2 CIRCULAR 3 81, U. S. DEPARTMENT OF AGRICULTURE 



from year to year. This is clone principally to avoid mixing the 

 planted varieties with volunteer growth, but sometimes to benefit 

 by better soil conditions. In shifting the planting stock, the experi- 

 enced bulb grower, who prepares his ground in accordance with ac- 

 cepted precultural methods and proper fertilization, also takes into 

 account the injurious rodents that may infest either the tract itself or 

 the adjoining waste lands. Such growers do not need to be urged to 

 clean up the lands as completely as 1 possible in advance, rather than 

 to subject valuable bulbs to the menace of hungry rodents, the rela- 

 tions of which to their environment have already been disturbed to 

 some extent by cultivation. This freeing the lands of injurious mam- 

 mals should start at least a year before the bulbs are to be planted, 

 and earlier if possible. 



RELATIVE PALATABILITY OF THE COMMON BULBS 



The palatability of the bulbs more commonly grown has been 

 tested in the laboratory both by human taste and by repeated experi- 

 ments with the smaller rodents in captivity. Not only have the 

 likes and dislikes of the animals experimented with corresponded 

 closely with those of the human palate, but later investigations in 

 the field have borne out the conclusions reached in the laboratory. 



In general, bulbs of tulips, Dutch and Spanish irises, and crocuses 

 (corms) are found to be readily acceptable both to rodents and to 

 the introduced ring-necked pheasant. 1 Hyacinth, freesia, lily, and 

 grape hyacinth (MuscaH) bulbs are perhaps less relished by rodents 

 but are often seriously damaged locally, and only narcissus seems 

 to be practically immune to their attack. The corms of gladiolus 

 apparently are not sought after by most rodents, but sometimes the 

 smaller-sized planting stock is stored by pocket gophers in consider- 

 able quantit}^. These corms have a bitter, pungent taste but are not 

 more unpalatable to man than are the roots of certain wild plants 

 to be found in the pocket gopher's stores. Bulbs of ixia, sparaxis, 

 and scilla, which are not so extensively grown, may be classed with 

 those of indifferent but not unpleasant flavor. 



Some bulbs are distasteful and sometimes have poisonous qualities. 

 Dutch authorities report the poisoning of pigs and calves by nar- 

 cissus bulbs, fed them at times when there was a surplus of this 

 product and a scarcity of other forage. In Pammel's manual of 

 poisonous plants it is stated that many members of the amaryllis 

 family have acrid properties, that some of them are poisonous, 

 and that poet's narcissus produces intense gastroenteritis. In a 

 catalog of the poisonous plants of all countries are listed several 

 species of narcissus and hyacinth. 



MAMMAL PESTS OF BULBS 



The chief smaller mammals the activities of which interfere with 

 bulb growing in the Pacific Coast States are moles, mice, rats, pocket 

 gophers, and rabbits. 



1 Sometimes ring-necked pheasants also completely demolish small tulip, iris, and 

 crocus plantings in garden or park by prodding into the earth with the beak to tear 

 out the bulbs and tender underground parts of the stems for food. Control measures 

 should be undertaken only after consulting local game wardens, as these birds are 

 protected by law, and therefore as a rule should be frigbtened but not destroyed. 



