Okra (Abelmoschus esculentus) is one of the iconic southern vegetables that every gardener should grow. It is a nutritious easy to grow veggie that can double as an attractive landscape ornamental. (See GNO Gardening May 2018 for previous article on okra).

As shown here, okra is a low-calorie vegetable that is high in fiber, Vitamin C, Vitamin B6, calcium, magnesium, potassium and even almost 2g of protein.

Table 1: Nutritional content of okra. USDA National Nutrient Database

In fact, okra has over 40% as much Vitamin C as citrus and only 15% of the sugar.

Research on different parts of okra plants have shown nutraceutical properties that include: antibacterial, anticancer, antidiabetic, antioxidant, gastroprotective, immunomodulatory, lipid lowering, neuro-pharmacological, and trypsin inhibition.

Botany

Okra (Abelmoschus esculentus) is a member of the Malvaceae or mallow family which also includes such ornamentals as Hibiscus, hollyhocks, musk mallow and rose-of-sharon as well as economically important food, fiber and lumber plants like cotton, cocoa, cola tree, durian fruit, jute, linden (basswood), and balsa wood and such natural wonders as the baobab and bottle tree.

Okra is a perennial plant in tropical environments but is most often grown as an annual. Many commercial okra varieties grow as tall plants with a central main stem and minimal lateral branching. Varieties have been selected that produce a central main stem but have prolific lateral branching. Depending on variety, okra can grow from 4’-12’+ tall. During cultivation, you can top okra plants if they are getting taller than you want. This will encourage lateral branching creating a bushier plant.

Okra plants have a deep tap root system. Okra leaves are arranged alternately with long petioles. The leaves are heart-shaped (chordate) with three to five deep lobes and palmate venation and generally hairy. Leaves are light to dark green; purple or burgundy varieties have purplish petioles. Young okra leaves may be cooked similarly to the greens of beets, spinach or dandelions, or used raw in salads.

Okra produces showy 1.5”-3.0” diameter flowers. The attractive complete flowers (having sepals, petals, stamens and pistils) are white to light yellow with a crimson center. Okra is self-fertile. Okra flowers are produced continually throughout the growing season. The flowers have 5 sepals and 5 overlapping petals. The stamens are numerous and united to form a tubular sheath which surrounds the pistil except for the exposed style and stigma at the tip. The style varies in length and splits near the apex into 2-9 parts corresponding to the number of carpels. An individual flower will open just after sunrise.

Okra flowers are edible and can be used similar to squash flowers.

The fruit or “okra pod” is an elongated, conical or cylindrical capsule, comprising for the most part, five cavities containing ovules. It is generally ribbed though smooth-podded varieties are available. Cultivated okra varieties for the most part are spineless. The fruit is normally yellowish green to green, but is sometimes purple or whitish green depending on variety.

Figure 1: A - Okra leaves from Candle Fire (L) and Burgundy (R), B – Okra flower, C – Okra pods from Candle Fire (L) and Burgundy (R), D – Okra pods cut vertically and longitudinally. Note the abundant immature seed. E – Mature okra seed.

The okra pod contains numerous round to oval, smooth, striated and dark green to dark brown seeds about the size of a BB – about 0.2” in diameter. Okra seeds may be roasted and ground to form a caffeine free substitute for coffee.

Site

Okra is a sun-loving, heat-loving vegetable growing best in southern climates. Optimal soil conditions is a well-draining, light sandy to medium loam, high in organic matter with a pH between 6.0 and 6.8. However, okra will grow and produce in a wide range of soil conditions including clay soil. A full sunlight location with 8 or more hours of sun daily is ideal. Soil temperatures should be at least 65o F with optimal growth occurring at soil temperatures between 75–90o F.

Though not regularly grown in containers, okra will perform very well in containers of 5 gallons or more especially if using the shorter bushier varieties.

Planting

Okra can be direct-seeded into the garden or started early in the greenhouse and planted as transplants. Plant the seed 0.5”-1” deep. Okra seed have a hard seedcoat. Soaking the seed overnight in water or abrading gently with sandpaper prior to planting will enhance germination. Rows should be 3’ apart and plant final spacing should be about 18” (spacing may be adjusted depending on variety).

