Salad mix, mesclun mix and spring mix are interchangeable terms used to describe assorted mixed greens harvested at the seedling stage (3 to 4 weeks). Blends usually include 5 to 7 types of greens with a range of leaf sizes, colors, shapes and textures. Although leaf lettuces are often the primary component, most mixes also include non-lettuce greens, most commonly Brassica species, to add diversity in flavor and appearance. Mixes can be mild or spicy flavored, and can be harvested young for use in salads or older as "braising" mixes for stir-fries.
Brassica crops typically contribute spicy or pungent flavors, while the lettuces and Chenopodium crops are mild and sweet. Chicory family crops are slightly bitter, and along with some herbs, contribute different flavors. Varieties are selected not only for flavor and leaf texture, but also for color. Red varieties that are well suited for salad mix production are those that develop good red color even under low light conditions. For cool-weather or winter production, use the most cold-hardy species such as spinach, Claytonia (Miner's Lettuce), arugula, kale, and other Brassicas. For late fall and winter production, growers should choose lettuce and spinach cultivars with resistance to a wide array of races of downy mildew .
Types and Varieties
|LETTUCES||Red Salad Bowl, Parris Island Cos, Rouge d'Hiver, Lolla Rossa, Tango, Red Sails, New Red Fire, Defender, Outredgous|
|BRASSICA FAMILY||Tatsoi, Kyona/Mizuna, Komatsuna, Broccoli Raab, Tokyo Bekana, Scarlett Frill, Green Wave and other mustards (Brassica juncea), Red Russian Kale (B. napus), Cress (various species), Arugula/Rocket (Eruca sativa), Chinese Cabbage (B. rapa), Broccoli Raab|
|CHENOPODIUM FAMILY||Swiss Chard (Ruby Red, Fordhook Giant), Spinach (Space, Tyee), Beet (Golden, Chioggia, Red), Amaranth|
|CICHORIUM FAMILY||Radiccio, Endive, Escarole|
|HERBS||Dill, Cilantro, Fennel, Basil, Parsley, Salad Burnet Chervil|
Mache/Corn Salad (Valerianella), Dandelion (Taraxacum), Purslane and Claytonia/Miners's Lettuce (Portulaca)
Salad mix crops are short season and require relatively little fertilizer (see Nutrient Table below). Sidedressing is usually not needed. If planted following another crop, additional fertilizer for salad mix may not be necessary.
|PLANT NUTRIENT RECOMMENDATION ACCORDING TO SOIL TEST RESULTS FOR MESCLUN|
|MESCULN||NITROGEN (N)* LBS PER ACRE||PHOSPHORUS (P) LBS P2O5 PER ACRE||POTASSIUM (K) LBS K2O PER ACRE|
|SOIL TEST RESULTS||VERY LOW||LOW||OPTIMUM||ABOVE OPTIMUM||VERY LOW||LOW||OPTIMUM||ABOVE OPTIMUM|
|Broadcast and Incorporate||50||180||120||30-60||0-30||180||120||30-60||0|
|Sidedress 3-4 Weeks after Planting(if needed)||30||0||0||0||0||0||0||0||0|
|*SEE PLANT NUTRIENTS FOR INFORMATION ON NUTRIENT MANAGEMENT AND APPLICATION.|
Salad mixes are typically seeded at high density. Seeding rates vary with seed size and the species, but common spacing is less than 1" between plants with 2" to 3" between rows on 30" wide beds. Seed can be broadcast, but is often seeded 1 to 6 rows at a time using a hand-driven precision seeder. For larger scale production, 17-row mechanical seeders are often used. Germination may take anywhere from 2 to 15 days at the optimum germination temperature (55°F to 70°F). Follow specific germination requirements for each component of the mix. Generally, salad mix components are cool season crops that will germinate poorly when night temperatures are 80°F or higher. Germination of some species can be inhibited by heat and light, shading may be necessary to get adequate germination and growth in mid-summer.
Although seeds of multiple varieties or species can be blended and planted together, different germination times and rates of growth make coordination difficult. Each component of a mix is typically grown separately and mixed after harvesting. Salad mix is made from short-season crops (30-40 days), but the rate of growth varies greatly with species, day length, total light and temperature. The time from planting to harvest will be 2 to 3 times longer for fall (September – February) plantings than for late spring or early summer plantings. Consistent harvest throughout the growing season requires carefully planned succession plantings. Winter production in New England is possible, but low light and cool temperatures make production time longer than in summer, and cold-hardy species should be used. Prolonged exposure to temperatures below freezing (32ºF) will reduce the quality of even the hardiest species.The best way to determine timing is to experiment in your own system, but for recommendations for a starting point see these two publications from Johnny's Selected Seeds: Salad Mix Production (http://www.johnnyseeds.com/assets/information/salad-mix-production-8135.pdf), and the Winter Growing Guide (http://www.johnnyseeds.com/t-winter-growing-guide-high-tunnel-scheduling.aspx).
Harvest and Storage
Greens can be harvested from 3 to 5 weeks after seeding. Flavors intensify and leaf textures change with age, so optimum harvest time will depend on yields required and the intended use of the final mix. Harvesting can be done by hand clipping approximately 1" above the soil line. Mechanical or hand-driven saw-like harvesters with or without vacuums are used for large-scale production. Some varieties will re-grow to permit multiple harvests, but the second harvest will be less uniform and may be of lower quality. For this reason, most growers harvest each planting only once. After harvest, salad mix components are washed, dried and cooled prior to packaging in bags or plastic-lined boxes. Young leaves are tender and susceptible to bruising, and therefore must be handled very gently after harvest. Rapid cooling with near-freezing water will greatly prolong shelf life. Greens are then dried using small salad spinners or custom-made commercial or homemade versions with larger capacity. Salad mix should be stored as close to 32°F as possible with 98-100% relative humidity.