Cucumber (Cucumis sativus) is one of those vegetables that you don’t need a lot of plants to get a lot of harvest. They are pretty easy to grow and with a little input and planning, you can have fresh cukes from early May right up till frost.

Nutritional Value Cucumbers are 95% water. They are understandably low calorie and low fat but still have descent amounts of fiber, vitamins, and minerals; most significantly vitamin K. (See Table 1 at end of article).

Botany Cucumbers are members of the Cucurbitaceae family commonly referred to as cucurbits. This family includes other vegetables like squash (summer and winter), pumpkins, zucchini, watermelon, cantaloupe, cushaw, cucuzzi, and mirliton. Cucumbers flowers are imperfect having separate male (staminate) and female (pistillate) flowers. They are, generally, dioecious (have both male and female flowers on the same plant). Breeders have developed varieties that are gynoecious having only female flowers as well as parthenocarpic varieties (do not require pollination for fruit production). Cucumbers have showy yellow flowers with 5 petals, 5 sepals, 5 stamens that are often fused, or 3 carpels. Female flowers are epigynous meaning they have an inferior ovary – it is situated below the attachment of the flower parts. The male and female flowers are 3/4”-1.5” diameter and are easily distinguished because the female flower ovary looks like a tiny cucumber fruit just below the petals.

A cucumber vine growing in the LaSalle Park.

The fruit is a pepo botanically which simply means a fleshy watery fruit with numerous seeds and a hard or leathery rind. The immature fruits are the edible stage and have a white to dark green skin depending on variety. Mature fruits are yellow to deep orange. While still edible, they are not as flavorful and have a tough skin. The white seeds range from 0.2-0.3” long, with a notched margin and are elliptical with pointed ends. The plants are generally sprawling climbers though smaller “bush” types have been developed. The alternately arranged triangular hairy leaves have 3-7 pointed lobes and toothed margins. The curling tendrils aid the plant in climbing and clinging.

Cucumber female flower (A) and male flower (B).

Cucumber Types: A – Slicer, B – Pickler, C – Thin Skinned, D – Cocktail

Cucumber varieties are generally placed into one of 4 types: slicers, picklers, thin-skinned, cocktail.

Slicers: These varieties produce high yields of large cucumbers with generally thicker skins. Varieties produce 7–9” long dark green fruit at harvest. However, white skinned varieties are also available. The skin is edible but often imparts a slight bitterness. These are usually waxed when sold in the grocery store. For these two reasons, they are typically peeled before eating.

Picklers: Fruit size varies depending on variety but are in the 2”–5” range. Pickling cucumbers varieties are developed for canning but are also delicious eaten fresh because they are crisp and juicy. Harvested fruit is usually lighter in color than slicers but ranges from white to dark green. Pickling varieties often have numerous, easily removed spines on the fruit.

Thin-Skinned: The group of cucumber varieties is of ten further categorized into 3 subtypes: European, Asian, Beit Alpha. Fruits of the European and Asian varieties are generally 10”-14” long. In the grocery store, these are usually individually shrink-wrapped because the thin skin offers less protection from dam age and dehydration during shipment and storage. The Beit Alpha varieties produce smaller fruit (3”-5”) with a very thin skin and are great for fresh snacking. Many of the thin-skinned varieties are commercially produced in greenhouses.

Cocktail: The fruit is usually harvested at 3–4” in length. Cocktail cucumber varieties are regarded as some of the best for their flavor and crunchy texture. Their small size, thin skins, and lack of spines make them favorable for fresh eating as snacks. These are usually grown in greenhouses and sold in bags or clamshells to prevent them from dehydration.

Site

Cucumbers grow best in a rich sandy loam soil but will do well in almost any well-drained soil. Without proper drainage, root diseases are sure to be a problem. Soil pH should be in the 5.8-6.8 range, but they can bear a satisfactory harvest at soil pH’s a little higher or a little lower. It’s easy to adjust your soil pH using sulfur (decrease pH) or lime (increase pH).

