I saw the following photo on my Facebook news feed:

I asked my friend who posted it for a source, and he gave me a link to a hemp manufacturer. I'm pretty sure it's not a reputable source. I'm interested to see if there is any independent study, patent, manufacturing process, etc, that shows this claim to be true.

  • 3
    I heard this claim in a Cypress Hill song.
    – Tom77
    May 14, 2013 at 15:44

2 Answers 2


This quote apparently comes from a 1916 USDA study on Hemp Hurds as a Paper-Making Material,

The most important point derived from this calculation is in regard to areas required for a sustained supply, which are in the ratio of 4 to 1. Every tract of 10,000 acres which is devoted to hemp raising year by year is equivalent to a sustained pulp-producing capacity of 40,500 acres of average pulp-wood lands. In other words, in order to secure additional raw material for the production of 25 tons of fiber per day there exists the possibility of utilizing the agricultural waste already produced on 10,000 acres of hemp lands instead of securing, holding, reforesting, and protecting 40,500 acres of pulp-wood land

Thus, this quote would have pre-dated modern manufacturing techniques for paper production as well as modern tree-farming techniques. This means that this is actually a difficult question to answer in part because tree farms and traditional farming techniques are completely different from each other and modern technology means that the techniques involved have likely changed greatly in the almost 100 years since the study was conducted.

To begin looking at things from a modern standpoint, tree farms typically thin a stand at 15 and 24 years with a final clear-cut harvest every 33 years (see slide 5 of 15). However, hemp can be harvested on an annual basis which puts it in line with traditional farm techniques1. This would imply that on a very simplistic level the hemp could come out ahead just because no thinning or harvest of a tree stand was done in a given year.

So to give a bit more of a fair comparison we are going to need to look at aggregate data and and look at the average yield per year. As with traditional farming different stands can result in different yields and in general harvesting sawlogs is more desirable than pulpwood (which is used to produce paper) since sawlogs are more valuable and therefore more profitable. This in turn means that stands tend to be managed with maximizing the amount of sawlogs produced.

The most commonly farmed trees for pulpwood appear to be Loblolly Pine, Acacia, and Eucalyptus with Eucalyptus being the most common. Based on my research, Loblolly Pine and Eucalyptus productions seem to be as follows:

The yields for hemp fiber3 on the other hand tend to be based more on historical data and tend to place the yields at 2 to 12.5 tons/acre/year with 5 tons/acre/year being the average on a good year. A modern report from a Kentucky farm put the yields at 2.8 to 6.1 metric tons/acre/year with other sites getting worse yields.

Thus, to return to the original claim, if we assume that only paper production is considered (i.e. fiber production in the case of hemp and wood pulp production in the case of trees) then the claim appears to be false with hemp yields only appearing comparable to Loblolly Pine per acre/year wood pulp yields although it is possible for hemp to out produce Loblolly Pine production when it is not grown for pulpwood.

However, if other trees are considered then well managed tree farms appear to greatly outproduce hemp farms in terms of per acre yields. The only way this claim is true is only if year-by-year data is examined due to the way tree farms are thinned and harvested due to the significant number of years of no production.

  1. For our purposes this is being defined as mechanically assisted farming with harvest being done at the ideal time to maximize yield.
  2. Green ton - 2,000 pounds of undried biomass material.
  3. This is also assuming the fiber is only used for paper production as opposed to other usage in clothing or rope production.
  4. Some useful timber volume-to-weight conversions.
  • I think you missed a step. After you harvest the wood you have to reduce the pulp. And then Yield the paper. The claim is not about the weight of much raw unprocessed source their is but rather the yeild of the finished product.
    – Chad
    May 23, 2013 at 18:06
  • @Chad - Indeed, but if the woodpulp yield is low then you aren't going to get more product out of it than you put into it in raw materials.
    – rjzii
    May 23, 2013 at 19:03
  • My point is you are comparing raw material quantity instead of yeild. The claim is that an acre of hemp will yield more paper than 4 acres of trees.
    – Chad
    May 23, 2013 at 19:29
  • @Chad - Sure, but finding the quantity of woodpulp needed to produce paper has actually been very had to answer as most of the answers are very "hand-wavy" since they tend to be in terms of "x tries to ream of paper" which introduces painful conversions. However, at the end of the day nothing I found implied that you can get more out than you put in (i.e. one ton of woodpulp produces one ton of paper) or at best the manufacturing loses were fairly minimal to the process.
    – rjzii
    May 23, 2013 at 19:43
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    If you included a source with that information then I think you have a good answer. You are just one step short right now imo
    – Chad
    May 24, 2013 at 12:49

