COLLARD VARIETIES (approximately 60-80 days depending on planting date and variety).

Blue Max, Georgia Southern, Heavi-crop, Top Bunch, Vates. For trial: Morris Heading, Carolina, and hybrids: Hi Crop, Green Glaze (some resistance to imported cabbage worm, diamondback moth, and cabbage looper reported).

KALE VARIETIES (approximately 50-60 days).

Vegetable Kale: Darkibor, Dwarf Siberian, Vates Blue Curled, Dwarf Curled Scotch. For trial: Blue Ridge, Dwarf Green Curled, Improved Vates, Redbor, Starbor, Tall Scotch, Vates Dwarf Blue.

Chinese Kale (also known as Chinese broccoli), also called Gai Lohn or Kailaan: This vegetable is more like broccoli, except the fleshy stalk is harvested with tender leaves and eaten just as the flowers begin to open (grown like broccoli, see file on broccoli): Gai Lohn, Green Lance Hybrid.

Broccolini: a hybrid of standard broccoli (Brassica oleracea var. italica) with Chinese kale (Brassica oleracea var. alboglabra), which resembles long, slender broccoli side shoots that are nearly ready to flower. The flavor has been described as similar to broccoli but sweeter and less pungent or as resembling asparagus. This hybrid was developed by Sakata Seed Co. and is grown and marketed exclusively in the United States by Mann Packing Co. and Sanbon LLC of California.

Flowering, or ornamental kales (sometimes called flowering cabbage): Nagoya Red, Nagoya White, Red Pigeon, White Pigeon. For trial: Sekito Rose Bouquet, White Lady. These may be marketed as garnishes in salad bars or as ornamental plants.

Novelty: Walking Stick Cabbage (kale). Used to make walking sticks with character! Thompson & Morgan Seed Co., POB 1308, Jackson, NJ 08527, provides seed and instructions.

SEEDING

Collard and kale seed numbers about 144,000/lb. Plant seed 0.5 inch deep. Use hot-water treated seed and fungicide treat seed to protect against several serious seed-borne diseases. Hot water seed treatments are very specific (122 F exactly, for 25 to 30 minutes; the wet seed then quickly cooled and dried). The seed treatments are best done by the seed company, and can usually be provided upon request.

For collards, seed the spring crop in April, fall crop in July. If direct seeding, space rows 2 to 3 feet apart with 4 seeds per foot, 2-4 lb seed/acre. When plants are 2-3 inches tall, thin them to a spacing of 12 to 24 inches apart. If transplanting, transplant when the plants are 6-8 inches tall and plant 12,000 to 14,000 plants/acre.

For kale, seed a spring crop as early as possible and seed a fall crop from July to early August. Space 1-3 feet between rows and 3-10 inches between plants. Use 3-5 lb seed/acre of "Scotch", and 1.5 lb/acre of "Siberian" types (see above for descriptions).

Most kale in the Willamette Valley is now transplanted using greenhouse-grown plugs.

SOIL

Well-drained loams relatively high in organic matter are suitable for collards and kale. Cover crops may be turned under to maintain organic matter. The desirable pH is between 5.5-6.5. If the pH is too high, manganese is frequently unavailable which results in a chlorotic condition of the leaves. If the pH is too low, an application of lime is recommended.

FERTILIZER

The following recommendations are general. It is advisable to have a soil test done for each field to be planted. For more information on fertilization and lime requirements for collards, kale, and other cole crops, see Broccoli.

Nitrogen: 60-100 (N) lb/acre (1/2 at planting and 1/2 at thinning)
Phosphorus: 80-120 (P205) lb/acre
Potassium: 60-120 (K20) lb/acre
Sulfur: 30-50 (S) lb/acre
Boron: 0-4 (B) lb/acre
Magnesium: As indicated by soil test (may need 60-120 lbs MgO per acre)
Copper, boron, and zinc - as indicated by soil test.

IRRIGATION

Maintain uniform soil moisture for tender growth and maximum use of soil nutrients. As much as 12-14 inches of water may be needed. Soil type does not affect the amount of total water needed, but does dictate frequency of water application. Lighter soils need more frequent water applications, but less water applied per application.

HARVESTING AND HANDLING

The University of California-Davis has a file on Minimal Processing of Fresh Vegetables that discusses film wrapping and other topics.

An approximate yield for collards is about 150 cwt/acre. Collards are considered to be mature when a large rosette of leaves form in the crown of the plant. The plants may be harvested by machine or cut by hand. Grade the harvested plants by removing decayed or damaged leaves. Generally four wrapper leaves are left on to protect the center rosette.

Kale leaf yield can be as much as 400 cwt/acre. Kale can be harvested three ways: whole plant, bunched leaves, or "stripped" leaves. "Stripped" kale is pre-packaged for fresh market. In all methods, yellow or damaged leaves must be removed before packing. Whole plant harvest in not currently practiced in Oregon. Kale in Oregon is usually harvested on demand 2-4 times over a 4-month period but leaf harvest may be done weekly when demand is high. A skilled laborer can harvest and bunch 4 boxes/hour. Yields are about 3200 dozen 1-lb bunches/acre.

STORAGE (Quoted or modified from USDA Ag. Handbook 66 and other sources)

Leafy greens such as collards, kale, rape, Swiss chard, and beet greens are handled like spinach. Because of their perishability, they should be held as close to 32 F as possible. At this temperature, they can be held for 10 to 14 days. Relative humidity of at least 95 % is desirable to prevent wilting. Air circulation should be adequate to remove heat of respiration, but rapid air circulation will speed transpiration and wilting. Satisfactory precooling is accomplished by vacuum cooling or hydrocooling. These leafy greens are commonly shipped with package and top ice to maintain freshness. Research has shown that kale packed in polyethylene-lined crates and protected by crushed ice keeps in excellent condition for 3 weeks at 32 F but only 1 week at 40 F and three days at 50 F. Vitamin content and quality are retained better when wilting is prevented.

PACKAGING

Collards are packaged in bushel baskets, crates and cartons, 24 pack, 23-24 pounds; 1.4-bu, 23-24 pounds; or crates and cartons, 12-24 bunches.

Kale is commonly packaged 1 or 2 dozen bunches/box. Bunches are 4-8 leaves or about 1 lb each.