Give cucumber the room to grow.

Cucumber is a tender, warm-season vegetable that produces well when given proper care and protection. The vines of standard varieties grow rapidly and require substantial space. Vertical training methods and new dwarf varieties now allow cucumbers to be grown for slicing, salads and pickling, even in small garden plots.

Growing Cucumber

When to Plant

Cucumbers are usually started by planting seeds directly in the garden. Plant after the danger of frost has passed, and the soil has warmed in the spring. Warm soil is necessary for germination of seeds and proper growth of plants. With ample soil moisture, cucumbers thrive in warm summer weather. A second planting for fall harvest may be made in mid- to late summer.

Cucumbers may be transplanted for extra-early yields.

• Sow two or three seeds in peat pots, peat pellets or other containers 3 to 4 weeks before the frost-free date.
• Thin to one plant per container.
• Plant transplants 1 to 2 feet apart in rows 5 to 6 feet apart when they have two to four true leaves.
• Do not allow transplants to get too large in containers or they will not transplant well.
• Like other vine crops, cucumbers do not transplant successfully when pulled as bare-root plants.

Spacing & Depth

• Plant seeds 1/2 to 1 inch deep.
• Thin the seedlings to one plant every 12 inches in the row or to three plants every 36 inches in the hill system.
• If you use transplants, plant them carefully in warm soil 12 inches apart in the row.

Care

Cucumber plants have shallow roots and require ample soil moisture at all stages of growth. When fruit begins setting and maturing, adequate moisture becomes especially critical. For best yields, incorporate compost or well-rotted manure before planting. Cucumbers respond to mulching with soil-warming plastic in early spring or organic materials in summer. Use of black plastic mulch warms the soil in the early season and can give significantly earlier yields, especially if combined with floating row covers.

Side-dress with nitrogen fertilizer when the plants begin to vine. Cucumber beetles should be controlled from the time that the young seedlings emerge from the soil.

In small gardens, the vines may be trained on a trellis or fence. When the long, burpless varieties are supported, the cucumbers hang free and develop straight fruits. Winds whipping the plants can make vertical training impractical. Wire cages also can be used for supporting the plants. Do not handle, harvest or work with the plants when they are wet.

Common problems for cucumber, muskmelon, pumpkin, squash (summer and winter), watermelon

• Cucumber beetles: 1/4 inch long. Black and yellow spotted or striped beetles. Feed on foliage, flowers, stems or fruit. Fly from one plant to another.

Symptoms of damage:

• Holes in foliage
• Chewed flowers
• Scarred stems and fruit surfaces

Spotted and striped cucumber beetles attack seedlings as they emerge from the soil. The beetle may appear in large numbers and can quickly stunt or kill the small plants. Beetles may carry bacterial wilt disease that causes plants to wilt and die.

• Aphids: Watch for buildup of colonies of aphids on the undersides of the leaves.
   
• Bacterial Wilt: Plants are infected with the bacterial wilt disease by the attack of cucumber beetles. The disease organism overwinters inside the beetles' bodies. The beetles hibernate among the trash and weeds around the garden, emerging in time to feed on tender cucumber seedlings. Plants usually are infected with the disease-causing bacteria long before they show any symptoms. When the vines wilt and collapse (usually about the same time that the first cucumbers are half grown), it is too late to prevent the disease.
   

Harvesting Cucumbers

Pick cucumbers at any stage of development before the seeds become hard. Cucumbers usually are eaten when immature. The best size depends upon the use and variety. They may be picked when they are no more than 2 inches long for pickles, 4 to 6 inches long for dills and 6 to 8 inches long for slicing varieties. A cucumber is of highest quality when it is uniformly green, firm and crisp. The large, burpless cucumbers should be 1 to 1 1/2 inches in diameter and up to 10 inches long. Some varieties can grow considerably larger. Do not allow cucumbers to turn yellow. Remove from the vine any missed fruits nearing ripeness so that the young fruits continue to develop. The cucumber fruit grows rapidly to harvest size and should be picked at least every other day.