No it doesn't.

There are several reasons why hemp is not used to make paper. Biggest one is that it's more expensive.

Hemp has never been used for commercial high-volume paper production due to its relatively high processing cost.

The cost of hemp pulp is approximately six times that of wood pulp, mostly because of the small size and outdated equipment of the few hemp processing plants in the Western world, and because hemp is harvested once a year (during August) and needs to be stored to feed the mill the whole year through.

While the wood products industry uses nearly 100% of the fiber from harvested trees, only about 25% of the dried hemp stem — the bark, called bast — contains the long, strong fibers desirable for paper production.

Hemp is only harvested once per year. And the hemp need to be stored for quite a while. Storing costs together with the fact that only a small part of the hemp can be used for paper, makes hemp not overly suitable for paper, economically.

Yields of hemp farming

Cultural requirements and production costs are quite similar to those of corn. Reported hemp yields range from 2.5 to 8.7 tons of dry stems per acre.3

Yields of wood

In the paper they use fast growing types of wood, and get a yearly yield of between 6 and 12 tons per year per acre.

Other paper

Production Rate per Acre: 6.9 green tons

Wood uses much higher efficiency converting wood to paper than hemp to paper. 1/4th vs close to 100%. Yields of wood per acre per year, is similar and sometimes more than the ones of hemp.

The picture is wrong, seeded forest is more efficient for paper than seeded hemp. Hemp is less efficient than wood, and doesn't give substantial better yield per acre per year, and is not as economically favorable as wood either.

All in all, wood and foresting is most efficient way to gain paper, per acre.

  • 3
    This is an interesting answer; it surprises me. But it needs better references. Rather than Wikipedia, why not go to the original sources? "Yields of wood" link is for wood pellets; are they used in paper-making? Where do you get the efficiencies from?
    – Oddthinking
    May 23, 2013 at 11:52
  • 1
    Also, hemp only being harvested once a year isn't really a point against it considering that commercial tree farming has an odd harvesting schedule, as per your source, 15, 24 and 33 years. Plus, does the four acres apply to clear cutting or selective harvesting techniques? Also, yields for wood seems to be highly variable, one of your citations says 2.0 tons/ac/year for pulpwood which is used for paper products which would be below the hemp yields. A good start but it needs a lot of work still.
    – rjzii
    May 23, 2013 at 12:00
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    okay I will give this answer a major work-over, and not use wikipedia for any part, and find more info about efficiency, and I will write down more details about the techniques used for harvesting the hemp and the wood, and which type of forest it is.
    – Wertilq
    May 23, 2013 at 12:22
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    @RobZ I think the point is that you can only harvest hemp in October, so you must do all of your harvesting then and then store it for the rest of the year. You can harvest trees at any time, as long as you rotate your harvest area, so you can have continuous production with minimal storage.
    – Ian
    May 23, 2013 at 15:48
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    @RobZ the answer lists that fact that "Hemp is only harvested once per year" as a disadvantage because it requires you to store it for the other 11 months. You commented "hemp only being harvested once a year isn't really a point against it considering that commercial tree farming has an odd harvesting schedule". What I'm saying is that it's not about the gap between harvests, its about how often you can harvest within a year. i.e with trees, as long as I've got enough of them that it takes me 15 years to get through all of them then I never have to stop. I can't harvest Hemp in winter/spring.
    – Ian
    May 23, 2013 at 16:13

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