For hemp production, seeding 25-40lb an acre will give you the best results. Final plant population should be anywhere between 10-20 plants per square foot. Resources online vary wildly in suggested row spacing, and a range of spacing between 7”-30” has been suggested. The primary difference between varying row spacing will be the height of the seed head on the hemp plant. Wider row spacing will lead to seed heads lower on the plant, as the plants are given more room to develop. This may be an issue for combine harvesting, as the lower the seed head the lower the combine needs to be.
For fiber production, seeding 40lb-80lb an acre will give you the best results. Final plant population should range from 30-35 plants/sqft. Just like grain production, resources vary online as to what the ideal row spacing is. Fiber production should maximize the plants in any given square foot, so row spacing of 6”-10” should be ideal. For both fiber and grain production, a seed depth of 1/4″ to 3/4″ is a general range.
CBD production is where planting can get complicated. Unlike the two methods above, where the population of males and females in a field is not a significant issue, CBD fields require the sequestration and destruction of male plants before they can produce pollen. If a female cannabis plant is pollinated, it refocuses its energy from producing cannabinoids, the THC, CBD, and CBN, to producing seeds. Pollination of females will drastically reduce CBD levels in your crop. To solve this issue, many farmers will manually sex their plant after a few weeks of growing, identifying male plants and removing them before they mature. Row spacing for CBD production needs to be wide enough to walk between, so anywhere from 36”-50” will work well with 10lb-15lb of seeds an acre. Additionally, smaller farms have the option of growing cannabis from clones instead of seeds. Cloning enables farmers to standardize the genetics of a single harvest, as well as ensure that all plants being put in the field will be female.