Lettuce Farming

Family: Asteraceae Genus and Species: Lactuca sativa

The many varieties of lettuce allows it to grow almost anywhere. Given the right soil and climate conditions, a farmer can enhance production and make lettuce farming a viable option. With the recent price increases of vegetables, growing lettuce has become more attractive and a good source of additional income.

According to former Bank of the Philippine Islands (BPI) executive A.S. Tanjanco and now part-owner of Hydrent Ventures lettuce farm, "... you don’t need a big land to be profitable (in lettuce farming). It’s a high-value crop, which means higher margins. We understood many are still not used to eating salads, but there is a very big niche market, especially in Metro Manila, so we decided to tap that. Most of the vegetable salads are still being imported and we can produce that and sell it at more reasonable prices." (Philippine Star, 11 November 2004)

Another advantage of planting lettuce is that it generally like to grow in partial to full shade. Lettuce is best when it is grown quickly and pampered a bit with good soil and adequate moisture so that bolting or sending up a flowering stalk is avoided. It will also prevent the plant from becoming more bitter and tough.

In some countries, lettuce varieties that are heat tolerant are grown in warmer climates grow and cool season lettuces during the fall, winter, and early spring.

Soil

Lettuce likes a partly sunny to shady spot with soil rich in humus that retains moisture. Lettuce grows best in temperatures ranging from 55°-65°. The optimum pH is 6.5 to 6.8.

Spacing

Spacing for lettuce depends somewhat on the kind of lettuce planted. If you are planning to harvest the entire head of lettuce then give the plants more room. For example, lettuce grown to produce heads should be given 8"-12" apart in all directions. Lettuce that will be harvested leaf by leaf should be planted much closer, with ½" between the starts. Spacing can even be random and tight if you intend to harvest the lettuce very young.

Lettuce is pretty forgiving and great crop to use for interplanting - planting in and among other vegetables. Give the main crop room to grow and allow enough space for good air circulation.

Direct Seeding

Lettuce is a good crop for direct seeding. Make sure the bed is prepared well and the soil is moist. Lettuce germinates best in cool soil (40°-60°) and becomes temporarily dormant if it is too hot.

Sow lettuce seeds 1/2" deep in rows 1-1/2" apart. Lettuce plants have a shallow, compact root system. Make sure there are enough nutrients available by mixing in compost before sowing the seeds. Broadcast lettuce seeds over the bed and rake lightly so they are covered with a very thin layer of topsoil for harvest as young lettuce.

Seeding For Transplants

Lettuce can be started indoors for early planting in the spring or for succession planting. Start lettuce seeds in trays with individual cells. Start them under lights if available as lettuce seeds need light to germinate. Be careful not to cover the seeds with soil, gently pressing the seeds into the moist starting mix is enough to ensure good germination. For best results, start seeds one month before planting out. Try to start successive batches of lettuce instead of starting a whole tray or seed package. You will be able to use more lettuce if you have a continuous supply rather than a huge crop ready all at once.

Germination

These seeds germinate best in soils around 40°F-60°F. Germination will take 7-14 days.

Transplanting Into the Garden

Transplant lettuce to the garden when there are at least 4 true leaves on the starts. Make sure the soil is moist before planting.

Watering

Lettuce does not need a lot of water but it does need to be continuously moist. It is important to make sure your lettuce bed does not dry out as this will cause the lettuce to bolt and become bitter.

Growing lettuce in a semi-shaded to shaded location and using a straw mulch around the plants helps retain moisture. Water lettuce with a watering wand and concentrate the water at the base of the plant, not on the leaves. Watering the leaves encourages diseases and may damage some varieties of the more delicate lettuces.

Harvesting

Lettuce grows quickly and is ready before flowers appear. The trick to harvesting lettuce is picking it before it is bitter. If flowering stalks appears, the plant is past its prime.

Lettuce can be harvested as soon as true leaves appear but let the lettuce plants develop enough so that harvesting 3-4 leaves from the outside of the rosette of each plant will not harm the plant's growth. If you are harvesting the whole lettuce head, wait until it is bigger than the size of your fist and harvest the lettuce before it becomes bitter. If in doubt, try a leaf! Harvest either the largest, outside leaves or the whole plant. If harvesting tender young lettuce that is tightly spaced use a pair of scissors to cut the lettuce above the soil line.

Post-Harvest Handling

Clean the lettuce of dirt and cool using hydro cooling. Hydro cooling is the process of spraying or immersing vegetables in chilled water.

Storage

Clean, dry lettuce lasts 3-5 days in optimum conditions though lettuce is best eaten fresh. Lettuce can be stored for 2-3 weeks at 32° and 98 -100 percent relative humidity. Lettuce is very sensitive to ethylene gas so do not store lettuce with vegetables and fruits that give off ethylene gas such as apples and pears.

Diseases and Pests

The most common diseases of lettuce are Big Vein, Damping-Off, Downy Mildew, Mosaic Virus, Nematodes, Sclerotinia Drop, Soft Rot, and Tip Burn.

Pests that are usually attracted to lettuce are Bulb Mites, Cutworms, Darkling Beetles, Field Cricket, Garden Symphylans, Leafminers, Springtails, Armyworm, Beet Armyworm, Corn Earworm and Tobacco Budworm, Loopers, Saltmarsh Caterpillar, Foxglove Aphid, Green Peach and Potato Aphids, Lettuce Aphid, Lettuce Root Aphid, Silverleaf Whitefly, and Slugs.

Financial Return

Hydent Ventures was set-up by Tanjangco, former Unilever marketing guy Nestle Jeturian and information technology specialist Tonito Vargas in 2004 by investing about PhP 9 M in their 1.3-hectare farm. They harvest every 45 days about 3,000 kilos of six leafy lettuce varieties — red and green oak, lollo rossa and lollo biondo, waldmans greens and green ice and romaine. Soon, other vegetables like salad tomato and bell pepper and herbs such as basil will also be grown.

The salad comes in two packages – regular and big. The big one costs PhP 100 and the regular is priced at PhP 75. Orders are made over the phone or through text message placed a day ahead because they prepare the meals at night in time for delivery the next morning.

Hydrent Ventures now supplies supermarkets such as Shopwise (Libis/Makati/Alabang/Araneta) and South Supermarket. It also delivers to hotels such as Dusit Hotel, Pan Pacific Hotel, Heritage Hotel, Manila Hotel, Astoria Plaza, Hyatt Hotel & Casino, Richmonde Hotel, Great Eastern Bellevue Hotel, Traders Hotel, Manila Diamond and Westin Pilippine Plaza. Some of the restaurants and bars it supplies are Windows Café , Gourdos Café & Restaurant, Lumiere, Coffee Bean & Tea Leaf, Oliver’s Super Sandwiches, Bizu Patisserie, Kulinarya, Masas, Cena, Palm Country Club and Vargas Kitchen.

References

Bradley, F. M. and Ellis, B. W.(Ed.). (1992), Rodale's All-New Encyclopedia of Organic Gardening: The Indispensable Resource for Every Gardener, Emmaus, Pennsylvania: Rodale Press.

Johnny's Selected Seeds (2002), "Lettuce", Johnny's Selected Seeds. Oregon State University, Lettuce , Commercial Vegetable Production Guides, Last modified 1999-01-02, Accessed 2003-5-11

Smith, E.C. (2000), The vegetable gardener's bible: discover Ed's high yield W-O-R-D system for all North American gardening regions., Storey Books: Pownal, VT.