626 



THE TROPICAL AGRICULTURIST. [March i, 1886. 



few men who from cue cause or another have not 

 been properly grouuded in the operation of potting, 

 and that it is so every gardeuer finds out often to 

 his cost. Recently at a meeting of a gardeners' 

 society, of which the writer is a member, the chapter 

 in Lindley'fi "Theory of Horticulture," which treats 

 on potting, was read and discussed ; and although 

 everyone seemed to think he knew how to pot a 

 plant properly, much was said that showed how 

 some at least did not riphtiy comprehend the oper- 

 ation, whilst one or two supported views which if 

 acted upon could not but result in disastrous conse- 

 quences. This, therefore, is the excuse for writing 

 a chapter upon the sutiject. 



Some useful advice was given by Mr. Muir at 

 page 232 on how to drain flower pots ; but one or 

 two flaws occur in what he has said — notably where 

 h e suggests that an inverted pot should be placed 

 over the hole in the bottom of large pots. Now we 

 all know that the first object to be attained by drainage 

 is a free and const-ant outlet for the water from 

 the soil above, and thus it is that where crocks 

 only are used we are always careful to place over 

 the hole at the bottom of the pot a large one with 

 the concave pide downwards. But a small even- 

 rimmed pot placed over the hole i& practically the 

 same as placing a flat crock or a piece of glass 

 over it. This will be apparent to anyone who observes 

 how closely the rim of a small pot when inverted 

 over a flat surface will touch all round. By break- 

 ing a few nitcbes in the rim of the small pot to be 

 used as drainage the danger of blocking the hole 

 of the pot drained is obviated. In Liudley's book 

 an excellent plan is mentioned for preventing worni.s, 

 &c., getting into the pot through the hole at the 

 bottom when placed upon the ground. He says, "To 

 remedy this I put at the bottom a piece of per- 

 forated zinc so as to completely cover the hole. 

 Upon this a large crock is placed with the convex 

 side upwards." For large plants ^/liich are stood out 

 of doors during a portion of the year this zinc trap 

 seems an excellent suggestion. 



The depth of drainage used always varies with 

 the requirements of the plant — Orchids and a few 

 other plants, generally epiphytal ones, requiring a 

 larger amount of drainage thnu others. Bearing in 

 mind that for plants which are intended to remain 

 in the same pot for several years the more drainage 

 used the less soil room there is, it will be seen 

 that a thin layer of crocks if properly placed will 

 be better than a thick one. The roots of a plant 

 when growing in a pot very soou reach the bottom, 

 where they generally continue growing round, ami 

 seldom — with strong-rooted plants never— find tlieir 

 way baok into the soil again. Where a thick layer 

 of crocks is used it will be seen that the majority 

 of the feeding roots have no food supplied them 

 other than that contained in the water when pass- 

 ing through the soil and rocks. AVhere crushed bones 

 are used as drainage the case is different, as the 

 bones afford more nourishment to the roots than 

 ordinary soil would. If a shallow layer of soil is 

 preferred it is always advantageous to use shallow 

 pots or pans instead of having a deej) layer of drain- 

 age beneath the soil, which has the effect of allow- , 

 iug the wator to escape from the soil tjuicker than , 

 is good for the plant. So long as .stagnation is pre- 

 vented it is better for all terrestrial plants that j 

 they be so situated as to have the soil about tlieir I 

 roots kept moist without too frequent waterings, the 

 effect of which is to completely decompose the soil i 

 or make it sour. For plants in very warm houses | 

 this precaution is of special importance. I 



Shiftiny plants into pots of larger size is an operation ' 

 requiring some knowledge of the nature of the 

 plants, and also depends not a little on the health 

 and size of each. Consideriug first those plants wl.ich 

 are slow growers, and therefore do not extend | 

 their roots very far in a year, such as Ericas, Epacrises, 

 Pimeleas, and other hardwooded plants, the (iiu;stion 

 arises, is it better to treat these plants on the one- 

 shift syAtem, as recotumended by Dr. Liudley, or ! 



to give them repeated shifts, such as would be no 

 more than the roots would take complete possession 

 of in a year? If it is admitted that soil deterior- 

 ates rapidly when frequently watered or when placed 

 in heat, it must be apparent that to place a plant 

 in a large body of soil which could not be occupied 

 by the roots for several years is a system not to 

 be recommended. There can be no question of the 

 many advantages of the repeated or gradually in- 

 creasing shift over that of the one-shift sj-stem — 

 that is for plants which are being grown from small 

 into large specimens, and which are slow growers. 

