146 



THE GARDENERS' CHRONICLE. 



[March 2, 1912. 



ANSWERS TO CORRESPONDENTS. 



a 



* # * The Editors will be glad to receive, for 

 consideration, large photographs of horticultural 



subjects, suitable for reproduction in this 

 Journal. 



Azalea (Rhododendron indicum) : H. F. C. 



Indian Azaleas are usually propagated from 

 cuttings of half-ripened shoots inserted in 

 sandy soil and placed in gentle bottom heat. 

 They may also be increased by layering, or by 

 grafting on stocks of the type. 



Bell-bind (Convolvulus sepium) : A. G. The 



best plan to eradicate the underground stems 

 of this Convolvulus is to trench or dig ths 

 ground deeply and remove and burn every 

 portion of the plant met with. Frequent 



hoeings in summer time would enfeeble the 

 plants, but they are very persistent, and it is 

 doubtful if you would rid the ground of the 

 pest by this means. 



Books : /. W., California. One of the best of 

 the smaller text books dealing with mor- 

 phology and classification is that by Professor 

 Groom, entitled Elementary Botany, which 

 can be obtained from our publishing depart- 

 ment, price 3s. 10d., post free. It is not so 

 easy to recommend a small book giving in- 

 struction in the use of the microscope ; but 

 you will probably find the Elementary Prac- 

 tical Botany of Professor Bower useful 

 for your purpose. — E. Sanders. Natural 

 History of Plants, by Anton Kerner, obtain- 

 able from our publishing department, price 

 31s., free by post. 



Glasshouses for Market Purposes: Constant 



Header. Let the side and end walls of tKfe 

 glasshouses consist of 4^-inch brickwork with 

 9-inch footings, 9-inch piers being built into 

 the 4^ -inch work at intervals of 7 feet on 

 14-inch foundations, and flush with the walls 

 inside. Two rows of piers built as indicated 

 above will support the valley gutters and plates 

 for fixing the rafters to in connection with 

 plates on the side walls and the ridges. We 

 should advise you t# have a 4^-inch division 

 wall between the third and second houses (west 

 side of the block) to enable you to main- 

 tain a higher atmospheric temperature for 

 forcing Roses or Carnations into flower. The 

 walls and piers may be 4 feet high from the 

 floor line. Ventilating boxes, 6 inches wide and 

 15 inches long, should be built into the outside 

 walls, two courses of bricks below the wall 

 plates and between the piers, with shutters 

 attached for opening and fastening from 

 the outside. The items of wood neces- 

 sary in the construction of your three houses 

 are as follow :— Wall and end plates, 3 inches 

 by 4 inches; rafters 1J> inch by 3 inches and 

 about 11 feet long; ridges 1£ inch by 7 inches, 

 these being grooved on both sides' in a line 

 with the bed of the rafters to receive the top 

 square of glass; coping 1 inch by 5 inches, 

 with the upper angles slightly rounded. The 

 door-frames should be made of timber 3 inches 

 by 4 inches (the lentel being bevelled 

 to prevent water lodging), with oaken sills 

 of the same size ; the doors, 6 feet 6 inches by 

 2 feet 8 inches, should be hung on substantial 

 hinges, and provided with galvanised rim locks. 

 The woodwork should receive two coats of 

 paint before being fixed, and a third after- 

 wards. The wood should consist of well- 

 seasoned yellow deal. The rafters should be 

 fixed 18 inches apart by nailing them to the 

 wall plates and ridges of the individual houses. 

 The roofs of houses, 20 feet wide or more, 

 should be strengthened by and nailed to pur- 

 lines, fastened on the rafters and supported 

 vertically by lengths of gas-tubing !£ inch in 

 diameter (outside measurement), resting on 

 brick or cement piers at intervals of 8 or 9 feet. 

 Each span house should be provided with two 

 sets of roof ventilators, one row on either side. 

 The ventilators, 3 feet long and 18 inches wide, 

 should be hung c>n watertight hinges secured to 

 the ridge on either side at intervals of four 

 bays, and the ventilators on one side should be 

 fixed an^lewise to those on the other side, and 

 be regulated by Wolland's or other approved 

 continuous opening gear. The roof should be 

 glazed with 21-ounce glass, using panes 

 18 inches wide and 22 inches ling (stock siz?), 

 six panes to each pair of rafters. B>d the glass 

 in best quality putty. Leave out ths top panes 



in every fourth and fifth pair of rafters wher 

 the ventilators are provided. A transom, 

 lg inch by 3 inches, should be made to fit flush 

 with the upper surface of the rafters, so as to 

 enable the ventilators to shut down quite close. 

