UNITED STATES DEPARTMENT OP AGRICULTURE 
BULLETIN No. 797 
Contribution from the Bureau of Plant Industry / 
WM. A. TAYLOR, Chief " 
Washington, D. C. 
November 22, 1919 
COMMERCIAL DUTCH-BULB CULTURE 
IN THE UNITED STATES 
By 
DAVID GRIFFITHS, Agriculturist, Office of Horticultural and 
Pomological Investigations, and H. E. JUENEMANN, Super- 
intendent of the Bellingham Plant-Introduction Field Station 
Office of Foreign Seed and Plant Introduction 
CONTENTS 
Page 
Bulb Production in the United States . . 1 
Soil Adaptation 3 
Temperature, Soil, and Fertility Require- 
ments 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 
WASHINGTON 
GOVERNMENT PRINTING OFFICE 
1919 
