10 
BULLETIN 
U. S. DEPARTMENT OE AGBICULTUBE. 
which has more humus iu its composition. Likewise, the intended 
application of litter later in the season will influence the depth of 
planting. 
In fact, the depth at which bulbs are set in commercial and decora- 
tive plantings is far from what occurs in nature, and they thrive at 
many varying depths. The point is emphasized in the case of many 
tulips which drop down 2 to 4 inches below the 4-inch level at which 
they are planted. It is not uncommon with us to have crocuses and 
tulips which are missed in the field come up the next season from a 
depth of 10 inches and flower perfectly. Indeed, there are indications 
that a great deal is still to be learned about the depth of planting, 
especially of tulips. There are accounts of tulips in Italy which have 
flowered perfectly for 12 to 15 years when planted a foot deep. There 
appears to be a corre- 
lation between deep 
planting and the per- 
manent performance of 
tulips which are not 
shifted annually. 
TREATMENT AFTER 
FLOWERING. 
Little attention need 
be given to narcissus 
bulbs after flowering 
except that for the best 
results they should be 
kept free of weeds, like 
all other crops. With 
hyacinths and tulips, however, the matter is different. Here, it is 
necessary to remove the flowers, for the reason that there is an 
abundant seed production, which if allowed to develop would be at 
the expense of bulb growth. Again, with tulips it is imperative 
under certain conditions that no flower parts be allowed to fall upon 
the beds. Under seacoast conditions of humid atmosphere and heavy 
precipitation during the flowering season and immediately thereafter, 
the presence of fallen petals is very conducive to the development of 
the fungus Botrytis, the cause of the fire disease. It is therefore nec- 
essary in such situations to remove the flowers (fig. 5) before the 
petals fall. In varieties of narcissus which produce seed in abund- 
ance the removal of the flowers is, of course, advantageous. 
ROGUING. 
In the process of handling bulbs, mixtures are certain to take place 
to a greater or less degree. The laborer may be careless, or a bulb 
Fig. 5. — Removing the flowers before the petals fall in 
order to prevent seed production and the spread of the 
fire disease. 
