COMMERCIAL DUTCH-BULB CULTURE. D 
factory for the production of Dutch bulbs as for the common staple 
crops usually grown there. 
The fertilizer requirement of bulbs is not sufficiently appreciated 
in this country. These stocks require heavy fertility to produce 
well and to maintain their size. We have sometimes thought that 
the better success with narcissus than with other bulbs is due to the 
fact that this group requires less fertility and is exceedingly im- 
patient of any soil loaded up with organic matter, even when well 
incorporated. This does not mean that the narcissus requires a 
lean soil, but that a heavily fertilized soil must not be in contact 
with the bulb. 
The practice of rotation by the bulb grower on the other side of 
the Atlantic is in this particular instructive. The formula of the 
rotation may be stated as follows: A heavy application of cow 
manure in winter, followed by a crop of potatoes dug early and 
followed by hyacinths one year, tulips the second year, and then nar- 
cissi. When the latter are left in for two years they commonly 
receive a top-dressing of manure the second year. The soil in which 
the narcissus is planted in this rotation has produced a crop of 
potatoes, one of hyacinths, and one of tulips. The application of a 
mulch of manure always works well with the narcissus, because the 
fertility is secured in the form of leachings. The relative fertility 
requirements of the bulbs are well exemplified in this rotation. 
NUMBER OF BULBS GROWN PER ACRE. 
A practical bulb grower will almost invariably shy at a question 
relating to the number of Dutch bulbs that can be grown on a 
definite area of ground, especially if the exactitude of the Dutch 
method be followed. The reason is apparent if we stop to reflect, 
Let us analyze an acre's planting on the Dutch plan. Allowing for 
one 10-foot roadway and the necessary waste on the sides, there is 
room on an acre for 48 beds with paths 1 foot wide. The length 
of these beds when the necessary crosswalks are taken out will be 
not more than 190 feet. If the rows are 6 inches apart 18,240 rows 
will be planted. Then if 7 bulbs are planted to the row, an acre will 
be fully occupied by 127,680 bulbs. On the other hand, if 50 bulblets 
to the row are planted it will take 912,000 to occupy the acre. In 
round numbers, therefore, the number grown on an acre will range 
from 125,000 to 900,000, a very wide variation. In practice, the 
grower may have 20 beds 50 feet long of one variety, and if he 
sizes his bulbs closely he will plant in those 20 beds, about one- forty- 
fifth of an acre, 7, 9, 11, 14, 21, 35, and 50 bulbs to the row. It is mani- 
festly very difficult to say how many bulbs can be grown on an 
acre. The matter is still more complicated by the constant fluctua- 
