Cucumber

History

Cucumbers are members of the Cucurbitaceae family, also known as the cucurbits or gourd family (see Figure 1). The group includes crops such as the winter and summer squash, watermelon, cantaloupe, pumpkins, and gourd.

It is believed that cucumbers originated in India over 3,000 years ago, and then spread to China, Greece, Italy, and North Africa (see Figure 2). By the 9^th century, cucumbers were grown in France, likely transported by the Romans. They were not documented in England until the 14^th century. Cucumber was then transported to the Americas during colonization led by Columbus around the mid-1500s and was grown in early Virginia and Massachusetts settlements. By 1650, cucumbers were grown in South America.

Cucumbers are annuals (with a life cycle of one year) that require a long, warm growing season. Tolerant of hot weather, many cucumber varieties are highly suitable to the Louisiana climate.

Varieties

Cucumbers can be divided into two main types: (1) slicer or fresh market and (2) pickling (see Figure 3). Slicer cucumbers are generally long and dark green with a smooth, thick skin. Pickling cucumbers are lighter green, short and blocky, with a warty/bumpy, tender skin. They are an ideal size and shape for pickling but can also be consumed fresh. Many slicer and pickling types are particularly well suited for the hot and humid Louisiana climate, such as Ashley, General Lee, and Tasty Green.

Other specialty cucumber types include English (also known as greenhouse, or Long Dutch), which produce very long, slender, and seedless fruit; and miniature, which produce smaller fruit (see Figure 3). Cucumber plants have a vining growth habit that is either indeterminate (continuous growth until plant death), determinate (a set, “determined” growth), or compact (shorter growth).

Cucumbers have either open-pollinated (including heirloom) or hybrid varieties. Some cucumber varieties are heirlooms, like Suyo Long and Boston Pickling, meaning the seeds have been saved for at least 50 years, can be saved each season and replanted, and are open-pollinated. Most cucumber varieties (except English/greenhouse) are insect-pollinated, so if saving seed, different varieties must be separated by a distance of 800 feet-1/2 mile to avoid easy cross-pollination. Generally, it is not recommended to save seed for future planting with hybrid varieties, as they are usually not expressed properly in the next generation.

Cucumber plants are mostly monoecious, which produce both male and female flowers on the same plant, but gynoecious types, which only produce female flowers, also exist. Both male and female flowers are open for a single day. Male flowers open about 10 days before female flowers and outnumber female flowers. Gynoecious types are often preferred since only female flowers produce fruit, generally mature earlier with a higher yield, and have a more concentrated fruit set. To produce pollen in the garden, 1 pol­linizer plant must be planted for every 10 gynoecious plants; this seed is included in the seed packet along with the gynoecious variety.

Some cucumber varieties are also parthenocarpic, which bear fruits without pollination, resulting in seedless cucumbers. Seedless cucumbers are also referred to as “burpless,” meaning they bear fruits with thin, non-bitter skin. Parthenocarpic cucumbers have been traditionally grown in greenhouse and high tunnel conditions (lower light; higher humidity and temperature) to prevent bees from cross-pollinating flowers and causing seed development. They have better disease resistance than other types. Nearly all English cucumber varieties are seedless and thin skinned.

It is recommended to select disease-resistant varieties whenever possible. See the recommended cucumber varieties for Louisiana in Table 1.

Table 1. Recommended Cucumber Varieties for Louisiana

When and How to Plant

Cucumber should be direct seeded outside during the recommended planting dates (see Table 2). As it is a warm season crop, plant cucumber seeds outside when the soil temperature has warmed to 60-95 degrees F (optimum of 85-95 degrees F; minimum of 60 degrees F). If planting early when soil temperatures reach 60 degrees F, be sure there is no danger of frost and consider using row cover and plastic mulch for protection and to increase soil temperature. The use of a soil temperature map can help guide planting decisions.

Refer to the Cucumber Planting Guide (Table 2) for the recommended spacing when direct seeding outside. Sow about 3 seeds 1/2-3/4 inch deep, cover with soil, and water in. Seeds should emerge in about 5-10 days. Then, thin to 1 plant at the recommended spacing distance. After germination, cucumber plants prefer warm days (80-90 degrees F) and warm nights (60-70 degrees F) with low humidity. Temperatures above 95 degrees F or below 60 degrees F may stunt plants and reduce yield.

Cucumbers can also be started inside and transplanted outside. Due to rapid growth it is recommended to start seeds only 3-4 weeks before planting outside; otherwise seedlings may become stunted, too large for successful transplanting, and the transplants may have already started flowering.

