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Romaine lettuce    

Lactuca sativa var. longifolia

Romaine lettuce is part of the Lactuca (Lettuce) genus. Its scientific name is Lactuca sativa var. longifolia. The botanical name epithet for Romaine lettuce (sativa) means 'having been cultivated'.

Cos lettuce are easily recognisable as they are oval rather than round. The leaves are more robust than round lettuce and have a slightly bitter but pleasant taste.

Blooms appear in these approximate colours:   Unmellow Yellow. When mature, blooms are roughly 1.0 cm (that's 0.39 inches in imperial) in diameter. The mature flowers take a single form, with an approximate petal count of 4. Leaves appear approximately as a   Forest green (web) and   La Salle Green

It is a flowering edible vegetable that typically grows as an annual, which is defined as a plant that matures and completes its lifecycle over the course of a single year.

Romaine lettuce is known for growing to a height of approximately 7.8 inches (that's 20.0 cm in metric) with a stemless habit. This plant tends to bloom in late summer.

Consider Parris Island Cos, Little Gem, Red Romaine, Rouge d'Hiver and Little Caesar to grow as they are very popular with home gardeners.

Romaine lettuce is normally quite a low maintenance plant and is normally very easy to grow - great for beginner gardeners!

This plant info is provided by the myfolia gardener's wiki. All details about Romaine lettuce have been kindly provided by our members.

How to grow Romaine lettuce

  • Partial Sun

  • High

Use fleece to protect the growing seedlings from the worst of early season bad weather, and late season sun. Fleece also helps to keep pests at bay,
Harvest as soon as the leaves are useful, keeping the growing plants evenly moist to reduce bolting

Try to plant in a location that enjoys partial sun and remember to water often. Use Zone 4 - Zone 9 as your guideline for the appropriate climate for this plant. Romaine lettuce needs a loamy, potting mix and clay soil with a ph of 6.2 to 6.8 (weakly acidic soil). Keep in mind when planting that Romaine lettuce is thought of as tender, so it is imperative to wait until temperatures are mild before planting out of doors.

See our list of companion Plants for Romaine lettuce to see which plants you should plant in close proximity to encourage growth.

Growing Romaine lettuce from seed

Sow directly, and cover only lightly. Sow thinly to avoid having to thin too many seedlings. seeds need light to germinate
Sow a few seeds every two or three weeks, to prolong the crop

Ensure a distance of 11.7 inches (30.0 cm) between seeds when sowing - look to sow at a depth of approximately 0.23 inches (0.6 cm). Soil temperature should be kept higher than 5°C / 41°F to ensure good germination.

By our calculations*, you should look at sowing Romaine lettuce about 60 days before your last frost date .

Transplanting Romaine lettuce

Sow direct, lettuce do not transplant easily, thin seedlings to give the remaining plants room to grow.
Eat the thinnings

Ensure that temperatures are mild (minimum night temperatures should be around 12°C / 54°F) and all chance of frost has passed before planting out, as Romaine lettuce is a tender plant.

Harvesting Romaine lettuce

Harvest as soon as the leaves are a useful size, choosing the plants that will release the growing room for those remaining.
Pull carefully, so as not to damage the roots of the remaining plants

Seed Saving Romaine lettuce

Lettuce easily bolt and flower, and can be grown from seed collected into a paper bag.

Seed viability is three years.

How long does Romaine lettuce take to grow?

These estimates for how long Romaine lettuce takes to sprout, grow and harvest are from real observations from real gardeners, right around the world.

Start logging and journaling your observations to participate!

Days to Germination How long does it take Romaine lettuce to germinate?
7 days

Average 7 days | Min 1 days | Max 23 days (347)

Days to Transplant How long until I can plant out Romaine lettuce?
+ 31 days

Average 31 days | Min 2 days | Max 58 days (26)

Days to Maturity How long until Romaine lettuce is ready for harvest / bloom?
+ 50 days

Average 50 days | Min 4 days | Max 142 days (190)

Total Growing Days How long does it take to grow Romaine lettuce?
= 88 days

When should I plant Romaine lettuce?

Our when to plant Romaine lettuce estimates are relative to your last frost date.

Enter your frost dates and we'll calculate your sowing and planting dates for you!

When to sow The number of days to sow Romaine lettuce before or after your last frost date.
60 days before Last Frost Date

Romaine lettuce Etymology

Most dictionaries trace the word cos to the name of the Greek island of Cos, from which the lettuce was presumably introduced. Other authorities (Davidson) trace it to the Arabic word for lettuce.

Romaine lettuce Folklore & Trivia

Romaine lettuce is often used in the Passover Seder as a type of bitter herb, to symbolise the bitterness inflicted by the Egyptians whilst the Israelites were slaves in Egypt.

Other names for Romaine lettuce

Cos lettuce, Lattuga romana, Laitue romaine

Lactuca sativa longifolia

Misspellings: Romain, romain lettuce

Latest Romaine lettuce Reviews

  • Lovely red color! Lettuce was bitter, but I think I left it too late in the heat and did not soak.chill it well. I’ll try again next year.

    3 stars

    KiriBean about growing Lettuce, romaine 'Red Romaine' (OP) (H)
  • My first time growing this variety. Germination was erratic, plants were slow to take off, flavor a little stronger than I liked, but harvested plants were beautiful. Will try again this fall.

    4 stars

    mpsprengeler about growing Parris Island Romaine - 2nd sowing
  • I’ve grown this variety of Lettuce several times this year. I’m very pleased with them. They germinate very well & quickly & grow quite fast. I planted out my 3rd sowing 30th June on Gerry’s allotment

    4 stars

    Amarylis about growing Romaine lettuce 'Parris Island Cos'

See all Romaine lettuce reviews and experiences »


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