Photo by Eunice (CC BY-SA 2.0).

Scientific Name: Lactuca sativa

Common Name: Lettuce 'Great Lakes', Crisphead Lettuce 'Great Lakes', Iceberg Lettuce 'Great Lakes'

Family: Asteraceae (Daisy)

Etymology

Lactuca: Milk (Reference To Sap)
sativa: Cultivated

Origin

Lettuce is of Indian origin.  The heirloom variety 'Great Lakes' was bred in 1941 in the USA and was notable as it was the first true iceberg-type lettuce with a denser head than any European crisphead-type lettuces bred prior to it.

Description

Great lakes is a heirloom iceberg type lettuce that produces large, crinkled leaves which form a dense head in the centre.  This is a popular and easy to grow variety that is slow to bolt to seed.

Uses

Great lakes lettuce has a mild flavour which makes it an excellent variety for shredding and adding to wraps, burgers and sandwiches.

Germination

Sow from March through to September in subtropical areas, all year round in temperate regions or from September to February in cold regions.  Lettuce seeds will not germinate when soil temperatures exceed 30 degrees Celsius and do best when soil temperatures remain between 15 and 20 degrees Celsius.  Space plants 30cm apart.  Lettuce seeds require light to germinate so should not be planted any deeper than 4mm, firm down well and keep well watered to avoid the germinating seeds drying out.

Cultivation

Great lakes heirloom lettuce takes 12 to 13 weeks from sowing until harvest.  Not suitable for growing in tropical regions.  Heavy feeder.  Plant under shade if growing conditions will be hot.