Table 2. CUCUMBER PLANTING GUIDE

Where to Plant

Cucumbers are a warm season crop that prefers well-drained, aerated soil, and full sun (at least 6 hours/day). Cucumber plants prefer a soil pH between 5.5 and 7.0. It is recommended to plant in box beds or in traditional raised garden rows that are 4-6 inches tall to ensure good drainage and prevent disease. In all types of gardens, it is recommended to add a 2- to 3-inch layer of compost, peat moss, rotted hay, or other organic matter and mix into the soil to optimize plant health. This is especially important for cucumbers as they thrive in soil high in organic matter. If cucumber plant leaves turn yellow or bronze, the soil may be deficient in nitrogen or potassium, respectively.

Black plastic mulch — or a plastic fabric/film — is recommended to increase soil temperature and improve yield, fruit size and quality, while controlling weeds and conserving moisture. Mulching will also help to deter common cucumber insect pests like cucumber beetles. Organic mulches like straw or hay can also be used.

Floating fabric row covers are also recommended for this crop, to improve growth and deter pests during the seedling stage. Row covers should be removed when plants enter the flowering stage of growth to optimize pollination.

Each season, rotate plant families — avoid planting crops from the same plant family in the same area of the garden — to reduce disease and insect pests. A longer crop rotation of 3-4 years is recommended for Cucurbitaceae crops to reduce insect pest pressure and risk of disease.

Plant Care

Watering

Deep, uniform watering is important for cucumber plants as their root system can be 3-4 feet deep. Avoid wetting the plant foliage. When cucumber plants experience drought, the fruit may become bitter and underdeveloped. Adequate watering is essential during germination, vining, and fruit development. In general, vegetable crops require 1 inch of rain or supplemental irrigation per week.

Fertilization

Cucumbers require sufficient but not excessive nitrogen. If over-fertilized or grown following beans or other legumes, plants may produce excessive vines and little fruit. As a long season crop, it is important to continue to sidedress cucumbers to keep plants productive.

Organic fertilizers such as compost, fish emulsion, composted poultry litter or manure, worm castings, and blood or bone meal originate from living organisms. They are far more environmentally sustainable and safe than traditional synthetic fertilizers. They naturally release nutrients more slowly and over a longer period of time. When applying organic fertilizer, it is important to use in unison with compost, cover crops, and crop rotation, which all work together to build soil health. Learn how to convert inorganic fertilizer recommendations to organic fertilizers here.

Alternatively, a synthetic fertilizer may be used at the rate of about 1 pound (2 cups) of 13-13-13 for every 25 feet of row or 75 square feet. Broadcast or sprinkle evenly over the soil and then mix in about 3-6 inches deep using a rake. Supplemental sidedressing, or reapplication of synthetic fertilizer, is recommended when plants start vining. Sidedressing is the addition of a small amount of fertilizer to the soil around already established plants when the plant begins to fruit or vine, primarily to provide nitrogen. When using synthetic fertilizer, sprinkle 2 tablespoons around each plant, keeping it about 6 inches away from the plant stem; water into the soil. Additional sidedressing may be applied every 3-4 weeks. Fish emulsion can provide a quick-release form of nitrogen for sidedressing with an organic fertilizer.

Support

For all cucumber types it is recommended to use stakes, mesh trellises, or a wire fence at least 6-8 feet tall for support. This will improve fruit quality, optimize yield, keep fruit clean, and increase ease of harvest. It is recommended to use a nylon netting mesh trellis that is attached to T-posts for easiest setup, portability, and durability. This support method allows more air circulation than stakes provide and is more portable than a wire fence. Here is a helpful video explaining trellising using nylon netting and plastic C-clips to train a vertical growth habit. As plants grow, they will self-attach with tendrils (see Figure 5).

Bitterness

Crops in the Cucurbitaceae family produce cucurbitacin, a chemical that causes bitter-tasting fruits. The likelihood of bitter fruit increases with close, intensive planting of crops from this family, and can also be triggered by high and/or fluctuating temperatures, low and/or irregular irrigation, and low soil fertility and/or pH.

Weeds

Plastic or organic mulch will control most of the weeds; hand-pull weeds close to the plant, especially those growing in the planting holes.