Cucumbers prefer full-sun locations that receive a minimum of 8 hours of full sunlight daily. Less than optimal sun conditions lead to more insect and disease problems and reduced productivity. Most varieties require a lot of garden space unless they are trellised. Cucumbers are also productive if grown in containers. The container should be a minimum of 5 gallons to provide sufficient water holding capacity. Water stressed plants wilt easily and it increases fruit bitterness. Bush varieties are developed for small gardens and container growing.

Planting

Cucumbers can be direct seeded in the garden or started indoors as transplants. Cucumber seed will not germinate if the soil temperature is below 50°F and optimal temperature for germination is 80-90˚F but seeds will germinate reliably in the 65-90°F range. Remember, we’re talking soil temperature not air temperature. Seeds should be planted ¼” to ½” deep and covered. Plants will emerge in 3-10 days depending on temperature. Grow transplants 3-4 weeks before transplanting to the garden. Depending on variety, it is 50-65 days to first harvest. A soil test should be obtained prior to planting. Follow recommendations from the report for optimal soil nutrition. Incorporating goodly amounts of com post into the soil will increase the water-holding capacity, increase soil porosity, increase beneficial soil microorganisms, and increase soil fertility – sounds like a good idea. Cucumbers can be grown in rows or in hills with 2-3 plants per hill. In rows, plants should be planted or thinned to 12”-14” apart with rows spaced 3’-4’ apart. Cucumber fruits are straighter and less susceptible to fruit rot if plants are trellised. One gram of cucumber seed contains about 25-30 seeds. Properly stored seed will remain viable for 3+ years.

Culture

As mentioned above, a soil test is the most accurate method of determining what nutrients need to be added to your soil for the crop you are growing. Cucumbers are heavy feeders as are most vegetables. Follow the recommendations made on your soil test results. In lieu of a soil test, incorporate about 1 cup of 10-10-10 per 10 ft 2 at planting. This will usually provide all the phosphorus and potassium needed for one growing season. However, plants will need additional nitrogen during the growing season. Side-dress with 3 oz. (ca. 9 Tbs.) of calcium nitrate (15.5-0-0) or the nitrogen equivalent for every 10 row feet or about 1 Tbs. per plant when the plants start to vine and again in 3 4 weeks. To maintain healthy productive plants during the growing season, side-dress with calcium nitrate every 3-4 weeks. Because nitrogen is easily leached from containers, container grown cucumbers should be provided with 1 Tbs. of calcium nitrate per 10 gallon container every 2 weeks.

Cucumber plants are tender annuals and the fruit is 95% water, so it makes sense that they require regular watering (rain or irrigation) to maintain health and production. During dry periods, inground plants will require irrigation about every three days (depending on soil water holding capacity) and every day if growing in containers. Cucumber vines will wilt when water-stressed and may show wilting on very sunny hot days even if the soil is moist. Fruit produced when plants are water-stressed tend to be more bitter. In our area, irrigation is generally required, not optional.

Harvest

Once production starts, properly maintained cucumber plants should be harvested daily but should never go longer than 2-3 days without being harvested. This is important for fruit quality and to maintain production. If fruits are allowed to mature on the plant, the plants tend to stop flowering. Therefore, overly mature fruits should still be picked and disposed of when found. The size of the harvestable fruit will depend on variety. Picklers and cocktail varieties are usually in the 2”-4” range and slicers and thin-skinned varieties are usually in the 8”-14” range. However, the fruit should be firm with a slightly tender skin no matter what variety is being grown.

Harvested fruit should be refrigerated immediately to remove field heat and can be stored for about 2 weeks in the refrigerator. Optimal storage conditions are 45 50oF at 95% humidity.

Cucumbers can be consumed raw in multiple ways and are stored as pickles. Though there are varieties developed especially for pickling, any cucumber variety fruit can be used to make pickles. Smaller, less mature fruit are best for pickling. You need 2-3 plants per person for a continuous supply of fresh cucumbers, depending, of course, on how many cucumbers you’ll eat. You’ll need more if you plan to make pickles.

Pollination

Most cucumber varieties are monoecious – have both male and female flowers on the same plant. Male flowers usually form and open about 10 days before female flowers at the beginning of the season. Both are produced regularly throughout the growing season. Cucumbers are self-fertile so pollen from the male flowers will pollinate the female flowers on the same plant.