 In the matter of staging, you might have a 

 stage along the centre of each house, with a 

 narrower one on either side, with narrow path- 

 ways between the wide and the narrow stages. 

 Employ six rows of 4-inch water pipes in 

 the house partitioned off from the other two, 

 and a No. 2 horizontal tubular or other 

 approved boiler will heat the three houses. 

 The two outside walls should be strengthened 

 from the inside of the houses by iron stays, with 

 a foot, turned up 1 or 2 inches at the end, let 

 into the ground at intervals of 10 feet, about 

 15 inches from the base of each wall, and 

 secured on the top of the wall plates by a 

 coach-bolt. A bucketful of concrete should be 

 put into each hole on top of the foot of the 

 individual stays. 



Imported Orchid : H. S. The plant is a species 

 of Eulophia (some of which are often called 

 Lissochilus), a genus widely distributed in 

 South and Tropical Africa. The species be- 

 long to the chain-rooted section, the flattened, 

 underground tubers forming a series joined 

 at their ends. The plants do not flower until 

 they have formed from three to a dozen tubers 

 connected with each other. The plant col- 

 lector generally collects pieces of one or 

 two tubers, and, when received in gardens, 

 the plants have little chance of grow- 

 ing or blooming. Consequently, when offered 

 for sale they realise but a very low price, 



post- 



er 



-iHLET 



/*L£? 



Fig. 6o. — the 



"harrow" and "gridiron" 



METHODS OF STERILISING SOIL. 



unless they are purchased by someone who is 

 ignorant of their nature. Eulophia having a 

 Phaius-like growth, although very difficult to 

 import, grow well and provide very beautiful 

 flowers. These include L. Horsfalliae and L. 

 giganteus. Another section which includes 

 Eulophia streptopetala and Lissochilus Knebsii 

 are also beautiful and free-growing Orchids. 



Lawn Tennis Court: A. G. As the lawn has 

 made such an exceptionally fine sward, it 

 would be unwise to apply an iron rake for the 

 purpose of scarifying and thinning the grasses, 

 which is only practised when the turf is weedy 

 or moss is present in quantity. By rolling and 

 mowing on frequent occasions, and applying 

 some nitrogenous manure at intervals during 

 the spring, the lawn should continue in a satis- 

 factory condition. 



Names of Fruits : W. Riddell. Golden Russet. 

 — J. W. Miles. 1, Minchull Crab ; 2, Byford 

 Wonder. 



Names of Plants: T. P. A. 1, Abies Pin- 



sapo; 2, Picea excelsa ; 3, Sequoia semper- 

 virens; 4, Thuya occidentalis; 5, Abies cili- 

 cica; 6, A. Nordmanniana ; 7, Thuya plicata 

 (giganteum) ; 8, Cupressus Lawsoniana ; 9, 10, 

 13, 14, C. Lawsoniana; 11, Thuva plicata; 

 12, T. orientalis; 15, T. occidentalis lutes.— 

 N. F. P. A species of Acer, probably A. 

 dasycarpum.— Staffs. Acacia longifolia. 



Pines at Bournemouth: Essex. The majority 

 of the trees are the common Scots Fir, Pinus 

 sylvestris, but P. Pinaster was introduced in 

 1805, and is now locallv abundant and self- 

 propagating. See note on Bournemouth Parks 

 and Gardens by H. S. T. in Gard. Chron., 

 July 16th 1910, p. 38. 



Plants Causing Skin Irritation : E. S. An 



article on plants causing skin poisoning was 

 published in Gardeners 9 Chronicle, August 8, 



from 1 avers or from cuttings. 



1008, p. 110. We know of no series of 

 cards such as you require. 



Prunus triloba : II. F. C. This plant is com- 

 monly propagated by budding it on the 

 Mussel or Myrobella Plum stock ; but it is not, 

 as a rule, satisfactory when worked, the best 

 and longest-lived plants being those obtained 



The latter are 

 rather difficult to root, but, when struck, they 

 make good plants. 



