COMMEKCIAL DUTCH-BULB CULTURE. 
9 
covered either with the plow or with a winged cultivator which 
throws the dirt from the back furrow in either direction on the beds 
of set bulbs. 
In the South Atlantic region bulbs are planted usually in 15-inch 
rows, the rows being opened with a 1 -shovel winged cultivator. The 
bulbs are then set 2 or 3 inches apart and then covered by running a 
harrow over the ground. It is said that during the past two or three 
years an innovation has been introduced in some places in the Nether- 
lands where a special 10-inch moldboard plow, having a triangular 
extension downward and outward, makes a depression the entire 
length of the furrow slice. The bulbs are set in this and the next 
bout covers the first row and opens another 10 inches from it. 
DEPTH OF PLANTING. 
About the first question asked by the novice relates to the depth of 
setting bulbs used in decorative planting. English writers dwell on 
SURFACE OF GROUND 
Fig. 4. — Sketch showing the proper depth to plant various kinds of bulbs : A, Crocus ; 
B, snowdrop ; C, iris ; D, gladiolus ; E, tulip ; F, narcissus ; G, hyacinth ; H, lily. 
this point and are explicit in their instructions. The accompanying 
diagram 1 (fig. 4) is a useful guide in planting bulbs for decoration. 
A common rule is to set the bulbs at a depth 2-J times their diameter. 
Such a rule, while useful to the novice, will be little followed by one 
having experience with bulbs. He will know by intuition and will 
vary the depth with varying conditions. He will set his bulbs deeper 
in light than in heavy soil and in exposed than protected places. He 
will also set bulbs deeper in ground which heaves badly than in soil 
1 Adapted from Wight's Pictorial Practical Bulb Growing. 
126953°— 19 2 
