Parris Island Cos Romaine Lettuce Seeds

Paris Island Cos romaine lettuce seed produces extremely uniform romaine heads great for market or for the home gardener. This heirloom variety of romaine lettuce has strong attributes suitable for both commercial growing and backyard gardening. Uniform upright leaves, disease tolerance, and bolt resistance are all qualities that are important for Southern California growers and beyond. Originally bred by Ferry-Morse in 1951 for the climate of Parris Island in coastal South Carolina. Enjoy the perfectly shaped romaine leaves with crisp, juicy flavor!

Planting by Zones

Zones 9-10

• Lettuce is a cool season crop that does best in cool temperatures. In Zones 9 and 10 it is happiest during winter and early spring with seasonal rains, but can also be grown year round in mild areas. Row cover and shade cloth can extend the growing season. Lettuce can be easily direct-seeded or transplanted out. Seeds do not germinate well in high temperatures.

Zones 2-8

• Start seeds indoors 3-4 weeks before the last frost. Seeds germinate well at low temperatures of around 40°F but do not germinate well in temperatures over 75 degrees.

Planting Lettuce

• Lettuce is easy to plant directly in the soil or into starter pots and transplanted out.
• To direct sow, plant seeds in well-worked soil that has been deeply watered and is debris-free. Cover with 1/4″ of finely sifted soil.
• If using starter pots, plant seeds into thoroughly moist high-quality seed starting soil. Place seeds on the top of the soil and cover with 1/4″ of finely sifted soil.
• Once your lettuce has germinated and the first set of true leaves show, fertilize with an organic liquid fertilizer. When the plants are 3-4″ tall you can plant them out into the garden. If you are planting lettuce plants out during a warm spell or during the warm season, crop protection like shade cloth may be necessary.

Growing Lettuce

• Grow in full sun during the cooler part of the year. In warmer months, lettuce can take some shade. If the weather is particularly hot, you can use shade cloth to protect the crop.
• Lettuce requires good soil moisture. For Zones 9 and 10, this may mean hand watering daily or regular irrigation.
• Lettuce is easy to grow and does not suffer from many pest or disease issues. Plant with adequate spacing to ensure good airflow around the plants. This will help with aphids and whiteflies. If you do have pest issues, please see the UC IPM link below.

Harvesting Lettuce

• Lettuce can be harvested at any point that it is worth eating. Depending on the variety of lettuce being grown, you will either harvest the whole head or cut the lettuce 2″ above the ground and let it regrow. This is known as a cut and come again crop. There are at least five distinct types of lettuce.
  • Loose leaf lettuce is harvested as a cut and come again crop.
  • Crisp-head or iceberg lettuce grows a central head that is generally harvested whole.
  • Romaine lettuce grows a central head that is generally harvested whole.
  • Bib lettuce grows a central head that is generally harvested whole.

Growing Lettuce in Containers

• Lettuce is a great container crop. Make sure your container is at least 20″ deep. Keep in mind containers will dry out faster because they have more surface area and less soil to hold onto moisture. Mulch heavily on the top layer of soil in the pot to keep the soil from drying out or heating up too much.

Southern California Pro-tips

• In areas of Zones 9 and 10, lettuce can grow year round but will be less productive and tasty during the hot months.
• Mulch heavily around your plants to ensure the soil does not dry out or heat up too much.
• Protect lettuce during heat spells with shade cloth or row cover.

Companion Flowers/Crops

• Lettuce enjoys the company of flowers! Grow alyssum, nasturtium, and gaillardia around your lettuce plant both for beauty and to being beneficial insects.

Additional Learning Resources

• New to starting crops from seeds? Please watch our Seed Starting Presentation to learn the basics!
• Learn about growing all our crops on our YouTube page!
• Having pest issues? Check out in-depth information for pests that can be an issue for lettuce at the UC Integrated Pest Management site.