UNITED STATES DEPARTMENT OF AGRICULTURE 
w BULLETIN No. 797 ^ 
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Contribution from the Bureau of Plant Industry 
WM. A. TAYLOR, Chief 
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Washington, D. C. 
November 22, 1919 
COMMERCIAL DUTCH-BULB CULTURE 
UNITED STATES. 
IN THE 
By David Griffiths, Agriculturist, Office of Horticultural and Poyivological 
Investigations, and H. E. Juenemann, Superintendent of the Bellmgham 
Plant-Introduction Field Station, Office of Foreign Seed and Plant Intro- 
duction. 
CONTENTS. 
Page. 
Bulb production in the United States- 1 
Soil adaptation 3 
Temperature, soil, and fertility re- 
quirements _ 4 
Number of bulbs, grown per acre 5 
Planting 6 
Depth of planting 9 
Treatment after flowering 10 
Roguing 10 
Harvesting the flowers 11 
Cultivation 11 
Harvesting the bulbs 13 
Storing and curing 14 
Cleaning 18 
Sizing 20 
Page. 
Advantages of sizing... 22 
Culling . 22 
Propagation 23 
Determination of flowering quality — 26 
Packing bulbs 28 
Shipping bulbs 28 
Bulb growing for pleasure 29 
Miscellaneous bulbs . 33 
Bulb pests 33 
The best varieties to plant 36 
Varieties of narcissi 37 
Varieties of tulips 41 
Varieties of hyacinths 46 
Bulb literature 47 
Definitions: 47 
BULB PRODUCTION IN THE UNITED STATES. 
The production of bulbs in the United States is in its infancy. 
In normal times the value of the bulbs used in this country is not 
far from $2,000,000 a year, while those actually produced here are 
scarcely worth $25,000 in any one year. 
This condition exists in spite of the fact that it has been known 
for generations that narcissus bulbs of perfect quality can be grown 
over a wide latitude and that tulips, although more exacting in their 
requirements, can also be produced successfully. Those best in- 
formed are just as sanguine about the production of hyacinth bulbs, 
126953— 19— Bull. 797 1 
