30 HORTICULTURE BY IRRIGATION. 



not desirable and should never be placed in contact with the body of the 

 tree. There is less necessity of a dressing where the soil is naturally 

 warm, deep and mellow, with a moist, sponge-like sub-soil. This kind is 

 in a measure self-protecting, because it not only keeps the surface of more 

 even temperature, but brings about a most desirable condition that of 

 deep rooting. 



But where trees are to be planted in situations unprotected from the 

 direct action of the sun and the elements, mulching should always be 

 applied. The advantages are that it tends to guard against sudden 

 extremes of temperature, to retain both surface and capillary moisture, 



MANNER OF PROTECTING THE TRUNKS 

 OF TREES. 



Fig. 3. 

 Gunny-sack 

 or .Burlap. 



Fig. 4. 

 Heavy paper. 



Fig. 5. 

 Boards. 



Fig. 6. 

 Stakes or lath. 



protects from the at times too powerful and long continued heat of the 

 sun, and in other ways equalizes conditions. Whatever virtue there may 

 be in the atmospheric ammonia given off by the rains, or in the sub- 

 stances deposited by the irrigating waters, the mulch assists in utilizing. 

 The generally accepted theory is then that a good mulch both operates as 

 a protection and a fertilizer. 



Mulching does not retard the blossoming period in trees as was form- 

 erly supposed. It could have this effect only where the tree was entirely 