 Many plants — such, for instance, as Pelargoniums, 

 Balsams, Fuchsias, &c. — will under favourable treat- 

 ment grow to a very large size iu a single season, 

 8ome of the softwooded quick-gowing Heaths also 

 considerably increase in size in a year: for all such 

 plants a much larger pot is advantageous. But we 

 must remember that with very few exceptions the 

 plants we grow are wanted to flower every year. 

 Now, it is a well-knowr fact that under ordinary 

 conditions a plant in a pot of proper size — i.e., such 

 as its roots would about fill iu a year — flowers more 

 freely than when planted out, or when grown in a 

 larger pot than is required for one season's growth. 

 The pot cramps the roots, causes the wood to mature 

 quickly, and so induces the plant to flower. AVe 

 know that the smaller the pot under ordinary con- 

 ditions the greater the dispo.sitiou to flower, so that 

 by placing our plants in pots containing only enough 

 soil to afford them the conditions required for the 

 growth and maturation of the wood formed in one 

 season, we are eusured a supply of flowers which 

 would probably otherwise have failed us. From 

 this it will be s^r^en that the safest and best system 

 to adopt with regard to repotting and shifting is 

 the annual and not the one-shift system, or, in 

 other words, the placing of the plant at an early 

 stage of its growth in a pot large enough to contain 

 it for the following six or eight years. 

 ■ Shifting plants is a different operation from that 

 of shaking out and repotting, which is practised only 

 for such plants as are deciduous or require a long 

 season of complete rest. This operation is usually 

 performed after the plants have been rested, cut 

 cack, or pruned, and started into growth again. As 

 soon as the buds begin to show signs of activity is 

 the time to shake out from the roots of the plants 

 all the old soil and prune the roots somewhat, after- 

 wards placing them in pots of a size only large 

 enough to att'ord them support for a few weeks. 

 Whatever may be said to the contrary, there can 

 be no question as to the wisdom of this method 

 as comiiared with that sometimes recommended, and 

 whicli is to repot the plants during their rest and 

 not before j/rowth has recommenced. A little con- 

 sideration of one of the simplest laws of plant 

 physiology is sufhcient to condemn the latter practice. 

 (It must be borne in mind that we are now dis- 

 cu.ssing plants cultivated in pots, which afford con- 

 ditions very different from those to which plants 

 growing naturally are exposed.) 



The firmness of the soil is another point of some 

 importance to the cultivator of plants in pots. Some 

 growers, successful ones too, put the softest wooded 

 and quickest growing plants much firmer than m««ny 

 would advise. Some of the best IVlargoniums I have 

 ever seen were grown iu a stifT loam pressed down 

 as hard as a hrick. Tlu sc plants wt're in rather 

 small pots, but it Avas a revelation to one who liad 

 been taught to pot hardwooded plants very firmly 

 and softwooded plants loosely. A prize Mignonette 

 grower used to say h:s success was due to hard pot- 

 ting and bones, and his plants were in soil as hard 

 almo&t as stone. They were bush and standard 

 Mignonettes, such as we seldom Fee 'now. In this 

 matter, however, much depends on the quality of 

 the soil and the aim of the cultivator; still, the fol- 

 lowing general rules may be pointed to — viz., all 

 fine-rooted plants may be potted firmly (;dways except- 

 ing annuals), very fine-rooted plants with hard wood 

 requiring the soil to be rammed hard. The harder 



