POTTING AND REPOTTING OR SHIFTING. 297 



gioles, or the soil must be shaken off from the roots entirely, the roots 

 cut in, and the plants inserted in the smaller pot among fresh soil. In 

 shifting plants from one pot to another, care should in general be taken 

 not to place the collar of the stem deeper in the new pot than it was 

 before in the old one, excepting in the case of plants which root readily 

 from the stem, such as balsams and a few others ; but in general, in 

 pots as in the open ground, the stem should rise from a gentle eminence, 

 and the ramifications of the upper roots, where they depart from the 

 stem, should be seen above the soil. 



Seasons and Times far Potting and Shifting. Small plants may be 

 potted at any growing season ; but the most favourable are spring and 

 autumn, and the least so mid-winter, even under glass, owing to the 

 absence of light. Shifting also may be performed at any season ; but the 

 most suitable for established plants is just before they commence their 

 annual growth, or just after completing it; while young rapidly-growing 

 plants may be shifted from time to time as long as they continue growing. 

 Slow-growing woody plants are seldom shifted oftener than once a year, 

 unless it is desired to accelerate their growth; but rapid-growing 

 plants, such as pelargoniums, and such annuals as the balsam, cocks- 

 comb, &c., are shifted many times in a single season, beginning, more 

 especially in the case of the balsam, with a pot of the smallest size, and 

 gradually increasing the size as the plant advances in growth, till from 

 being 2 inches high in a pot of the same height in April, it is 3 feet or 

 4 feet high in a pot 1 foot in diameter in June or July. By heat and 

 frequent shifting for upwards of a year, pelargoniums are grown so as 

 to form bushes 3 feet or more in diameter in pots of not more than 

 8 inches or 10 inches across. Pine-apples are grown to a large size in 

 comparatively small pots, but the soil employed is rich and frequently 

 supplied with liquid manure. 



The most difficult plants to manage in pots are the hair-rooted 

 kinds, such as all the Ericaceae, and many Cape and Australian shrubs 

 requiring sandy peat soil, which must be well drained, and kept uni- 

 formly moderately moist, but never either soaked with water or very 

 dry. The drainage must be so perfect as to prevent the possibility of 

 water stagnating in the soil ; and while the nature of this soil, sand 

 and peat, readily permits the water to pass through it to the drainage 

 below, the porous sides of the pot incessantly carry off moisture by 

 evaporation, and the more so as heaths require to be kept in a rather 

 dry atmosphere. The roots of heaths, and indeed all hair-like roots, are 

 as readily destroyed by over-dryness as by moisture, and hence the con- 

 tinual risk of danger to this description of plants when grown in pots. 

 To guard against the extremes of dryness and moisture, the pots when 

 small are sometimes plunged in sand or moss, or placed in double pots ; 

 or when the plants are large, shifted into wooden boxes or slate tubs. 

 To provide against excess of moisture on the one hand, and the want of 

 it on the other, two very ingenious and useful practices have been 

 introduced into the culture of heaths and heath-like plants in pots, 

 by Mr. M'Nab. The first is, always to keep the collar of the stem of 

 the plant a few lines above the general surface of the pots, in conse- 



