The effects of temperature and planting dates on germination, emergence, growth, vegetative development, and time to flowering and maturity of the pods of pigeon pea were evaluated. Growth chamber studies were conducted to determine the effects of 12.5°, 15°, and 20° C on the germination of pigeon pea cultivar 2B-Bushy. Germination percentage was low (1.0 and 2.0%) at 15° and 12.5° C, respectively. At 17.5°, germination increased to 18% (average) and required 4 to 9 days. At 20° C, germination was 48° (average) and required 2 to 5 days. The vigor of the seed lot appeared to be low. Replicated field studies were conducted with large plant populations to determine the effect of planting date on emergence, growth, flowering and maturity of the pods of the commercial cultivar 2B-Bushy and two lines (PR2 7/13 and PR2 7/16) for early maturity in New Jersey (40° N fat,). Pigeon peas seeded May 19 emerged in 12 days at a mean soil temperature of 19° C at 2.5-crn depth. At later planting dates (2 June, 16 June, 1 July and 14 July) pigeon peas emerged in 6 or 7 days. Plant height and height to the first branch at flowering decreased in all three genotypes at the later planting dates. Pigeon peas planted at all sowing dates were tall but could be harvested with mechanical equipment. Planting date had a significant effect on the earliness of flowering and the percentage of plants that flowered. All plants of the PR2 selections flowered at all planting dates. The 2B-Bushy cultivar flowered only the first three planting dates; and not all the plants flowered. The 2B-Bushy flowered in the upper one-third of the plant, whereas the PR2 lines flowered in the upper two thirds. None of the plants of the 2B-Bushy genotype produced pods by the termination of the experiment, 15 October, just before frost. The PR2 lines seeded May 19 and June 2 produced 12% of the plants with mature green pods, and 6% of the plants with some dry pods, respectively, by 15 October. About 3% of these PR2 plants had 90% of their pods dry by 15 October. Thus, the PR2 lines were highly variable for maturity at 40° N lat. Therefore, pigeon peas could be selected for adaptation to this location and even more northerly areas.