A few herbicides are available for commercial production. For smaller plantings, hand weeding is recommended. Contact your county Cooperative Extension office for methods to control insects, weeds and diseases in larger plantings. Harvesting and Storage Spinach can be harvested until seedstalk formation. Spinach planted for early harvest is subject to bolting as daylight lengthens in late spring and early summer.
Spinach is harvested by cutting the stem below the head or rosette of leaves.
The crinkled leaves should be rinsed thoroughly in cold water to remove any grit soil particles. The leaves are then bunched. Remember that fall spinach is very hardy and not easily damaged by frosts. Harvest dark green, tender leaves that are 3 to 6 inches long. In the home garden, start by picking the outer leaves and then harvest the newer leaves as they reach the desired size.