Kale, known for its nutritional prowess and versatility in the kitchen, is a popular choice for home gardeners across the United States. In Washington State, with its varied climate and rich soil, kale can be particularly rewarding to grow. Whether you’re a novice gardener or an experienced green thumb, this guide will walk you through the essential steps to successfully cultivate kale in Washington.
Kale belongs to the Brassica family, which includes other well-known vegetables such as broccoli and cabbage. Its leaves can be curly, flat, or even ornamental, and come in shades of green or purple. The primary varieties of kale include:
In Washington’s climate, all of these varieties can thrive if given the right conditions.
Washington experiences diverse climatic conditions ranging from Mediterranean to maritime maritime climates. While kale is a hardy green that can tolerate cold temperatures, it grows best in cool weather. Optimal temperatures for growing kale are between 60°F and 70°F (15°C to 21°C). However, it can endure frost and even improve in flavor after exposure to cold.
Kale prefers well-drained, nutrient-rich soil with a pH level between 6.0 and 7.5. Here are some tips for preparing your garden bed:
Soil Testing: Before planting, test your soil to determine its pH and nutrient content. Kits are available at garden centers or through local extension services.
Amendments: Depending on your soil test results, you may need to add organic matter such as compost, well-rotted manure, or peat moss to enrich the soil.
Drainage: Ensure proper drainage by avoiding low-lying areas where water accumulates.
You can start kale either indoors or outdoors:
Indoors: Start seedlings about 6 weeks before the last expected frost date (usually mid-April in most parts of Washington). Use seed trays filled with seed-starting mix and provide adequate light.
Outdoors: You can direct sow seeds about 2 to 4 weeks before the last frost date or in late summer for a fall crop. Space seeds about 1 inch apart in rows that are 18 inches apart.
If you started your kale indoors, transplant your seedlings outdoors when they have at least two true leaves and the nighttime temperatures remain above 45°F (7°C).
Spacing: When transplanting, space plants about 12 to 18 inches apart to allow for adequate airflow.
Planting Depth: Ensure that you plant them at the same depth they were growing in their pots.
Watering: Water thoroughly after transplanting to help settle the soil around the roots.
Kale requires consistent moisture but dislikes soggy soil. Water deeply once a week, especially during dry spells. Monitor your plants closely; if they begin to wilt or develop dry leaf edges, increase watering frequency.
To encourage robust growth:
Initial Fertilization: Mix a balanced fertilizer into the soil at planting time.
Mid-Growing Season: After about four weeks of growth, side-dress with an organic fertilizer high in nitrogen (like fish emulsion) to promote leafy growth.
Kale can attract pests such as aphids, cabbage worms, and flea beetles. Here are some preventative measures:
Companion Planting: Interplant kale with aromatic herbs like basil or marigolds to deter pests.
Row Covers: Use floating row covers to physically block pests while allowing light and water through.
Handpicking: Regularly inspect your plants for pests and remove them by hand when possible.
Kale can be susceptible to diseases such as downy mildew and black rot. To minimize risks:
Crop Rotation: Avoid planting kale in the same location year after year.
Air Circulation: Space plants adequately to allow airflow between them.
Watering Technique: Water at the base of the plant rather than overhead to keep foliage dry.
One of the best aspects of growing kale is that you can begin harvesting relatively early:
Kale can be harvested when leaves reach a size suitable for consumption—usually around 6 inches long—generally about 50-60 days after planting.
For a continual harvest, pick the outer leaves first while allowing inner leaves to continue growing.
Cut leaves near the stem using sharp scissors or garden shears but avoid removing more than one-third of the plant at a time.
For an end-of-season harvest before winter sets in (typically late fall), cut entire plants at ground level.
Freshly harvested kale can last about a week in the refrigerator if stored properly:
Place unwashed kale in a perforated plastic bag.
Store it in the vegetable crisper section of your fridge for optimal freshness.
If you have an abundance of kale, consider freezing it after blanching: briefly boil it then plunge it into ice water before packing it into freezer bags.
Growing kale in Washington can be an enjoyable and fulfilling endeavor that yields nutritious rewards throughout several seasons of the year. By understanding its growing conditions, implementing proper care techniques, managing pests effectively, and harvesting correctly, you’ll enjoy bountiful crops of this superfood right from your backyard garden. Whether you use it fresh in salads or cook it into hearty dishes, knowing how to grow kale opens up doors to culinary creativity while enhancing both nutrition and gardening skills!