190 



IRISH GARDENING. 



The General Culture of Tropical 

 Plants. 



By J. A. Cavanagh, The Gardens, Portrane. 



TO attain even a moderate deg^ree of perfection in 

 the cultivation of tropical plants one must gfive 

 close attention to certain underh'inj^- principles 

 of culture. For example, we must observe a careful 

 nicet}' in pottins^ and shifting: i'l tlit? proper season, 

 reg-ularity in vvateringf, and with due regfard to the plant's 

 period of gfrowth and to the conditions of the weather. 

 We must have a knowledg^e of the temperature necessary 

 for each subject, and gfive a steady attention to the clean- 

 liness and liabits of the plants in general. The operation 

 ol' shifting- or refreshing- the roots of plants with earth 

 |-)roperly prepared for that purpose, by transplanting- 

 theni into larg-er pots than they before occupied, is one 

 of the most essential operations to assure a healthy 

 growing- state. The quantity of earth contained in a 

 plant-pot being-, in comparison, so small to that which is 

 requisite for the support of the gfenerality of plants 

 growing- under natural conditions, it must be supposed 

 that, unless it is chang-ed or aug;mented in due season, 

 tlie plants will soon exhaust all the available food at the 

 (.lisposal of the roots. The effect of this upon the more 

 tender subjects, especially if accompanied by insufficient 

 drainagfe, will be ill-health and liabilit)- to disease, while 

 to the strong-er g-rowing- specimens it means partial 

 starvation followed by poor g-rowth and unsightly 

 plants. 



The season most suitable for shifting- hot-house plants, 

 especially those of a woody character (to which our 

 remarks are intended), is just as they are becoming: 

 active or starting- new gfrowth in spring- time. The bulk 

 of these plants will be found ready for this treatment in 

 March. If taken in liand before that time the g-reater 

 part of the collection will be found dormant or nearly so, 

 thoug-h there are instances of plants being- in g-rowth for 

 the g-reater part of the year. If shifting- is performed 

 while certain plants are inactive, they will not have suffi- 

 cient power to establish themselves in the fresh earth to 

 prevent the loss of leaves ; and, on the other hand, if 

 tlone when g-rowth is far advanced, it will require infinite 

 care and increase of labour to keep the proper balance 

 between the loss of water b\- the leaves antl the grain of 

 water by the disturbed roots, so that in this case, too, 

 the foliag-e is likely to suffer. But if the plants be taken 

 soon after starting- the new season's g-rowth, the root 

 fibres are then active and, g-iven the necessary warmth, 

 will soon push their way into the fresh mould, and by 

 the time the young- shoots lengthen and expose their 

 foliage the root S3-stem will be extensive enough to 

 cope with the supply of water required by the young 

 leaves. 



Operation of Shifting. — Being fully prepared with all 

 the requisites, thoroughly cleaned and well drained pots, 

 also suitable composts ready for the various species, let 

 a part of the plants be taken to the potting shed or place 

 assigned for the work, or, better still, a temporary bench 

 erected in the stove or plant house. This latter precau- 

 tion will obviate any risks from exposure which plants 

 may be expected to get when carried out of a high 

 temperature. In transferring the plants the greatest 

 nicety should be used, because if the roots, from a 

 multiplicity of wounds (which are more frequently 

 lacerated than cleanl}' cut), once become ''cankered" 

 or decayed it is only reasonable to expect that the 

 branches will suffer in proportion. 



An erroneous practice followed by the uninitiated is 

 that of paring off the best part of the roots with a knife — 

 that is, the roots outside the ball of earth — in other 

 words, the tips or fibres which are undoubtedly the 

 feeders or active agents in supplying the plant with food. 



Though this method may not seem to injure some few 

 kinds of strong free-growing plants, yet it can never be 

 allowed as a proper mode of treatment for all plants 

 indiscriminately. There are instances, however, wherein 

 the use of a knife is necessary to the roots as well as to 

 the branches — viz., when they become injured or in 

 cases where we use either the root or suckers for pur- 

 poses of propagation. In all such cases as these the 

 roots should be taken off with precision, and a sufficiency 

 of roots left to support the parent, if considered worth 

 preserving-. 



In turning the plant carefully out of the pot observe 

 if the roots iiave perforated it in any part so as to render 

 it impossible to part them without breaking the c>ne or 

 lacerating the other, in which case prefer the former as 

 causing the slightest damage. When the ball of roots 

 has been divested of its pot, let the broken tiles, or what- 

 ever material has been used for drainage, be carefullv 

 l-)icked out without injuring- the roots which may have 

 minified amongst them ; also any caked, sour or mossy 

 substance on the surface. Then proceed to loosen the 

 old worn-out soil, and at the same time disentangle the 

 matted roots. If the soil is dry this is best done by 

 gently tapping the ball with the hfuid, or otherwise 

 pressing it so as to open the interioi- without cracking- 

 the root ; then shake off all the loose earth, and have 

 a proper sized pot prepared — that is, well diained and 

 some of the coarsest compost made firm in the bottom — 

 and sufficient of the soil put in so that when the plant 

 when finished will have some fresh earth over the surface 

 roots, and allowances made which will permit of ade- 

 quate watering space between the base of the stem and 

 rim of pot. 



When the operation of shifting is complete, some of 

 the more tender species may require to be plunged to 

 half the depth of the pot in the warmest pit and the re- 

 niainder arranged neatly on the benches or staging. 

 These latter should be thoroughly cleaned before re 

 arrangement, as the staging very often offers a hiding 

 place for pestiferous insects which infest this department. 

 A prett}' brisk fire heat may now be kept up luitil the 

 plants recover from their inactive state, the miavoidable 

 consequences of having their roots so recently disturbed. 

 They will be much benefited at this period by a moderate 

 use of the hand syringe in the mornings and evenings, 

 when the sun does not act upon them with force ; also 

 by raising a strong steam or moist atmosphere b}- 

 throwing water on the warm flues or pipes. \\'hen the 

 plants are freely treated in this manner they require but 

 little from the watering pot, as over-watering is very 

 pernicious to plants in general, and at no time is it more 

 particularly so than when they have been lately potted. 

 It is not, of course, the over-abundance of water that is 

 harmful, but that the roots are deprived of air, the water 

 filling up the soil spaces that ought naturally to be filled 

 with air. However, watering must unavoidably depend 

 on the judgment of the person who undertakes the 

 culture of tender exotic plants. 



Little more attention will now be necessary for a few 

 weeks beyond watering when necessary, syringing, 

 steaming, and keeping up the requisite degree of heat ; 

 this should be about 65 degrees. If kept much lower it 

 will considerably retard the plants in recovering their 

 vigour, and if allowed to gain a very high temperature 

 the free-grc^wing kinds will be apt to become top heav}-, 

 which will materially injure the more weak and tardy 

 growing sorts, besides the plants themselves will become 

 unsightly consequent on being drawn or unduly forced 

 into long, weak, and ungainly stems. 



^* ^^ ^^ 



" Flowers are thoughts of the Spirit of God, 

 Their love is love of His grace, 

 Their fragrance is breath of diviiiit}-. 

 Their beauty the light of His face." —Hodgf. 