Soil Sterilisation : Constant Header. The 

 subject of apparatus for soil sterilisation is 

 not very far advanced, and there is consider- 

 able room for ingenious and useful work on 

 the part of the horticultural engineers. Good 

 results have been obtained (1) by leading steam 

 into the soil through a series of pipes made of 

 gas-piping shaped like a harrow with nine 

 tynes out of the ends of which the steam issues 

 (see fig. 60). The instrument may be 2 feet 

 6 inches square and tynes 9 inches long ; the 

 best dimensions, however, are not settled. It 

 is placed tynes downwards in a wooden case 

 without top or bottom capable of holding about 

 a cubic yard or more of soil. Soil is filled in, 

 and steam at a pressure of 50-80 lbs. is blown 

 in for 20 minutes. As each yard of soil is done 

 it is thrown into a heap to cool gradually. By 

 having two instruments at work the boiler i3 

 kept constantly going. The heap should not be 

 exposed unnecessarily to rain as valuable plant 

 food speedily forms and is liable to be washed 

 out. (2) A grid-iron instrument may be used 

 in exactly the same manner with a series of 

 small holes drilled in the pipes (see fig. 60). 

 (3) In the United States of America drainage 

 pipes are sometimes laid in the house at about 



9 inches below the surface, steam is then blown 

 in for two hours and allowed to escape through 

 the soil. This method has obvious disadvan- 

 tages for English greenhouse practice. (4) 

 Another American device successfully used for 

 sterilising tobacco seed beds is to make a 

 steam-tight oblong box of stout galvanised iron 



10 feet by 6 feet by 6 inches, lay it on the soil 

 prepared for sowing, and push it down 1 or 2 

 inches, then blow steam in at 80-100 lbs. for 40 

 minutes. On the principle of the warming pan 

 the soil speedily becomes heated. This is some- 

 times done by contract at a charge of J cents 

 per square foot ; its advantage is that it does 

 not necessitate moving the soil from the house. 



Young Vines : F. Spicer and Anxious. Young 

 vines should not be cut back at this stage, 

 or they will bleed freely. They should have 

 been cut back in December, before the sap 

 commenced to rise. When the buds break, 

 rub them off down to the point from which 

 you decide to take up the leading growth 

 which is to form this season's rod. Although 

 it is desirable to take the young growth from 

 as near to the base as possible, in some cir- 

 cumstances you would be quite justified in 

 selecting a growth from 1 or even 2 feet 

 above the ground. For instance, if the front 

 wall of your vinery is 3 or 4 feet high, it 

 would not be wise to take a growth from the 

 base of the vine. If you intend to grow the 

 vines on the single-rod principle, you must not 

 take up more than one leading growth. 1° 

 bring up three growths as you suggest woula 

 rob the permanent rod of much strength, 

 the vines make good progress, you may stop 

 them first when they have made about 5 lee 

 of growth, and twice more before they reac 

 the top of the house. A one-year-old vine w * 

 plant which was propagated from an " eye 

 cutting at the beginning of last year. A .two- 

 year-old vine is one which was propagated t* 

 years ago and cut hard back after the nrs 



or 



season's growth. The plants are 



repotted m 



larger pots when they have started again JJ nto 



rrrowr+k «o~l„ ,* ~ +K« ^ll^.rJnrr vpar. With » 



canes 



growth early in the following year, 

 view to obtaining strong, fruiting 

 These vines are specially grown for fruiting 

 pots. Advice on the treatment of young *&* 

 is given from time to time 

 calendar on the cultivation of 

 Glass/' 



in the weekly 

 "Fruits under 



_A. B- S. 



Communications Received.— H. C. 



—A. 8. & Co E. B., Isleworth_A. P. L. 



A. H. S. A._M. A. K.. Amsterdam— H. R- I>- 

 — H. R., Hollanrl_R. J. W._W. E. B—F. J.--_, M _ 

 W.M., Naples_F. S._T.G. W. H._H. H. 8.--C. *■ ** 

 A. R. W._G. M. T._J. H._W. P. R.-W. B ;r -^ kJ 

 E. S_Oorrespondent _W. A. M._T. P., Wa ^?i\L 

 J. T._W. A C.-W. B. I J ._Anxiou S -W. K , Aberdee 



J. P. P. New Zealand_B. G. A.. " r "— Perpie 

 —J. H. C. 



W. Brown — Perf 



•HHP 



