628 



THE GARDENER'S ASSISTANT. 



CHAPTER XXXIX. 



RETARDING PLANTS. 



In contradistinction to forcing or accelerat- 

 ing the growth of plants by the application 

 of heat, we have now the practice of retard- 

 ing or holding back growth by the application 

 of a low temperature, artificially produced by 

 means of air-compressing machines and freezing 

 mixtures from the combination of ice and salt. 

 Plants, roots, and bulbs of various kinds which 

 have been kept in a freezing temperature for 

 weeks or months will, when placed in a little 

 warmth, grow and develop their flowers with 

 the same vigour and perfection as when treated 

 naturally. Everyone must have noticed that 

 vegetation is at a stand-still when locked up 

 by winter frost and snow, and that under the 

 effects of spring warmth and sunshine growth 

 begins, as it were, with a sudden rush. 



" Nature herself forces her flowers during 

 mild or warm and showery weather, and she 

 also retards them during prolonged frost. 

 Herein lies the principle on which the gar- 

 dener has been practising for the past two 

 or three centuries or more, but so far he has 

 done more in the direction of the application 

 and conservation of natural and artificial heat 

 than in that of the judicious application of cold 

 temperatures. But all this is now altered, and 

 in future great developments may be expected 

 from cold storage and the refrigerating chamber 

 as modern horticultural appliances. Hardy 

 plants that lose their leaves in autumn will 

 be so treated that nature's strength and sun- 

 stored vigour will lie quiescent, it may be, for 

 the time, but full of suppressed life, ready 

 coiled up, as it were, for a spring when re- 

 moved to a moderately warm and genial 

 atmosphere. Not merely flowers, but vege- 

 tables, such as Rhubarb, Sea-kale, and many 

 other things, may be treated in modern fashion 

 by retardation. But perhaps the greatest gain 

 will be in the application of the retarding 

 process to hardy deciduous fruit trees in pots 

 or otherwise, so that we may have crops of 

 fresh Cherries and Plums or Peaches and 

 Grapes any day in the year, and with far 

 greater certainty or precision and much less 

 trouble and labour than is at present the 

 case." — Field. 



In the nursery of Mr. Thomas Rochford, 

 near Cheshunt, there are four refrigerating 

 chambers of a capacity of about 65,000 cubic 



feet, in which roots, bulbs, &c, are stacked in 

 single layers in such a way as to allow of a 

 circulation of freezing air amongst them. This 

 air is supplied by a large engine, worked by 

 two large marine tubular boilers capable of 

 reducing the temperature of the chambers to 

 90° below freezing-point; it is not, however, 

 necessary to maintain a temperature anything 

 like so low as this. 



When the plants are removed from these 

 chambers they are placed at ..first in a tem- 

 perature of 45° or 50° for a few days, and 

 kept shaded until they have made some 

 growth, when more light and heat are af- 

 forded. 



Azalea mollis, after having been retarded, requires 

 a moist, shady position and frequent syringing until the 

 buds burst, when more light and heat may be afforded. 



Hoteia {Spiraea) japonica, and H. palmata, which 

 have been retarded, start into growth very quickly if 

 placed in a cool house and kept shaded until they have 

 made new roots. They take from five to eight weeks to 

 flower. 



Lilium. — These require care to prevent the growth 

 from pushing in advance of the roots, which will have an 

 injurious effect on the blooms. They should be kept in a 

 cool, shaded position until they are well rooted. To get 

 them into bloom at any particular period a little extra 

 warmth may be given after the buds begin to show, but 

 the flowers lose substance in consequence. 



Lily of the Valley is particularly amenable to this 

 treatment, the retarded crowns starting as freely and as 

 vigorously as those treated in the ordinary way. When 

 taken out of the retarding chamber, they should be 

 started in a cool house in shade and moisture, covering 

 them with moss or some other light material for a few 

 days, and in about three weeks they will be in full 

 flower ; in autumn and winter they may take a week or 

 so longer. 



CHAPTER XL. 

 SPKING BEDDING. 



The objections made against some forms of 

 summer bedding do not apply in the case of 

 what is known as spring bedding, or filling the 

 flower beds in October with plants to flower in 

 the spring. These spring flowers are always 

 welcome; and no matter how exposed the 

 situation may be, a number of plants may 

 always be found to brighten it in the early 

 portion of the year. The ideal situation for a 

 spring garden is a warm hill-side, sloping to the 

 south, and sheltered on the north, east, and 

 west sides with trees, chiefly evergreens, and if 

 a few groups of trees and shrubs are planted 

 on the south side, some distance from the beds, 

 they will afford shelter from the south-westerly 



