Swanson’s Pure Culture Spawn 
Being one of the oldest mushroom growers in this countrry I have had 
the opportrunity of watching the development of this industrry from almost 
its very start. 
My growing experience taught me that many poor crops could be 
attributed to carelessly and poorly made spawn which induced me to make an 
intensive study of mushroom spawn and to learn how to produce it so that my 
crops would always be dependable. 
By keeping in close touch with the scientists who discovered this better 
method of producing spawn I was able to learn all about these new discoveries, 
to keep abreast with the times and to produce spawn of such quality that 
1 could be justly proud of. 
I had no intention at that time, of becoming a spawn manufacturer or of 
ever putting any of it on the market, but my friends and neighbors in the busi¬ 
ness, like myself, insisted on my making spawn for them. So we began to manu¬ 
facture back in 1896. At that time it was called brick spawn. Three-fourths of 
a pound to a square foot was then considered to be a good crop. Now our 
pure culture bottle spawn will average as much as one and one-half pounds, 
in many cases two and sometimes three pounds to the square foot. 
Our spawn is grown from spores taken from carefully selected mushrooms 
from highly productive beds. The laboratory where the spawn is planted is 
sanitary in every way and compares favorably with a hospital operating room 
in cleanliness, even the air is washed and filtered. This is practically insurance 
to the grower that the spawn is uncontaminated, vigorous because its growth 
is not interrupted or interferred with during its growing period and will pro¬ 
duce a wonderful crop if proper conditions are furnished for it to grow in. 
Further assurance is this, we experiment with new varieties of spawn every year at con¬ 
siderable expense to our concern in order to give the mushroom grower the finest variety 
obtainable. We take pride in our spawn and we assure the growers the most highly productive 
spawn on the market backed by thirty-eight years of experience in spawn making. 
As I said at the start I have v/atched the mushroom industry grow from its infancy and 
I realize that the time has arrived when the danger of over production is alarming, for this 
reason, unlike many other spawn manufacturers I am not furnishing a book of instructions, I 
am not interested in starting new growers in the business even though I might increase my 
spawn business by so doing. 
I am interested alone in the grower who has invested his savings in a plant and is devoting 
all his time to making a success of the mushroom business and‘it is my desire to be able at all 
times to supply such growers with good reliable spawn so that they may at least have the 
assurance of having a good paying crop. 
My policy therefore is to sell only to established growers who have their own method 
of producing mushrooms and whose success is due to their own practical experience coupled 
with good spawn. We aim to cooperate with our customers in this respect. 
My spawn has been on the market for many years and has been used by a great many 
experienced growers who know what to look for and expect in spawn and it has at all times 
proved its worth. This season we will again have some very good spawn to offer our 
customers. 
We have three varieties of white and one of cream, one bottle planting fifty square feet 
in beds. We can save our customers more than one-half of the express charges on the spawn 
if we break the bottles and ship only the spawn, if used immediately. In this pamphlet you will 
find a few testimonials from old reliable growers who have used my spawn for years. 
