Lettuce – types and how to grow them year-round

Lettuce -- Types and How to Grow It Year-Round

Lettuce is one of the most frequently grown leafy vegetables in Czech gardens and balconies. It is undemanding, grows quickly, and with proper planning you can harvest it practically throughout the year. In this guide, we will introduce the main types of lettuce, their characteristics and benefits, and advise you on how to plan sowing so you have fresh lettuce on your table from spring through winter.

You can find lettuce seeds and other leafy vegetables in the leafy vegetable seeds category.

Main Types of Lettuce

Butterhead Lettuce (Lactuca sativa var. capitata)

The most traditional type of lettuce in Czech cuisine. Forms compact heads with crisp, light green leaves. The taste is mild, slightly sweet with a subtle mustard note.

Popular varieties:
- Maraton -- large, firm heads, reliable resistance to bolting
- Pražan -- classic Czech variety with quick growth suitable for early sowing
- Ledový (Iceberg) -- crispy, firmer leaves with longer shelf life after harvest

Growing: Sow from March to August, harvest in 50--70 days. Prefers mild temperatures (15--20 °C). During prolonged heat, it quickly enters the generative phase and bolts.

Romaine Lettuce (Lactuca sativa var. longifolia)

Upright, oblong-shaped heads with firmer, crispy leaves. The basic ingredient for Caesar salad and an increasingly popular alternative to butterhead types. Compared to butterhead lettuce, it tolerates higher temperatures better.

Popular varieties:
- Little Gem -- compact miniature variety ideal for growing in containers on the balcony
- Parris Island Cos -- classic full-size romaine lettuce with good heat tolerance
- Rouge d'Hiver -- reddish-brown winter lettuce suitable for cooler periods

Growing: Sow from March to September, harvest in 60--75 days. Due to its firmer leaf structure, it tolerates higher temperatures substantially better than butterhead types.

Loose Leaf Lettuce

Does not form a head -- leaves are gradually picked from the outside of the plant while the center continues to grow. The advantage is a significantly longer harvest period from a single plant.

Popular varieties:
- Lollo Rossa -- curly red leaves with decorative appearance, also suitable as an ornamental plant
- Lollo Bionda -- green version of Lollo with delicate flavor and quick growth
- Dubáček (Oak Leaf) -- leaves shaped like oak leaves, very delicate flavor
- Salad Bowl -- large, rippled leaves, high yield, tolerates partial shade

Growing: Sow from March to September. First leaves are harvest-ready in 30--40 days. One plant produces leaves for 4--8 weeks.

Arugula (Eruca sativa)

Piquant, nutty-spicy flavor that has ranked it among the most popular salad greens in recent years. Botanically not a lettuce (it is related to brassicas), but is grown and used in the same way.

Types:
- Cultivated arugula (Eruca sativa) -- broader leaves, milder flavor, significantly faster growth
- Wild arugula (Diplotaxis tenuifolia) -- narrower leaves, more intense and lasting flavor, perennial plant more resistant to heat

Growing: Sow from March to September, harvest in 25--35 days. In heat it flowers quickly and becomes bitter -- sow in semi-shade or in shorter intervals and smaller batches.

Corn Salad (Valerianella locusta)

Delicate, nutty-aromatic salad with small ground rosettes of leaves. Exceptional for its ability to tolerate cold -- it is an ideal choice for fall and winter growing when other lettuces have long matured.

Popular varieties:
- Vit -- quick growth, large full rosettes
- Elan -- increased resistance to mold, suitable for humid conditions
- D'Etampes -- French variety with regular, full rosettes and excellent flavor

Growing: Sow from August to September for fall and winter harvest, or from February to March for spring harvest. Germinates reliably even at low temperatures from 5 °C.

Year-Round Sowing Schedule

The key to continuous lettuce harvest is regular sowing at 2--3 week intervals. Below you will find a plan for each season.

Spring (March--May)

• March: Sow under film or in a seedbed -- butterhead lettuce, romaine, loose leaf. Corn salad from fall sowing is ready for harvest in this period.
• April: First sowing in open ground after stable warming. Arugula, loose leaf lettuce. Continue interval sowing every 2--3 weeks.
• May: Full operation of all types. Watch for late frosts -- until May 15th, the risk of frost is still real.

