Several different types of cucumbers are available to home gardeners. Slicing cucumbers are generally long and cylindrical with dark green skins. Pickling cucumbers are short and blocky. "Burpless" varieties produce mild flavored fruit. For individuals with small gardens, compact or bush varieties are available.
Cucumbers perform best in fertile, well-drained soils in full sun. If a soil test has not been conducted, apply and incorporate 1 to 2 pounds of an all-purpose garden fertilizer, such as 10-10-10, per 100 square feet prior to planting.
Cucumbers are a warm-season crop. Plant cucumbers after the danger of frost is past and soil temperatures have warmed to 60 to 70F. In central Iowa, cucumbers may be planted in mid-May. Gardeners in southern Iowa can plant 1 week earlier. Plant 1 week later in northern portions of the state. The last practical date to sow cucumbers is July 20.
Cucumbers are normally planted in "hills." Plant 4 to 5 seeds per hill at a depth of 1 inch. Later, remove all but 2 or 3 plants per hill when seedlings have 1 or 2 true leaves.
For an earlier crop, cucumbers can be started indoors. Start seeds indoors 2 to 3 weeks before the anticipated outdoor planting date. Peat pots, Jiffy 7's, and other plantable containers work best as both plant and container are transplanted into the garden, resulting in little damage to the plant s root system. Sow 3 to 4 seeds per container. Later, remove all but 2 seedlings. Transplant outdoors when plants have 1 or 2 true leaves. Prior to planting, harden the plants outdoors for a few days in a protected location to lessen transplant stress.
Hills of cucumbers should be spaced 3 to 5 feet apart within the row. Rows should be 4 to 5 feet apart. For bush varieties, a three-foot spacing between hills and rows should be adequate.
Cucumbers can also be grown in rows. Sow seeds 6 inches apart. After germination, thin the seedlings so remaining plants are spaced 15 to 18 inches apart.
Flowering and Fruiting
Cucumbers and other vine crops are monoecious. Monoecious plants have separate male and female flowers on the same plant. Male and female flowers are similar in appearance. However, the female flowers have small, immature fruits at their base. Pollen is transferred from the male to the female flowers by bees. When properly pollinated and fertilized, the female flowers develop into fruit. The first flowers to appear on cucumbers and other vine crops are male. Female flowers appear shortly thereafter.
Gynoecious varieties are special hybrids which produce predominantly female flowers. Seeds of a standard monoecious variety are commonly included in the seed packet to ensure adequate pollination. (The seeds of the monoecious variety may be dyed or placed in a separate packet.) Gynoecious varieties often outproduce standard varieties when a pollenizer (monoecious variety) is present.
There are also parthenocarpic cucumber varieties. These varieties develop fruit without pollination. As a result, the non-fertilized fruit do not contain seeds. Parthenocarpic varieties must be isolated from standard varieties to prevent cross-pollination and seed development.
Cucumbers will not cross-pollinate with squashes, pumpkins, muskmelons, or watermelons. Cucumber varieties may cross with one another. However, the quality of this year s crop is not affected. (An exception is the cross-pollination of parthenocarpic varieties with standard varieties.)
Suggested cucumber varieties
- Thunder - very early.
- Fanfare - semi-bush, monoecious, 1994 All-America Selection.
- Marketmore 76 - uniform, dark green fruit.
- County Fair - nearly seedless if isolated from other cucumbers.
- Calypso - gynoecious, early to mid-season.
- Fancipak M - gynoecious, early to mid-season.
- Diva - gynoecious, parthenocarpic, 2002 All-America Selection.
- Sweet Slice - monoecious, slicing.
- Tasty Green - monoecious, slicing.
- Salad Bush - 1988 All-America Selection, slicing.
- Spacemaster - slicing.
- Bush Pickle - pickling.
- Lemon - similar in size and appearance to a lemon, light yellow skin, white flesh.
- White Wonder - cylindrical fruits with ivory-white skin.
Control weeds with frequent, shallow cultivation and hand pulling until the vines cover the ground. Water plants once a week during dry weather. Prevent cucumber beetles from damaging young plants by covering them with floating row covers or other protective materials or by using insecticides. (Remove the protective coverings when flowering begins.) Cucumber plantings made after mid-June are less likely to be damaged by cucumber beetles because of the smaller population of adult beetles.
Bitterness in cucumbers develops when the plant is stressed by hot, dry weather. The bitterness is produced by the compound cucurbitacin. Cucurbitacin tends to be concentrated in the stem end of the cucumber and just under the skin. To eliminate most of the bitterness, cut off the stem end of the fruit and peel the remaining portion of the cucumber. To avoid the problem, plant bitter-free cucumber varieties, such Sweet Slice.
Poorly-shaped fruit are usually the result of poor pollination. Poor pollination may be due to cool, wet weather and improperly applied insecticides that limit bee activity. When insecticides are necessary, select an insecticide with a low toxicity to bees and apply it early in the morning or late in the evening to reduce the risk to bees.
Harvest and Storage
Harvest cucumbers every 2 to 3 days and promptly pick the fruits when they reach the desired size. Pickling varieties should be harvested when the fruits are 2 to 4 inches long. Slicing cucumbers should be 6 to 8 inches long and 1 1/2 to 2 inches in diameter, but still dark green and firm. Over-mature cucumbers left on the vine inhibit additional fruit set.
Cucumbers can be stored for 10 to 14 days at 50 to 55 F and 90 to 95% relative humidity.
This article originally appeared in the April 5, 2002 issue, pp. 34-35.