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How Many Seeds or Clones Do I Need?

In the pursuit of cultivating industrial hemp, a farmer will eventually need to answer one very important question – just how many seeds do I need to purchase? To answer this with any degree of accuracy, though, a farmer must first ask themselves a series of questions, including: 1) How many acres do I want to grow? 2) What do I want my plant and row spacing to look like? 3) Do I want to invest in female-only plants or mixed-gender?

The average seed is aprox. 3mm in diameter. The plant may eventually grow to 4 feet wide x up to 8 feet tall.

While there are dozens of methodologies, varieties and end-uses for industrial hemp, this article will focus on growing the plant outdoors utilizing raised beds (berms) with a harvested product intended for the CBD industry.

Short Answer:

4′ x 4′ spacing = 2,722 seeds/acre
4′ x 6′  spacing = 1,815 seeds/acre
5% additional when purchasing seeds

Three Primary Questions To Ask:
When growing industrial hemp outdoors, there are three primary questions a farmer must ask themselves to determine the number of seeds to purchase.

1) How many acres do I want to grow?

If the farmer is new to industrial hemp cultivation, but has experience farming with traditional crops, we recommend starting on no more than 40 acres with 20 acres being the optimal size. Industrial hemp farming is still in its infancy and while hemp-farming technology is rapidly catching up – it is still a very manual, labor driven crop. Growing on too much acreage has the potential to become a logistical nightmare.

2) What do I want my plant and row spacing to look like?

Photo by Debbie Roos. Source: NC State

The primary method and spacing for industrial hemp cultivation utilizes raised beds(berms) with 4 foot x 4 foot spacing between plants and rows. This method optimizes the density of plants per acre but does not leave considerable room between rows for harvesting equipment, tractors, or ATV/UTVs. Some farmers will choose to implement 4 foot spacing between plants and 6 foot spacing between rows in order to give an ATV, UTV or other farm equipment ample room to maneuver.

3) Do I want all female plants or male and female?

The goal of high-yield industrial hemp production is to maximize cannabinoid content in the plants being grown. Pricing of harvested crops is typically calculated as a dollar amount per percentage of cannabinoids per dried-pound of plant material. The more cannabinoids – the more a farmer will receive for his/her crop.

Hemp is dioecious plant – having both male and female genders and the majority of cannabinoid content is isolated to the female flower/floral material. Therefore, to maximize yield from the plants, it’s important to have as many females on the farmer’s land as possible. 

Male (left) vs. Female (right)

When not pollinated, female plants will grow dramatically in size and focus their energy on cannabinoid production in their flowers. Because they are an annual plant, their natural goal is to continue growing in a fashion that gives them a higher chance of being pollinated – hence the larger flowers.  Once pollinated, the plants redirect their energy to seed production – which contains zero cannabinoid content and degrades the overall crop yield. Here arises a crossroad for the farmer – do I want to invest in all female plants? If yes, they’ll be looking to purchase industrial hemp “clones” – small, rooted plants taken as cuttings from existing females that can be transplanted into their field by hand or via a transplanter. Current industry pricing of clones is primarily in the range of $4/clone to $12/clone.

Pros of Clones: Guaranteed female plants. No germination or propagation needed. Lower initial labor investment.
Cons of Clones: Cost. Learning curve.

If the cost of purchasing clones is not economical, or the farmer is in their first two years of hemp production, we recommend purchasing mixed-gender seeds. When purchasing mixed-gender seeds, a farmer’s field will most commonly be 50% male and 50% female. Males, in the late stages of their life-cycle, will release pollen into the wind and degrade the cannabinoid yield of a farmer’s female plants. To overcome this, mid-season, the farmer will need to inspect their field and cull the males by removing them at the stalk with a pair of hand-operated or machine-assisted loppers. Current industry pricing of seeds is typically $0.60/seed to $2.00/seed.

Pros of Seeds: Affordability. Lower financial risk. Deeper education of the plant.
Cons of Seeds: Higher labor investment. Males should be culled.

How many total seeds are needed?

In total, just how many seeds are needed? There are 43,560 square feet per acre and 4′ x 4′ spacing is equivalent to 16 square feet. 43,650 divided by 16 = 2,722 plants per acre. 4′ x 6′ spacing is equivalent to 24 square feet which equals 1,815 plants per acre.

Next, take the farmer’s desired acreage and multiple it by the number of plants per acre calculated from above.

4′ x 4′ spacing = 2,722 plants x 40 acres = 108,880 seeds or clones.
4′ x 6′ spacing = 1,815 plants x 40 acres = 76,600 seeds or clones.

If ordering seeds, we recommend ordering 5% more seeds than the farmer is expecting to plant. This should be an ample number of seeds to cover any issues during germination that may arise.

I Have More Questions!

If you have any questions please feel free to email us at [email protected] or fill out our form located on our contact page.