, control weeds with frequent, shallow cultivation, and hand pulling until the vines cover the ground. When grown plastic mulch, weeds need to be controlled between plastic mulch strips. Irrigate once a week and the amount of water applied depends on amount of rainfall in a week. Control cucumber beetles as soon as they are observed on the plants by using floating row cover, or by using insecticides. When floating row cover is used, remove it when flowering begin. 

Slicing – Thunder – Very early; Dasher II – very productive, midseason; Fanfare – Semi-bush, monoecious; Marketmore 76 – uniform, dark green fruit

Pickling – County Fair – seedless if isolated from other cucumbers; Calypso – gynoecious, early maturing; Farncipak M – gynoecious, early season.

Burpless – Diva – gynoecious, parthenocarpic; Sweet Slice – monoecious slicing; Tasty Green – Monoecious, slicing

Bush – Salad Bush – slicing; Spacemaster – slicing; Bush Pickle – pickling.

Heirloom – Lemon – light yellow skin, white flesh, round and similar in size to lemon; White Wonder – cylindrical fruits with ivory-white skin.

Planting Time
Cucumbers are warm season vegetables that are planted after the danger of frost is past. They germinate when soil temperatures have warmed to 60-70 degrees F. Some early maturing cucumber varieties can be planted as late as towards the end of second week of July.


Harvest Time
Harvested in summer to early fall depending on planting time, and variety. Harvest cucumbers every 2-3 days when the fruits have reached desired size. Harvest pickling types when fruits are 2-4 inches long, and slicing types when fruits are dark green, firm, 6-8 inches long with a diameter of 1½ - 2 inches. Over mature cucumbers left on the vine inhibit new fruit set. Cucumbers can be stored for about two weeks at 50-55 degrees F and 90-95% relative humidity.


Cucumbers can be planted in hills or in rows. In hills, plant 4-5 seeds per hill at a depth of 1 inch. After germination when the seedlings have 2-3 true leaves, thin 2-3 plant per hill. Hills need to be spaced 3-5 ft apart within the row, and the rows should be 4-5 ft apart. For bush varieties, 3-ft apart within row spacing is adequate. Cucumbers grown in rows are spaced 6 inches apart within row at planting time, and thinned to after germination so that they are spaced about 12 inches apart. Cucumbers can be direct seeded or transplanted.


Soil Conditions
Moist, Well-Drained
Exposure/Light Requirements
Full Sun
Pests and Problems

Bacterial Disease

Environmental Damage

Fungal Disease

Insect Damage

Additional pests and problems that may affect this plant:


  • Fusarium crown and fruit rot (Fusarium solani f.sp. cucurbitae)
  • Fusarium wilt (Fusarium oxysporum)
  • Plectosporium blight (Plectosporium tabacinum)
  • Scab (Cladosporium cucumerinum)
  • Root knot nematode (Meloidogyne spp.)
  • Viral diseases: cucumber mosaic, Papaya ringspot, Squash mosaic, Watermelon mosaic, and Zucchini yello mosaic
Additional Notes

Bitterness of fruit occurs when plant is stressed by hot, dry weather. Plant bitter free varieties such as Sweet Slice. Misshapen fruits occur due to poor pollination. Spray when bees are out of the field either late in the evening or early in the morning.


Related Resources
Home, Yard & Garden Pest Guide
U of IL - Distance Diagnosis through Digital Imaging
U of IL - Plant Clinic