Buttercrunch Untreated Lettuce

BUTTERHEAD LETTUCE fresh market

2 lb./1 kg per acre; about 20,000 seeds per oz./28 g

GREENHOUSE: A limited amount of the butterhead and boston types have been grown under glass during the winter months for mainly local gourmet sales. Since 1972 interest has increased among hydroponic greenhouse growers - sowing from Sept. 15th to Oct. 1st.; transplanting in peat pots or soil blocks a week later, then into the greenhouse in late Oct. or by Nov. 1st. Buttercrunch and Bibb types are sown later in the winter when days begin to lengthen. Space plants @ 8 x 8 in./20 x 20 cm with a day air temp. of 60°F/16°C minimum and 40°F/4°C nights. Maintain a C02 level of 1200 PPM.

DIRECT SOWING: Sow seed as thin as possible @ 3 seeds per in./25 mm from Apr. 1st to July 1st in several sowings (10 days apart), for a continuous supply throughout the summer. Plant seed 1/4 in./6 mm deep, cover lightly with fine soil and firm. Thin seedlings when they have 3 or 4 leaves, to 8 in./20 cm apart. Space rows 18 in./46 cm apart. Harvest alternate heads. Fertilize lightly three weeks after transplanting or thinning, and every 10 days thereafter throughout the season. Keep plants well watered during dry periods. Control aphids - they spread diseases.