Early planting is not recommended for any of the varieties of field beans. The bbjections are: (1) There is danger of the seeds rotting before germinating; (2) if the plants appear too soon frost may catch them; (3) early plantings are more likely to rust than later plantings; (4) cold, wet weather may stunt the plants, cause an uneven start and consequently a lack of uniform maturity. It is always better to wait until the ground is thoroughly warm and when there is little danger of damaging weather conditions. The kidney group may be planted the earliest, followed by the marrows and then the pea varieties. In New York the kidneys may be planted the latter part of May, and the pea varieties from June 5 to 20.
Spacing distances between rows range from 24 to 34 inches, 28 being most popular. Some investigators believe the largest yields are obtained when the beans are 4 to 6 inches apart, while the usual distance is from 2 to 4.
The depth of planting should be regulated by the character of the soil; in heavy soils 1 1/2 inches is ample, while 2 to 3 is not too deep in the lighter soils. For planting, one-half bushel of the smaller beans an acre is the most common allowance, while some farmers prefer three-fourths of a bushel; from 4 to 6 pecks of the kidney varieties are used an acre.
Field beans are usually planted with grain drills. Either 9 or 11 tube drills may be employed. The operation is explained by the Michigan Station (Michigan Station Bulletin 259, p. 91) as follows: "One of the best machines for planting beans is the ordinary 11-drill grain seeder with 7-inch spaces between the tubes. Stop up all the tubes except the 2d, 6th and 10th and let the drill wheel follow in its own outer wheel mark instead of in the last drill mark, as in sowing grain. This will plant three rows at a time, 28 inches apart, which is about the proper distance. In planting the larger varieties of kidney beans, a bean attachment or special bean drill should be used. Some makes of grain drills have attachments for planting beans." Press wheels on the tubes are valuable to secure a uniform depth of covering and an even stand. Field beans are sometimes grown in hills, but drills are favorable to larger yields.