RODENTS AND MOLES AS PESTS IN BULB PLANTINGS 9 



crop in the ground, lily plants need watching for signs of rodent 

 damage at seasons when cultivation is not in progress. 



PREVENTIVE MEASURES 



Efforts made to eliminate damage by burrowing animal pests may 

 include the selection of a location for bulb growing that is free from 

 them, the exclusion of pests from the field, and the control of those 

 present. If preventive measures are possible, so much the better, as 

 they forestall all injury; but control is usually the most practicable. 

 One of the difficulties is the fact that the conditions of soil and 

 climate essential to successful bulb culture are usually also favorable 

 for one or more animal pests. The richest soils for growing bulbs 

 generally have the heaviest mole infestation, because of the abundance 

 of mole food. Mice, while fluctuating seasonally in numbers, usually 

 are most numerous where rank vegetation affords food and cover. 



A site on which some of the destructive forms can be avoided may 

 be selected for growing the bulbs. The pocket gopher, as previously 

 stated, is restricted in distribution; the commercial grower should 

 endeavor to plant on land that is free from this pest. Areas adjoin- 

 ing brushy, timbered, or uncultivated land should be avoided if 

 possible, as such lands generally harbor mice and rabbits and, in the 

 Northwest, some moles. It is almost impossible to find a place en- 

 tirely free from pests. 



When an area is selected that is infested with destructive animal 

 pests, every effort should be made to get rid of them before planting 

 the bulbs. Having freed the land from the pests, the grower may 

 take steps to exclude others or to destroy any that succeed in entering. 

 Exclusion is costly and not wholly effective. Methods of destroying 

 the invaders are less expensive and more practicable. 



ACTIVE DETERRENTS 



If there are moles, mice, or pocket gophers on the premises, vigi- 

 lance is the price of success with bulbs and flowering plants having 

 edible root structures. The use of deterrents introduced into the soil 

 at planting time, such as naphthalene flakes and other substances 

 having a more or less persistent and obnoxious odor, has not proved 

 effective in protecting the bulb beds from rodents and moles; nor 

 does putting offensive substances into mole runs at any time, assure 

 the gardener that he will thenceforth be free of the pest. Usually 

 in repairing their runs the animals will bury the material or will 

 dig new burrows near the old. The so-called " mole plants " — castor- 

 bean, milkweed, and others — have been more celebrated in oft-told 

 tales than effective in actual service in keeping moles away from 

 gardens and flower beds. 



EXCLUSION BY BARRIERS 



Deep plowing is advised for breaking up existing mole runways as 

 much as possible. As a temporary protection to a field of growing 

 bulbs an enclosure ditch 12 to 18 inches deep may be made. While 

 this is not a perfect barrier to small burrowing animals, it checks 

 them and makes it possible to detect more readily the entrance of a 



