31 



should be even better drained than that supplied to normal 

 plants. A soil made porous by the plentiful admixture 

 of sand should always be selected, and m the case of 

 cuttings which are being struck in pots, it is a common 

 practice to insert them close against the inside of the 

 porous pot, through w^hich the air has a free access to the 

 cuttings. The danger of over w^atering cuttings is even 

 greater than in the case of well-established plants. Cut- 

 tings taken from woody plants produce their wound 

 tissues as well as the adventitious roots, w^hich are formed 

 later, at the expense of the food material which is stored 

 in the shoot. They are not therefore so dependent on 

 ivarmth and light in the early stages as are herbaceous 

 cuttings. They can indeed be struck in the autumn or 

 w^inter after the leaves have fallen, or in the early spring 

 before the foliage has been developed. If taken in the 

 autumn they often do not produce their roots until the 

 following spring, and they are alw^ays later in the develop- 

 ment of their leaves than are well-established plants. In 

 the case of herbaceous cuttings which have no store of 

 food material, it is necessary that they should be able to 

 continue to form new organic food material in their leaves 

 so as to promote the growth of callus and the development 

 of roots. It is esential therefore that they should have 

 plenty of light ; but in the first few days before they have 

 adapted themselves to their new conditions, they are liable 

 to lose too much water by evaporation, and it is important 

 during this period to keep them slightly shaded, or to 

 grow them in a moisture-laden atmosphere in a closed 

 frame or greenhouse. It is better to prevent the loss of 

 too much w^ater by protecting the leaves in this way than 

 by excessive supply of water to the soil, as herbaceous 

 plants are very liable to decay by the action of bacteria 

 on the cut end of the shoot. As herbaceous cuttings have 

 to continue to manufacture food material, they also require 

 a greater amount of heat than do woody cuttings, the 

 process of leaf nutrition being stimulated by an increase 

 of temperature. Herbaceous cuttings must, therefore, not 

 be taken too late in the autumn unless they are to be grown 

 in artificial heat. 



A few plants can be raised from root cuttings. This 

 is possible where plants are endowed by nature with the 

 power of forming adventitious buds on their roots. Rasp- 

 berries, Pears and Apples are all exam.ples of plants which 