Soil temperature should be higher than 65o F before planting seed or transplanting seedlings. For southern Louisiana, that’s usually from mid-March till the end of May for Spring planting. Optimal seed germination temperature is 75-90o F. Seedlings will emerge in 5-14 days depending on the soil temperature and variety. When purchasing seed, it’s good to know that there are about 20 okra seeds per gram. If stored properly, seed will remain viable for 2+ years. Days to maturity depend on variety but range from 50-80 days.

Culture

Okra is a heat-loving vegetable that continues to produce a nutritious abundant crop right through the hottest summer as long as it gets the nutrients and water it needs.

Always do a soil test prior to planting your vegetable garden to determine what nutrient supplements need to be added. If you don’t do a soil test, the general recommendation is to incorporate 1-1.3 lb. (2-2.6 cups) of 8-8-8 per 100 ft2 at planting. Like most of our vegetables, okra is a heavy feeder and should be side dressed with 2/3 lb. (3/4 cup) of calcium nitrate (or nitrogen equivalent) per 100 ft2 at first fruit-set and every 4-6 weeks thereafter until frost.

For optimal production, okra needs about 1.5” of water every 7-10 days which is about 3 quarts of water per square foot. Flowrate depends on a lot of variables – water pressure, hose diameter, hose length, hose end attachment, etc. Make it simple – water thoroughly and deeply once a week if there is little to no rain. If growing in containers, water once to twice daily during active production.

Harvest

To maintain production and get the highest quality pods, okra should be harvested every 1-2 days. Pods are best when 2”-4” long. Tender edible pods will easily snap from the plant. You can also harvest by cutting the pods. Most varieties tend to get fibrous and inedible if longer than 6”. However, smooth pods (as opposed to ribbed pods) tend to be less fibrous as they grow and can generally be harvested at lengths up to 8” and still be tender. It is a good practice to wear long sleeves when harvesting to avoid skin irritation from okra’s leaf trichomes.

As mentioned earlier, you can also harvest young leaves to eat as greens or flowers to eat as well. The best storage conditions for harvested pods is 45- 50o F and 90-95% relative humidity or 3-5 days in a normal refrigerator.

For a continual supply of fresh okra pods for eating, you’ll need 2-3 plants per person. If you want to make pickled okra or preserve for winter eating you’ll need more.

Pollination

Okra flowers are complete and self-pollinating. Okra flowers are regularly visited by bees and other pollinators so they may also be cross-pollinated.

Recommended Varieties

Louisiana climate is ideal for okra production and I’ve never seen a variety yet that failed to produce. However, based on variety trials done by LSU AgCenter, the following varieties are recommended: Ribbed – Clemson spineless, cowhorn, Annie Oakley, cajun delight, burgundy, Lee, Louisiana green velvet, jambalaya; Smooth – emerald, candle fire.

Specialty varieties:

Container varieties (these varieties are shorter and bushier): jambalaya, baby bubba, dwarf long green, cajun jewel, cow’s horn. White podded varieties: blondy, silver queen. Red/purple podded varieties: burgundy, candle fire, bowling red, carmine splendor.

Common Diseases

label instructions on pesticides).

Cercospora Leaf Spot: caused by Cercospora abelmosch and Cercospera malayensisi. Symptoms: Most of the disease is on the leaf underside. On the top of the leaves, only small spots are visible. On the bottom of the leaves, yellow to brown spots can be seen. The spots are limited by leaf veins. In general, Cercospora leaf spots are favored by frequent rain or heavy dew and temperatures below 90°F. Control: Fungicides containing chlorothalonil or tebuconazole have been shown to be effective.

Powdery mildew: caused by fungus Oidium asterispunicei. Symptoms: Powdery white covering on leaves. Patches may coalesce to cover the entire plant. If plant is heavily infected, leaves may roll upward and appear scorched. Pathogen overwinters on plant debris or an alternate host. The disease emergence is favored by warm, dry weather with cool nights that result in dew formation. Control: Fungicides containing chlorothalonil or copper hydroxide have been shown to be effective. Neem oil is an alternative choice for organic gardeners.

