The tobacco was hoed for the first time about eight to ten days after planting, or to use a common expression, when the plants had "taken root." The tobacco was usually hoed once each week or as often as was deemed necessary to keep the soil "loose" and the weeds down. When the plants were about knee high they were "hilled up," as the Indian had done his corn, or the Englishman his cabbage, and considered "laid by." Frequently some of the plants died or were cut off by an earthworm; these vacant hills were usually replanted during the month of June, except when prohibited by law. This restriction was an attempt to reduce the amount of inferior tobacco at harvest time. Around 1800, plows were still rarely used in new grounds, but they appear to have been rather common in the old fields. George Washington used the plow to lay off his tobacco rows into three-foot squares, the hills were then made directly on the cross so that in the early stages of its growth the tobacco could be cultivated with the plow each way. The plow lightened the burden of cultivation by requiring less hoe work. When the plant began to bloom, usually six or seven weeks after planting, the plant was topped; that is, the top of the plant was pinched out with the thumb and finger nails. The number of leaves left on the plant depended largely upon the fertility of the soil. In the early days of the colony, planters left twenty-five or thirty leaves on a plant, by 1671 the number had been reduced to twelve or sixteen in very rich soil. Throughout the seventeenth century the General Assembly, in an attempt to reduce production, occasionally limited the number of leaves that could be left on a plant after topping. After around 1700, from five to nine leaves were left on the plant, depending on the strength of the soil.