UNITED STATES DEPARTMENT OF AGRICULTURE 



,„^ BULLETIN No. 797 i^ 



J, jyRS-* Contribution from the Bureau of Plant Industry 



WM. A. TAYLOR, Chief 



jrw^°^V«^ 



Washington, D. C. 



November 22. 1919 



COMMERCIAL DUTCH-BULB CULTURE 

 UNITED STATES. 



IN THE 



By David Griffiths, Agriculturist, Office of Horticultural and Pomologlcal 

 Investigations, and H. E. Jtjenemann, Superintendent of the Bellinghatn 

 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 



Balb 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 



