Grand Rapids TBR (Lettuce/looseleaf)
Latin Name: Lactuca sativa
Item #: 185C
45 days. This leaf lettuce is light green with crisp, well-bunched with very frilled leaves. Resistant to heat and tip burn.
LEAF LETTUCE for greenhouse & outdoor production
20,000 seeds per oz/28 g Field crops approx. 1.5 lbs/0.7 kg per acre; 500 ft/152 m per oz/28 g, 15 ft/5 m per pkt. Greenhouse crops .25 lb/113 g sown thinly provides enough seedlings for about an acre of transplants.
GREENHOUSE: Popular as an easily grown "cash crop" during short day winter months. Start sowing in flats about 30 days before you fall crop of tomatoes are ready to be cleared out of the house, or from Oct. 1 to Dec. 15th. Germinate @ 45 - 65°F/7 - 18°C. Higher soil temps (75°F/24°C) may delay germination. Cut early crops about Nov. 15th main crop around Feb.
EARLY SPRING OUTDOOR CROPS: Sow in flats or hot beds as above 1/4 in/6 mm. Deep Feb. 15th - March 15th for April transplanting outdoors. Grow transplants cool @ 40 - 45°F/4 - 7°C. Lower air temp. to near 32°F/0°C for a few days before transplanting into the field. Properly hardened plants can take temps. as low as 20°F/-7°C.
EARLY SUMMER CROPS: Can be sown every 10 days, from Mar. 20th till July, @ 3 seeds per in/25 mm. Thin when seedlings have developed about 2 or 3 leaves to 12 in/31 cm apart. Give them plenty of air, not too wet or too warm!
FERTILIZE: On sand soils @ 600 lbs/272 kg of 8 - 16 - 16 per acre. Side dress lightly with nitrogen about 3 weeks after transplanting or thinning. Control aphids every week from transplanting or seedling emergence. Aphids spread Aster Yellows.