Common Pests

instructions on pesticides).

Caterpillars (armyworms (beet, southern, and fall), cabbage looper, and corn earworm) (Spodoptera exigua, Spodoptera eridania, Spodoptera frugiperda, Trichoplusia ni, Helicoverpa zea): The larvae of these lepidopteran insects chew on the leaves and cabbage looper and corn earworm will also bore into the stem. Regular scouting for damage is the best means of monitoring. Control: All of these insect larvae are effectively controlled using B.t. or Spinosad. Insecticides containing carbaryl or bifenthrin are also effective.

Aphids (Green peach aphid, Melon aphid) (Myzus persicae, Aphis gossypii): Aphids are found mostly on the leaf underside and on succulent leaf tissue. They are piercing-sucking insects that cause plant stress and reduced vigor. Infested leaves may be deformed. Control: Aphids are controlled naturally by predatory insects like ladybeetles and assassin bugs. Insecticides containing pyrethrin, bifenthrin, imidacloprid, or malathion are labelled for control. Horticultural oil and insecticidal soaps are also effective.

Silverleaf Whitefly (Bemisia tabaci): Whiteflies are piercing-sucking insects that are found primarily on the leaf underside. Heavily infested plants may be severely weakened. Adult insects create a white cloud of flying insects when an infested plant is disturbed. Control: Insecticides containing malathion, bifenthrin, imidacloprid, or pyrethrin are labelled for control of whiteflies. Azadirachtin, and horticultural oil are also effective and more suited for organic gardeners.

Southern Root-Knot Nematode (Meloidogyne incognito): Nematodes feed on plant roots by piercing the root with their stylet (syringe-like mouth) and causing the root to create protective galls around the nematode. This inhibits root growth and function with the generally symptomology of weakened, stunted, yellowing plants with greatly reduced growth and production. Control: There are no chemicals labelled for nematode control in the home garden. Solarization of infested beds can greatly reduce nematode populations.

Red Imported Fire Ants (Solenopsis invicta): The prevailing thought has been that ants did not hurt okra and were mainly visiting okra plants to get honeydew produced by aphids or other sucking insects. That has changed with the advent of the imported fire ant. Fire ants feed on the base of developing blooms before the bloom buds open causing them to abort. Control: Applying an ant bait is the most effective means of managing fire ants in a vegetable garden. Baits are a granular material that includes an insecticide and an attractant, usually soybean oil. The ants collect and carry the granules back to the colony where the insecticide kills colony members. A single bait application can reduce fire ant populations by around 80%. Baits that contain bifenthrin or Spinosad have been shown to be effective. Be sure to use only baits that are specifically labeled for use in vegetables.

Selected References:

Elkhalifa, A.E.O. et. al. 2021. Okra as a potential Dietary Medicine with Nutraceutical Importance for Sustainable Health Applications. https:// pubmed.ncbi.nlm.nih.gov/33525745/

Fontenot, K. et. al. 2020. Louisiana Vegetable Planting Guide. LSU AgCenter pub. # 1980. Hayes, B. 2022. 19 Best Okra Varieties To Grow In Your Garden Or Container. file:///D:/Joe's%20LSU% 20Computer%20Files/LSU%20AgCenter% 20Publications/Vegetables/Okra%20-%2019% 20Best%20Okra%20Varieties%20To%20Grow% 20In%20Your%20Garden.pdf

Noling, J.W. 2019. Nematode Management in Okra. UF-IFAS pub. #ENY-043 Okra Growing Guide. 2023. Territorial Seed Company. https://territorialseed.com/blogs/springgrowing-gu...

Qureshi, J. A. et.al. 2003. Insect Management for Okra. UF-IFAS pub. # ENY-466. Tripathi, K.K. et. al. 2011. Biology of Abelmoschus esculentus L. (Okra). https://biosafety.icar.gov.in/wpcontent/uploads/20...

Figure 1: A - Okra leaves from Candle Fire (L) and Burgundy (R), B – Okra flower, C – Okra pods from Candle Fire (L) and Burgundy (R), D – Okra pods cut vertically and longitudinally. Note the abundant immature seed. E – Mature okra seed.