Several lettuce varieties are suited to Quebec’s climate. Some of the most popular are romaine, iceberg, oak leaf, and Boston lettuce.

Lettuce can be sown indoors or directly in the ground. To start it indoors, sow the seeds four to six weeks before the expected last frost (mid-May in Quebec). For direct sowing outdoors, wait until nighttime temperatures have stabilized at around 4°C.

Starting Seeds Indoors:

Use a light, well-drained seed-starting mix. Fill pots or seedling trays with the mix. Sow two to three seeds per pot about 0.5 cm deep. Water lightly and place the pots in a warm location (20–22°C) with plenty of light. The seeds should germinate in seven to ten days. Thin them to keep only the strongest seedling in each pot.

Transplanting Outdoors:

Wait until the seedlings have at least three to four true leaves. Gradually acclimate them to outdoor conditions over one week by taking them outside during the day and bringing them back in at night. Transplant them into the ground, leaving 20–30 cm between each plant and each row.

Planting Outdoors:

Prepare the soil by loosening it and adding compost or other organic matter. Sow the seeds directly in the ground, spacing the rows 30 cm apart and the plants 20 cm apart. Cover the seeds with 0.5 cm of soil and water lightly.

Water regularly to keep the soil moist but not waterlogged. Avoid wetting the leaves to help prevent disease.

Mulch around the plants to retain soil moisture and limit weed growth.

Thin the seedlings if necessary to give them enough room to grow.

Lettuce is generally ready to harvest 60–80 days after sowing, depending on the variety.

For a gradual harvest, pick the largest, outermost leaves first while allowing the younger leaves to continue growing.

If you want to harvest the whole head, carefully cut the base of the plant a few centimetres above the soil. This can encourage new leaves to grow for a possible second harvest.