Great Lakes 659

Lettuce

70d to harvest

Cool, crisp perfection begins with Great Lakes 659—an elegant crisphead forming tight, uniform heads that feel satisfyingly dense and snap with a clean, watery crunch. The flavor is fresh and gently sweet, with a pale, buttery interior and crisp outer leaves that hold their structure beautifully in the garden. Grow it for classic crisphead salads and refreshing wedges, and enjoy its dependable, market-ready texture at maturity in about 70 days.

Crop Dates

Growing note: In frost-free Zone 10b, grow this cool-season crop during the cooler dry season (October–February).

Milestone	Date
Start Indoors	—
Climate	Frost-Free Climate
Transplant / Sow Outdoors	Oct 1st
Harvest Begins	Dec 10th
Harvest Ends	Feb 28th

Crop Details

Trait	Value
Days to Maturity	70
Sun Requirements	Full Sun
Growth Habit	Rosette
Support Needed	None
Planting Depth	Surface
Germination Temp (°F)	55
Min Soil Temp (°F)	40
Min Night Temp (°F)	32
Harden Off (days)	5

Frequently Asked Questions

What pest or disease is most common on Lactuca sativa (leaf lettuce), and how can I control it?

Lettuce commonly gets downy mildew and aphids (often together on cool, humid days). For downy mildew, remove affected leaves, improve airflow, and avoid wetting the foliage; if it keeps spreading, use a labeled fungicide suitable for lettuce. For aphids, blast plants with a strong water spray and then spot-treat with insecticidal soap if colonies persist—don’t wait because aphids multiply quickly on lettuce.

How often should I water Lactuca sativa during peak growth, and what soil moisture level should I maintain?

During the main growth phase (after seedlings establish), keep the soil evenly moist but not soggy—aim for consistently damp soil 1–2 in (2–5 cm) deep. Water deeply about 2–3 times per week in typical home gardens, increasing to every 1–2 days during hot, windy weather. If leaves taste bitter or plants look stressed, it usually means the soil has dried too far between waterings.

How do I tell when Lactuca sativa 'Great Lakes 659' is ready to harvest?

Harvest when heads (or leaf clusters, depending on how you’re growing it) reach the expected mature size and the leaves feel firm rather than limp. Look for maturity around 70 days from sowing and harvest on a cool morning before heat makes the leaves tougher. If you see the center starting to bolt (rapid vertical growth and flower stem forming), harvest immediately to get the best flavor.