10 



CIRCULAR 



1, U. S. DEPARTMENT OF AGRICULTURE 



CONCRETE WALL 



METAL FORM 



TRENCH 



mole or a pocket gopher into the planting. These should then be 

 trapped at once. 



Some protection of bulb beds against moles and burrowing rodents 

 in gardens, lawns, and parks may be insured by providing a fence of 

 galvanized hardware cloth, %-inch mesh, 36 inches wide, buried 30 

 inches, with 6 inches turned out at the bottom. 



Where certain valuable plants require special protection, particu- 

 larly from moles, and the plot for their propagation is sufficiently 

 permanent^ simple concrete barriers (fig. 5) 1 inch or more thick 

 have been found more durable, and hence cheaper in the long run, 

 than the galvanized hardware cloth. They may be constructed with 



comparatively small 

 outlay for labor and 

 materials as follows : 

 Pour a cement mix- 

 ture between the 

 outer vertical bank 

 of a narrow ditch 

 and a movable 20- 

 gage sheet-metal 

 form (3 by 3 6 

 inches) placed to 

 support the concrete 

 temporarily on the 

 inner side. Such a 

 barrier need not be 

 more than 1 inch 

 thick and should 

 be 30 inches deep. 

 Moles and pocket 

 gophers rarely go 

 deeper in search of 

 food. The metal 

 forms are to be kept 

 in place 1 inch from 

 the outer bank while 

 the ditch is being- 

 filled on both sides 

 at the same time — 

 concrete on the outer 

 side and earth on the inner side, as moles would be less likely to burrow 

 down through the solid outer earth than through the fill, xls the 

 filling proceeds the metal forms are pulled out and shifted farther 

 along, one at a time, without waiting for the cement to dry. Two or 

 three such portable forms will be needed to keep the work going. An 

 inch of one edge of the forms may be bent at right angles to strengthen 

 it and to serve as a handhold. A mixture of 1 part portland cement, 

 2 parts sand, and 3 parts gravel (not too coarse) is recommended for 

 the 1-inch wall. 



'igure 5. — Method of construction of concrete barrier 

 1 inch thick and 30 inches deep, to exclude burrowing 

 animal pests from areas where certain valuable plants 

 require special protection. Concrete is poured on the 

 outside of the metal form while earth is filled in on the 

 bed side, after which the form is moved forward with- 

 out waiting for the concrete to dry. 



TRAPPING AND OTHER CONTROL MEASURES 



Fencing or otherwise excluding burrowing pests is not always 

 practicable. In most cases it will be necessary to supplement this 

 method of control by trapping and other means. 