Some cucumber varieties are gynoecious – they pro- duce only female flowers. These varieties were developed to increase production. If you buy these varieties, the seed packet will also contain a few seeds, separately packaged, of pollinator plants. Unless you’re depending on your neighbor’s cucumbers for pollination, you should always include pollinator plants in you garden plan if growing gynoecious varieties.

Parthenogenic varieties have also been developed. These varieties do not require pollination for fruit set Unpollinated fruit will be seedless. The female flowers of these varieties can be pollinated and the fruit will then have seed. There are also parthenocarpic gynoecious varieties. These varieties produce only female flowers and do not require pollination for fruit set.

Recommended Varieties: Many cucumber varieties do well in our area and, if you find one that interests you, you should give it a try. Here are some varieties that have been LSU AgCenter tested in our area and proven to do well.

Slicers: Dasher II (ALS, ANT, CMV, DM, PM), Diva (PM, DM), Fanfare (ANT, DM, PM), General Lee (CVM, DM, PM), Intimidator (ALS, ANT, CMV,), Olympian (ANT, DM, PM), Poinsett 76 (ANT, DM, PM), Rockingham (ANT, CMV,PM), Salad Bush (CMV), Speedway (ALS, ANT, CMV, DM, PM), Sweet Slice (CMV, DM, PM,WMV, ZYMV), Sweet Success (AAS, CMV,WMV), Talladega (ALS, ANT, CMV, PM, WMV), Thunder (ALS, ANT, CMV, DM, ZYMV)

Picklers: Calypso (ALS, ANT, CMV, DM, PM) The letters following the variety name indicate genetic disease resistance:

ALS=Angular leaf spot;

ANT=Anthracnose;

CMV=Cucumber mosaic virus;

DM = Downy mildew;

PM=Powdery mildew;

WMV=Watermelon mosaic virus;

ZYMV=Zucchini yellow mosaic virus.

Common Diseases

Always read and follow label instructions on pesticides.

Angular leaf spot: caused by a bacterium (Pseudomonas syringae pv. lachrymans). Symptoms: Lesions on the foliage begin as water-soaked spots that later turn gray or tan. Spots may initially develop a yellow halo. As the affected tissue dries, the internal tissue may fall out, giving the leaf a tattered appearance. The lesions are delimited by veins, giving them an angular shape. Fruit lesions are usually superficial. The disease is favored by high humidity. The bacterium survives in plant debris and spreads easily. Control: Plant resistant varieties. Fixed copper sprays can slow its spread.

Anthracnose – caused by fungus (Colletotrichum or biculare). Symptoms: Brown roughly circular lesions with yellow edges on leaves, petioles, stems and/or fruit. Generally on older leaves. Lesions dry out and drop out of leaves. Lesions on fruit are sunken. The disease is favored by warm temperatures and wet weather. Control: Plant resistant varieties. Chlorothalonil and mancozeb are chemical fungicides labeled for this disease.

Bacterial Wilt: caused by a bacterium (Erwinia tracheiphila). Symptoms: Individual runners or whole plants begin to wilt and rapidly die. Infected runners appear dark green in color but rapidly become necrotic as the disease progresses. The bacterium is spread by cucumber beetles (striped, banded, and spotted) and overwinters in the insect gut. Control: No resistant varieties. Control the cucumber beetle using insecticides. No pesticides are available for controlling the bacterium.

Common Cucumber Diseases: A- Powdery Mildew (leaf top); B- Powdery Mildew (leaf underside); C- Downy Mildew; D- Angular Leaf Spot; E- Anthracnose; F- Bacterial Wilt

Downy Mildew: caused by the water mold (fungus like microorganism) Pseudoperonospora cubensis. Symptoms: Downy mildew is one of the most common leaf diseases of cucumbers. Symptoms typically begin as small irregularly shaped yellow areas on the upper leaf surface that expand and become brown with age. Affected areas may grow together, and the entire leaf may wither and die. Infected plants also develop a gray mold on the lower leaf surface especially in high humidity. The disease is favored by moderately warm wet weather. Control: Plant resistant varieties. Fungicides labelled for control include chlorothalonil, mancozeb, and fixed copper.

