Growing Kale in West Virginia

Kale is a member of the Brassica oleracea family along with broccoli, cauliflower, cabbage and Brussels sprouts. It can be cooked and prepared like collard greens or cabbage and tender leaves can be used in a salad like spinach. Known as a nutritional “powerhouse”, it has gained popularity in recent years because it can also be added to smoothies or juices to add vitamins and minerals. A cool season plant, kale can be grown in West Virginia in spring or fall and can be harvested as early as 30 days. Harvest can continue throughout the season. Some varieties of kale also have ornamental value, adding color, height and texture to the landscape.

Soils

Loose, well-drained soil will encourage kale to develop a more extensive root system which will increase water and nutrient uptake, increasing overall plant growth and health. Rocky or compacted soils inhibit this growth. Prepare soil by tilling at least 10 inches deep and removing weeds and rocks. Work the soil, adding compost and fertilizer based upon soil test recommendations. Free soil testing is available to West Virginia residents from the WVU Soil Testing Lab. More information on how to test your garden soil and a video on how to take a garden sample can be found here. Your soil test will indicate the amount of nitrogen, potassium and phosphate needed in your soil for optimum production. Phosphorus is needed for root growth among other things and is typically applied during planting. Potassium is necessary for water and nutrient movement; nitrogen is necessary for tissue growth. Potassium and nitrogen will likely need to be applied a few times throughout the season. Complete fertilizers (such as 10-10-10 or 20-10-20) will supply all three nutrients in a specific ratio. Your Extension agent can help you choose one that suits your needs best.

A lot of soil in West Virginia is acidic. Since kale grows best with a pH of 6.0 to 6.5, your soil test may indicate lime to increase pH. Lime is best applied in the fall for a spring crop as it takes three to five months to effectively neutralize pH. Dolomitic (agricultural) lime will supply calcium and magnesium if your test indicates you need those nutrients as well. Nutrient deficiency such as nitrogen or calcium can cause symptoms like yellowing or distortion of leaves. More information about symptom of nutrient deficiencies can be found here. 

Raised beds are another option that work well for kale and other greens. Raised beds allow for planting earlier as the soil warms quicker than the ground. Regardless of which option you choose, weed control is important, particularly until plants are established so that weeds don’t out compete the new kale seedlings. After planting continue to cultivate around the kale carefully to remove weeds or hand pull them without damaging kale’s root system. Straw or other mulch can reduce weeds, maintain soil temperature, and retain moisture but it is essential that it comes from a reputable source to ensure that it is herbicide free.   

Production

Kale is a cool weather crop that can be grown in West Virginia in spring and fall. Kale that will be harvested as tender baby leaves are generally directly sown whereas those that will be harvested full size are often transplanted. If you are growing full size kale and would prefer to direct sow them, thin to 9 to 12 inches apart (depending upon variety) once they reach 2 or 3 inches tall.  Not allowing enough space between plants will prevent root growth. Starting the seeds inside and transplanting them will ensure a harvest about a month earlier than if plants were direct seeded. After seeding in either spring or fall, seeds take two to three weeks to germinate; seeds will not germinate if soil is too cold or too dry. 

Sow spring seeds for transplants mid-February or direct seed in early April. Fall seeds should be started around July 17. Kale grows best at temperatures below 65 F and can tolerate cooler temperatures better than hot ones. Temperature extremes can also lead to bolting where the plant will shift energy to premature flower production.   

Watering

Dry days are more common in peak summer so cool season crops are less likely to experience drought. However, soil moisture should be monitored. Kale has a high-water content and forms a shallow root system; its tissues will dry out quickly if it does not receive enough water. Yield can also be reduced as it cannot increase leaf area if it is too dry. After planting, seed beds should be kept moist to ensure seeds sprout and once germination occurs plants should be checked daily to determine if watering is needed.  

Harvest and Storage

Kale can be harvested as baby greens after 30 days of seeding or mature in 55 to 75 days depending upon the variety and desired usage. Large leaves are often tough and should generally be cooked or processed while small tender leaves can be suitable for use in salad. Some varieties sweeten after a frost and are best harvested then. Many varieties allow a harvest of the outer or lower leaves while the inner or upper leaves continue to grow for an extended harvest.     

After harvest, discard leaves that are discolored or have any insect or disease damage. At ideal storage temperature just above freezing (around 34 F) and a humidity of 95%, kale will remain fresh for up to two weeks. In the average home refrigerator storage life is less than a week. Kale should not be kept near ripening fruits such as apples or tomatoes as the ethylene they produce will speed decay of the greens. 