Selection and Storage 

There are two types of cucumbers common to the home gardener: pickling cucumbers and slicing cucumbers. The phrase "cool as a cucumber" is an apt one. Growing in a field on a hot summer day, the interior flesh is 20 degrees cooler than the outside air temperature.

• Harvest cucumbers early in the morning (before they have been heated by the afternoon sun) and refrigerate immediately.
• Store for up to 3 days in the refrigerator in loose or perforated plastic bags.
• Supermarket cucumbers are covered with an edible wax to protect them from moisture loss. The wax gives them an unnatural sheen.
• Fresh cucumbers are dull green in color.

Pickling cucumbers: Pickling cucumbers should be picked every day, since they can quickly grow too large for use. Do not leave over-mature, yellow cucumbers on the vine. If a single cucumber is left on the vine, the vine will stop producing altogether.

Slicing cucumbers: Slicing cucumbers should be harvested as needed, but there is no practical use for baseball bat size cucumbers. They are tough and the seeds are woody. Harvest when they are 8 inches long or smaller. As with pickling cucumbers, remove the over mature ones as soon as you see them or they will halt the growth of new cucumbers.

Questions and Answers About Growing Cucumber

Q. Some of my small cucumbers are badly misshapen. Will they develop into normal cucumbers?

A. No. They should be removed from the vines. Misshapen cucumbers may result from poor pollination or low fertility. Side-dressing with a complete fertilizer may help later cucumbers to develop normally.

Q. Why do some of my plants suddenly wilt and die? Dead or dying plants are scattered all over my cucumber patch. One plant in a hill may be healthy, while another dies.

A. These are typical symptoms of the bacterial wilt disease. This disease is spread by cucumber beetles early in the season. The beetles must be controlled immediately when the plants are small.

Q. Is there really a "burpless" cucumber?

A. Yes. Burpless cucumbers are no longer considered novelties and are offered in most garden catalogs. They are mild, sweet and crisp when fresh. The skin is tender and free of bitterness, although many people still peel it off. Most varieties are long (10 to 12 inches) and curved, unless grown on a trellis. These varieties are better eaten fresh, using conventional varieties for most pickling uses.

Q. What cucumber variety should I buy for gherkins?

A. Buy the West Indian gherkin. It is a close relative of the garden cucumber used for pickling. The fruits are generally oval, 1 to 3 inches long and more spiny than cucumbers. They are also called "burr cucumbers" but are usually listed in catalogs as West Indian gherkin. They are grown in the same way as cucumbers. Small-fruited, prickly varieties of cucumber are sometimes sold as "gherkins." If small, tender cucumbers are what you want to pickle and call "gherkins," then these misnamed cucumber varieties serve the purpose well.

Q. Why do my cucumbers fail to set fruit and yield properly?

A. The first yellow flowers appearing on the plants are male flowers that provide pollen. These flowers normally drop off after blooming. The small cucumber is evident at the base of the female flower (even before it opens) and should develop into an edible fruit if properly pollinated. Anything that interferes with pollination of the female flowers reduces fruit set and yield, including cold temperatures and rainy weather that hamper bee activity or improper use of insecticides that kill bees.

Q. What are gynoecious hybrids?

A. Gynoecious ("female-flowering") hybrids are special hybrids of slicing and pickling cucumbers that are advertised in many garden catalogs. Because they have all female flowers, they may be earlier and higher yielding than other varieties. Usually, the seed company mixes in a small proportion of seed of a standard cucumber as a pollinator.

Q. How far away from melons should I plant my cucumbers? I am concerned about cross pollination.

A. Contrary to popular opinion, cucumbers do not cross-pollinate with muskmelons or watermelons and cause them to become bitter, tasteless or off-flavor. Because cucumbers and melons require considerable space in the garden, however, plant the rows far enough apart for proper vine growth without overlapping.

Q. What causes my cucumber plants to be stunted? The leaves are a mottled yellow, and the fruits are blotchy and taste bitter.

A. This condition is caused by the cucumber mosaic virus. Grow mosaic-resistant varieties.

Q. What causes the white mold growth on the upper surfaces of my cucumber leaves?

A. This condition is caused by powdery mildew, a fungal disease that is most severe during late summer and fall plantings. Grow resistant varieties.