Powdery Mildew: caused by the fungal pathogens Podosphaera xanthii and Erysiphe cichoracearum. Symptoms: A white powdery growth appears on the upper leaf surface. Infection generally starts on the lower leaves and then progress upwards. As the disease progress, white fungal growth covers whole leaves and stem. Disease development is favored by dry conditions, but high relative humidity is required for infection and spore survival. Control: Plant resistant varieties. Fungicides containing chlorothalonil, or sulfur are labelled for control. Neem oil and horticultural oil have also shown effect.

Common Virus Symptoms. A- Mosaic & Mottling by CMV; B- Common Mottling by TRSV; C- Common Distortion by ZYMV

Viruses: Cucumbers are susceptible to several plant viruses including cucumber mosaic (CMV), tomato ringspot (TRS), watermelon mosaic (WMV) and zucchini yellow mosaic (ZYMV) virus. Symptoms: Disease symptoms of plant viruses are mainly stunting of plants, mosaic and mottling of leaves, and leaf deformation. Control: Plant resistant varieties. Remove weeds, which may harbor plant vi ruses and insect vectors. Manage insect vectors with insecticides.

Common Insects found on Cucumbers. A – Green Peach Aphid, B – Melon Aphid, C – Western Striped Cucumber Beetle, D – Western Spotted Cucumber Beetle, E – Banded Cucumber Beetle, F – Pickleworm larva in fruit, G – Hole in fruit made by pickleworm.

Common Pests - Always read and follow label instructions on pesticides.

Aphids (Peach aphid, Melon aphid) Myzus persicae, Aphis gossypii: Aphids are found mostly on the leaf underside. They are piercing-sucking insects that cause plant stress and reduced vigor. Infested leaves curl downward and may turn brown and die. The melon aphid is also a vector of Cucumber Mosaic Vi rus. Control: Aphids are controlled naturally by predatory insects like ladybeetles and assassin bugs. Insecticides containing pyrethrins, bifenthrin, or malathion are labelled for control. Horticultural oil and insecticidal soaps are also effective.

Cucumber beetles (Western striped cucumber beetle Western spotted cucumber beetle, Banded cucumber beetle) Acalymma vittate, Diabrotica undecimpunctata, Diabrotica balteata: These are chewing insects that show feeding damage on leaves, stems and petioles. These beetles primarily cause damage as vectors of the bacterial wilt bacterium. Control: Insecticides containing pyrethrins, carbaryl, or bifenthrin are labelled for beetle control. Kaolin clay has also been shown to be effective if populations are low.

Pickleworms (Diaphania nitidalis): Pickleworm damage occurs when the moth caterpillars tunnel in flowers, buds, stems and fruits. They prefer the fruits. Frass (sawdust-like insect waste) often protrudes from small holes in damaged fruits. Flowers, buds and sometimes entire plants may be killed. Control: Insecticides containing Bt, Spinosad, pyrethrins, carbaryl, or bifenthrin are la belled for control. Neem and horticultural oils have also been effective.

Table 1: Cucumber nutrient content per 100 gram serving which is 3.5 oz. (about one medium cucumber). USDA National Nutrient Data Base

Selected References Cucumber Factsheet. 2023. Clemson University. Pub. HGIC 1309. Cucumber – Key Growing Information. 2023. Johnny’s Selected Seeds. https:// www.johnnyseeds.com/ growers-library/vegetables/ cucumbers/cucumber-key growing-information.html Cucumber, Squash, Melon & Other Cucurbit Diseases. 2016. Clemson University. Pub. HGIC 2206 Cucumber Types and Terminology. 2020. Johnny’s Selected Seeds. Pub. 8989. https:// www.johnnyseeds.com/growers-library/vegetables/ cucumbers/cucumbers-types-terminology.html Fontenot, K. et.al. 2017. Vegetable Gardening Tips – Cucumbers. LSU AgCenter. Pub. 1981. Louisiana Vegetable Planting Guide. 2020. LSU AgCenter. Pub. 1980. Easy Gardening – Cucumbers. Texas A&M. EHT-033