Insect Pests and Diseases

Aphids are a common insect pest for cucumber plants and can transmit harmful viruses like cucumber, watermelon, and zucchini yellow mosaic viruses and papaya ringspot virus. Other common cucumber insect pests include cucumber beetles, spider mites, and whiteflies. Regular monitoring can help identify symptoms of these insect pests and allows for early treatment and management. Cucumbers are also susceptible to viruses (e.g., cucumber, watermelon, and zucchini yellow mosaic viruses and papaya ringspot virus) and fungal diseases (e.g., anthracnose, downy, and powdery mildew). Some varieties are resistant to specific diseases and these should be selected and planted. Generally recommended tools for prevention are using reflective mulches, avoiding overhead irrigation, improving air circulation by trellising and adequate plant spacing, and crop rotation (at least 3-4 years). See Table 3 to aid in diagnosis and management of some common cucumber insect pests and diseases.

Table 3. Organic and Natural Management for Common Cucumber Insect Pests and Diseases

Harvest and Storage

Cucumbers are harvested when fruit reaches harvest size, or every 2-3 days for 3-4 weeks. It is recommended to use shears to clip the stems when harvesting cucumbers (avoid twisting/breaking the stems). Consistent harvesting and removal of overmatured fruit (indicated by yellowing skin) is essential for optimal production length and yield. After harvest, the crop needs to be cooled down to remove field heat and placed in a refrigerator or cooler where there is high humidity. Removing field heat will help prevent moisture loss and wilting and will preserve quality and shelf life. Cucumbers should be stored between 50-55 degrees F (95% humidity) for 10-14 days.

Preserve cucumbers by pickling and canning.

Cucumbers are Nutritious and Good for You

Rich in Vitamin A

Important for eye health, a strong immune system, and cell growth

Good source of Vitamin K

Helps your body heal and is important for bone health

High in Potassium

Essential for body function, especially the heart, kidney, nerves, bones, and muscles

Contains Vitamin C

Important for bones, skin, blood vessels

Great source of dietary fiber

Important for bowel health, lowering cholesterol, controlling blood sugar, and maintaining a healthy weight

Recipes

Louisiana Harvest of the Month: Cucumber & Tomato Salad

Common methods of preparing cucumbers

Video on how to peel, cut, and de-seed cucumbers

Tip sheets for Quick Pickles, Pickling, and Fermenting Cucumbers

Taste-testing ideas: cucumber yogurt dip (tzatziki), tuna cucumber boats, quick pickles, cucumber water, cucumber salad

Other websites with many cucumber recipes:

USDA MyPlate Kitchen

Food Hero

SNAP-Ed San Francisco

Produce for Better Health Foundation

Sources

• Southeastern Vegetable Extension Workers, 2020 Southeastern U.S. Vegetable Crop Handbook
• LSU AgCenter, Louisiana Vegetable Planting Guide
• LSU AgCenter, Louisiana Commercial Vegetable Production Recommendations
• LSU AgCenter, Vegetable Gardening Tips: Cucumbers
• UF Extension, Planting Guide
• UF Extension, Vegetable Production Handbook of Florida
• Texas A&M AgriLife Extension, Vegetable Varieties for Central Texas
• Texas A&M AgriLife Extension, Easy Gardening: Cucumbers
• Texas A&M AgriLife Extension, Commercial Crop Guides: Cucumber (pickling)
• Texas A&M AgriLife Extension, Commercial Crop Guides: Cucumber (slicing)
• Texas A&M AgriLife Extension, Aggie Horticulture: Pickles and Salads Owe a Debt to India
• Maynard, Donald N & Hochmuth, George J (2007). Knott’s Handbook for Vegetable Growers (5th edition). John Wiley & Sons, Inc.
• Decoteau, Dennis R (2000). Vegetable Crops. Prentice-Hall, Inc.
• Swiader, John M & Ware, George W (2002). Producing Vegetable Crops (5th edition). Interstate Publishers, Inc.
• UMass Extension Vegetable Program: Disease, Insect, and Mites Fact Sheets
• Alabama A&M & Auburn Universities Extension, Crop Production
• Seebold, K (2010). UK Cooperative Extension Service, Plant Pathology Fact Sheet: Fruit Rots of Cucurbits.
• Purdue Extension FoodLink: Cucumbers
• Sukprakarn, S, Juntakool, S, Huang, R, and Kalb, T (2005). Saving your own vegetable seeds—a guide for farmers. AVRDC publication number 05-647. AVRDC—The World Vegetable Center, Shanhua, Taiwan. 25 pp.
• Seed Savers Exchange, Seed Saving: A Guide to Isolation Distances
• University of Georgia Extension, How to Convert an Inorganic Fertilizer Recommendation to an Organic One, Circular 853