Varieties

Nutrition

A serving of kale is typically one cup raw (21 g) or ½ cup cooked. It is low in sodium, cholesterol and saturated fat. Like many vegetables, kale has a high-water content (85% to 90%) and it also has a small amount of protein (around 2 grams per serving). Kale is high in fiber for digestive health and is high in vitamin K which is essential for blood clotting and wound healing. It is high in Vitamin A for healthy vision and skin health and Vitamin C for iron absorption. Both these vitamins are antioxidants which help overall immunity and protect cells from damage. Kale is also rich in minerals such as calcium and potassium for bone development and muscle contractions. The nutritive value of kale can vary by variety and by how it is prepared; some phytonutrients (vitamins and minerals that are active in plants) are degraded at high heat. For optimum nutrition, choose dark colored varieties and consume them raw or steamed. Avoid frying. Kale is often referred to as a “superfood” and can add nutrition to smoothies, juices, dips or dried or baked as kale chips. 

Cooking and Preserving

Kale will maintain peak quality in the refrigerator for up to seven days; do not wash it until you are ready to use it as the moisture will increase spoilage rate. Tender kale leaves can be used in salads, but the stems should be removed from some of tougher varieties; it may help to slice the kale in small strips. Raw kale is excellent as an ingredient in juices and smoothies, adding nutrition and fiber. Kale can be prepared like other greens such as collards or steamed and seasoned with lemon juice, olive oil, salt and pepper. Steamed or wilted kale is also delicious with walnuts and raisins. Chopped fresh or frozen kale can be added to a soup, stew, or stir fry recipe. Kale can be added to a pasta or noodle recipe in the last five minutes of cooking. Kale chips are particularly popular; remove stems and drizzle chopped fresh kale with olive oil, sprinkle with seasoning, then bake on a cookie sheet until crisp. 

To freeze kale, wash leaves and remove stems. Boil for two minutes then blanch in ice water to preserve color, flavor and texture. Drain and cool. Leave ½ inch headspace in freezer container. Frozen kale has a storage life of one year. Kale can also be pulped or juiced and then frozen for later use in smoothies or juice drinks. One option is to freeze in ice cube trays then empty the kale juice “cubes” into a freezer bag. Individual cubes can then be removed and added to the blender as needed.   

If you would prefer to can kale, it must be pressure canned; it is not safe to process by a water bath canning method as it is a low acid food. Canned kale is a perfect addition to baked dishes, soups or pastas. Wash kale thoroughly and discard stems and ribs. Steam until wilted (three to five minutes) then pack loosely into jars leaving 1 inch headspace. Pour in boiling water, maintaining headspace. Wipe the rims of the jar then put on lids. Process pints for 70 minutes or quarts for 90 minutes at 10 pounds for a dial gauge or 11 pounds for a weighted gauge. 

To dry kale, wash leaves and remove stems. Water blanch for best quality and blot dry. Dry at 130 F to 140 F for several hours until crisp. Drying in a dehydrator with an air circulating fan will speed drying time. Store in an airtight container for six to 12 months. The quality of dried kale is lower than other preservation methods; dried kale is suitable for recipes where texture is not as important and reconstituting in liquid will occur such as soups and casseroles. 

Pests, Diseases and Other Issues

There are several pests, diseases and disorders that are possible in kale for West Virginia home gardeners. Good Integrated Pest Management (IPM) practices such as choosing appropriate varieties, crop rotation, weed management, monitoring often for pests and diseases, addressing problems when necessary and other practices to maintain plant vigor can help minimize issues. Appropriate watering including watering in the morning and watering the soil around the plant instead of plant leaves can help prevent some diseases. Early insect control can also limit some diseases that spread by insect movement.  

Several pesticides are approved for use on kale. Pesticides should be avoided unless necessary as most of the plant is intended for consumption. Spinosad is a pesticide whose active ingredient is a natural substance made by a soil bacterium that can be toxic to insects. Bacillus thuringiensis (Bt) is an insecticide made from a bacterium of the same name which only affects insects consuming that target plant; therefore, it is safe for use around pollinators. Neem oil or insecticidal soap can be effective for some insects and their larvae. Contact your local WVU Extension office for pest and disease identification and recommendation of appropriate pesticides for your situation. 

USDA nutrient information https://www.fda.gov/food/food-labeling-nutrition/nutrition-information-raw-fruits-vegetables-and-fish   

Vegetable Varieties Recommended for West Virginia https://extension.wvu.edu/files/d/efe1bf03-9296-449c-8027-fff3e359d769/vegetable-varieties-recommended-for-west-virginiazx.pdf 

Preserve It Fresh,  Preserve It Safe: 2021, No. 3 Kale  from University of Missouri Extension https://extension.missouri.edu/publications/hes140  

Preserving Greens from Penn State Extension  https://extension.psu.edu/preserving-greens  

Author: Jodi Richmond, WVU Extension Agent – Mercer County

Last Reviewed: January 2024

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