246 CALIFORNIA VEGETABLES. 



such soil-fitness is found in the peat lands where celery 

 growing has reached the importance above noted. The 

 soil consists very largely of decomposed vegetable matter 

 and becoming on cultivation, fine and homogeneous. It is 

 different from the partially-decomposed and coarse ma- 

 terial of the tule swamps. It occurs in deposits of vary- 

 ing thickness and sandwiched with layers of sediment or 

 clay, the peat layers being, however, connected through 

 the dense layers by openings through which the water 

 rises in springs and sub-irrigates the surface layer. This 

 surface is sometimes treacherous. Much of it will only 

 support horses when shod with plank and some can not 

 be traversed with animals and is worked by drawing tools 

 back and forth with cables from firm headlands on each 

 side. Still it is so productive of celery that even such 

 bottomless land has been rented as high as $20 per acre 

 per year. 



The improvement of peat lands for celery has involved 

 problems of reclamation. First open ditches were resorted 

 to, but as the area of celery culture extended, under-drain- 

 age by tiles was undertaken. By this system the water 

 is absolutely under the control of the growers. When the 

 drains are opened the lands drain until the water is three 

 or four feet below the surface. When drains are closed 

 the water soon rises to the surface, giving a most effective 

 mode of irrigation for which water is pumped into the 

 tile ditches from shallow wells. 



Although these peat lands are very rich at the begin- 

 ning, they soon invite fertilization. A special fertilizer 

 for celery on peat soils is suggested as follows : nitrogen, 

 2% ; potash, 10% ; available phosphoric acid, 5%. About 

 a ton of this mixture can be used to the acre. 



Garden Culture. Celery plants are grown in a seed- 

 bed for transplanting to permanent place. The seed is 

 very small and very slow of germination, and success de- 

 pends upon maintaining even moisture at the surface. For 

 starting plants in winter a hot-bed may be used, but high 

 heat is neither necessary nor desirable. A cold frame 



