296 CALIFORNIA FRUITS: HOW TO GROW THEM 



with German knitting yarn, not with raffia. The season for herbace- 

 ous grafting will, of course, vary according to the locality. Hot 

 weather immediately following the work is fatal to most of the grafts 

 If two or three cool days follows the insertion of the scions he obtains 

 an almost perfect stand. 



Care of Scions. Scions should be kept cool and moist enough 

 to prevent drying but not wet enough to cause decay, as has already 

 been described in the keeping of cuttings. 



Time of Grafting. Grafting into old vine stumps is done in 

 February, March and April in different parts of the State, March being 

 the month usually chosen for the work. If a spring graft fails, the 

 stump may be regrafted in August or in the following spring. In 

 regrafting, the stump is cut oft" again below the previous cleft. The 

 time for the work is when the sap has ceased flowing, usually from the 

 first to the tenth of August. 



Resistance to Phylloxera. The recourse to resistant roots to 

 escape the phylloxera has been attended with some disappointment 

 because the wild roots at first widely used proved only partially resist- 

 ant. Recently, in the main through employment of French selected 

 varieties of the American wild species, stocks with satisfactory resist- 

 ance, larger growth and vigor and adaptation to different California 

 soils have been secured. Notable success has been attained in the 

 habilitation of vineyards on the basis of resistant roots. As this under- 

 taking involves considerable outlay and as success depends taking 

 advantage of the latest demonstrations of the affinities of varieties, the 

 adaptations of roots to soils and the suitability of varieties for special 

 purposes, the latest information should be had from the University 

 Experiment Station at Berkeley, before making investments. 



The Cutting Graft Grafting the desired variety upon a resist- 

 ant cutting, putting these cutting-grafts through a callusing bed and 

 then planting the grafted cutting in nursery for rooting is an accepted 

 French method which is being successfully employed in California. 

 This has advantage in time gained and in securing a full stand of vines 

 as compared with grafting upon cuttings already rooted in place in the 

 vineyard though the latter has been successfully practiced. 



If cutting-grafts are placed directly in the nursery many will fail. 

 For this reason it is always best, except at the extreme end of the 

 grafting season, to "stratify" the grafts in a "callusing" bed, where 

 conditions of moisture, temperature, and aeration can be controlled. 

 This callusing bed is usually a pile of clean sand placed in the south 

 end of wall or building surrounded by a board partition where there is 

 no possibility of its becoming too wet by the flow of water from a 

 higher level or from an over-hanging roof. It should be protected, if 

 necessary, by a surrounding ditch. It should be furnished , with a 

 removable cover of canvas or boards to protect it from rain and to 

 enable the temperature to be controlled by admission or exclusion of 

 the sun's rays. A waterproof wagon-cover, black on one side and white 

 on the other, is excellent for this purpose. 