Summer (June--August)

• June--July: Choose varieties resistant to bolting -- Batavia, romaine lettuce or loose leaf types. Placing in partial shade or sowing between taller vegetables extends the harvest period. Sow arugula more frequently and in smaller batches.
• August: Start fall sowing of corn salad. Last suitable time to sow butterhead lettuces intended for fall harvest.

Fall (September--November)

• September: Last sowing of arugula and loose leaf lettuce, ideally under film or in a protected bed. Sow corn salad by mid-month at the latest.
• October--November: Harvest the last lettuces from open ground. Under film or in a greenhouse, continue harvesting corn salad, spinach, and winter arugula.

Winter (December--February)

• In a greenhouse or film tunnel: Corn salad, winter lettuce Rouge d'Hiver, spinach, and winter arugula easily survive even in an unheated space.
• On a windowsill: Microgreens and sprouts -- a quick and productive source of fresh vegetables in winter months, harvest in 7--14 days.
• February: Start pre-growing butterhead lettuce for spring transplanting.

Practical Tips for Successful Growing

Soil and Fertilizing

Lettuces prefer humus-rich, moderately moist soil with pH 6.0--7.0. Before sowing, work ripened compost into the soil. Lettuces are weak to moderate feeders -- usually a reserve supply of compost without additional fertilizing during the growing season is sufficient. The exception is lettuce grown in containers, where we recommend fertilizing once every 2--3 weeks with a weak nitrogen fertilizer solution.

Watering

Regular watering is key. Lettuces have a shallow root system and suffer very quickly from drought. Water in the morning so the leaves dry during the day and reduce the risk of fungal diseases. Drip irrigation or mulching with organic material helps maintain even moisture while also suppressing weeds.

Pest Protection

• Slugs: The greatest enemy of lettuces. Use mechanical barriers (copper tape, circles of sawdust or gravel), beer traps, or biological preparations based on ferric phosphate, which is safe for pets and beneficial insects.
• Aphids: Spray with a strong stream of water or potassium soap solution; in case of heavy infestation, repeat after 3--4 days.
• Mold: Ensure good air circulation, don't sow too densely, and avoid evening watering.

Harvest

Harvest butterhead lettuces when the head reaches full size and is still firm -- overripe heads lose flavor and texture. Harvest loose leaf lettuce gradually by picking outer leaves; inner leaves continue to grow and extend the harvest period. Cut arugula and corn salad with scissors about 2 cm above the ground -- they will regrow in 2--3 weeks.

You can find other leafy vegetable seeds including spinach, chard, and Asian lettuces in the leafy vegetable seeds category.

FAQ -- Frequently Asked Questions

Why is my lettuce bolting into flower?

The main cause is heat (above 25 °C) combined with long days. Bolting is also accelerated by drought and lack of nutrients. Prevention: choose varieties marked as "bolting-resistant" (e.g., Batavia or romaine types), grow in partial shade during summer months, and maintain regular watering.

Can I grow lettuce in an apartment on a windowsill?

Yes, but you need to account for certain limitations. On a north-facing window there will be insufficient light. On a south- or east-facing window, conditions are significantly better. We recommend loose leaf varieties and arugula, which don't require head formation and are satisfied with less space. An excellent alternative is microgreens -- sprouts of lettuce and other plants harvested in 7--14 days, rich in nutrients.

How long does harvested lettuce stay fresh?

Butterhead lettuce lasts 3--5 days in the refrigerator wrapped in a damp cloth or stored in a perforated bag. Loose leaf lettuce and arugula 2--3 days. Corn salad 3--4 days. For maximum freshness, harvest in the morning when leaves are fully turgid and full of moisture, and immediately store in the cold.

Which lettuces best tolerate Czech winters?

Corn salad is the clear winner -- it survives frosts down to --15 °C under a snow cover without any protection. Other hardy varieties are winter romaine lettuce Rouge d'Hiver, winter spinach, and endive. In heated or at least protected greenhouses, most varieties can be successfully grown all winter long.