130 



THE GARDENERS' CHRONICLE. 





[February 24, 1912. 



ANSWERS TO CORRESPONDENTS. 



Acetyi .ene-gas Refuse : Seakale. Aeetylene- 

 gas refuae should be mixed with soil in a heap 

 and kept for a month or two before it is spread 

 ever the ground 



Am>ki:ss: New Reader: Lieut. -Col. D. Prain, 



Director, Royal Botanic Gardens, Kew, Sur- 

 rey . 



Alm'le -tf.ee Bark Destroyed: S. E. X. We 

 are unable to say whether or not the Apple 

 tree can possibly "live, as we do not know how 

 deeply the goat has injured the bark. If the 

 tambian layer is destroyed completely round 

 the tree there is not any hope, but you will 

 do well to cover the injured stem with styptic, 

 such as is used for covering wounds after graft- 

 ing to prevent bleeding. 



Calantiie: Foreman. It is better to retain the 

 deciduous Calauthes in their pots during the 

 resting season, but they must be given 

 a warm and tolerably dry situation and 

 not stored under a stage, where drip 

 and stagnant air would injure them. If 

 space is very limited, however, they may 

 be turned out of the pots when the plants 

 are thoroughly matured, and placed upright 

 in boxes, their roots covered with a thin layer 

 of Sphagnum-moss. The boxes should be 

 stored on a shelf in a warm house and kept 

 dry until the growth is about to recommence, 

 when the plants must be repotted. 



Camellia Buds Rotting: J. W. B. The mil- 

 dew present on the leaves is not injurious, but 

 it is a sign that the atmosphere has been too 

 damp. Excess of moisture and insufficient heat 

 are the causes of the buds falling. 



Certificate in Botany: E. J\ Examinations 

 are held by the Hoard of Education in botany, 



and you should apply to the Board for further 



information. Address, the Secretary, Board 

 of Education, Whitehall, London, S.W. 



Cinerarias Unhealthy: C. W. Your plant of 



Cineraria is suffering from too much water in 

 the soil , the loam is apparently sati- ictory. 



M. Fritzer: F. C. This 



abundant litrlit and air. 



Crassuli. M. Fritzer : /'. C. This plant 

 requires abundant light and air. Very 

 little moisture should be afforded, especially 

 during the winter season. The cuttings 

 should be inserted as soon as the plants 

 have finished flowering, say, in June ^ or 

 July. They should be kept on the dry side, 

 in a light, airy house, where they may be 

 allowed to remain throughout the winter, only 

 affording heat sufficient to keep out the frost. 

 If too much moisture is afforded, the plants 

 will grow freely, at the expense of flowering. 

 Specimens frequently fail to bloom until they 

 are two years old ; such plants should be used 

 for purposes of propagation. 



Gri*bs Infesting Branches of Choisya: G. G. 



The grubs are those of a dipterous fly, possibly 

 a species of Cecidomya or allied genera. The 

 only practical remedy, so far as we know, 

 is to cut away the infested shoots and burn 

 them. 



Japanese Nursery Firms: 11. F. C. Yoko- 

 hama Nursery Co., Craven House. Kingsway, 

 London : L. Boehmer & Co., 5 and 28. Bluff, 

 Yokohama ; and The Tokio Nurseries Co., 



Komagome, Tokyo. 

 Jasmintjm and Pelargonium: A. W. G. The 



marks on the Pelargonium leaves are caused by 

 mites. Wash the foliage with Tobacco water. 

 The browning of the Jasminum blooms is not 

 due to disease. 



Leaves Injured by a Mining Insect : Hortus. 



The leaves — which are apparently of Hibiscus 

 svriacus — have been injured bv the mining 

 maggot of the Marguerite fly. Spray the plants 

 with quassia extract or other distasteful liquid, 

 in order to prevent the females from depositing 

 their eggs upon the leaves. Remove badly- 

 affected leaves and burn them. 



Names of Plants : Correspondent (no letter was 

 found). 1, 2, 5, 6, 7 and 8, varieties of Cupres 

 sua Lawsoniana; 3, Thuya dolabrata ; 4, 

 Cupressui nootkatensis pendula ; 9, Picea 

 morinda ; 10, one of the garden forms of 

 Veronica speciosa ; 11, Cryptomeria elegans. 

 The various forms of Law son Cypress cannot 

 be recognised from small pieces of the branches. 

 It is the most variable Conifer known, and 



forms showing quite as much variation as 

 those vou send may appear in any batch of 

 seedlings.— M. L. Polygonum aviculare 

 " Knot-grass. ' f —C. Stapler. 7, Cryptomeria 

 japonica var. elegans; 8, Picea pungens var. 

 glauca ; 9, apparently Juniperus virginiana ; 

 10, Pseudotsuga Douglasii ; 11, Thuya dola- 

 brata : 12, Abies Nordmanniana. — R. 0. 1, 

 Begonia f uchsioides ; 2, Eranthemum pulchel- 

 lum; 3, Oncidium flexuosum; 4, Selaginella 

 Wildenovii. — Ajax. Tiarella cordifolia. 



Peach Dying : H . B. and T. W. C. The symp- 

 toms suggest " die-back/' caused by a fungus. 

 It will be best to remove the badly-injured 

 shoots, and wash the branches once a week for 

 three or four weeks with a solution of liver of 

 sulphur, using 1 ounce in 3 gallons of water. 



Plant Breeding : //. C. B. The best course for 

 you to adopt is to write to some of the nur- 

 serymen who make a speciality of breeding par- 

 ticular strains of plants, and try and make 

 arrangements with them to give you employ- 

 ment in the plant department. There is a 

 special station for research in heredity and 

 plant-breeding at Merton, Surrey. This insti- 

 tution is under the direction of Professor Bate- 

 son, and he would doubtless advise you as to * 

 whether it would be possible for you to obtain 

 employment there, and whether such a course 

 would serve your interests. 



Poiatos Diseased : Sterlini. The tubers are 

 affected with winter-rot, caused by a fung 

 This disease is usually the result of Potatos not- 

 being well air-dried before they are placed in 

 the pit. 



Potting Hippeastrums : Constant Header. 

 Different growers adopt different methods, for 

 whilst some only repot their plants every two 

 or three years, others do so annually. In 

 both cases the general practice is to repot or 

 afford surfacings of fresh compost in spring 

 as the bulbs show signs of new growth. A 

 mixture of turfy loam, leaf -mould, and silver 

 sand is a suitable rooting medium. When the 

 bulbs are growing freely and whilst the 

 flower-spikes are developing liquid manure 

 should be given. After the period of flower- 

 ing is over and the growth completed, the 

 bulbs should be rested in an airy greenhouse 

 or vinery, but a little water must be afforded 

 occasionally. 



Rhododendron (Azalea) indicum Withering: 

 A. E. R. No disease is present in the plant. 

 The trouble is the outcome of root-disturbance, 

 and is of frequent occurrence. 



Seakale Unhealthy : Seal-ale. The unsatisfac- 

 tory condition of the Seakale is not due to 

 either fungous or insects pests. 



Seaside Town: E. 0. B. The best deciduous 

 trees to plant along the streets of a southern 

 seaside town are the Tree of Heaven (Ailan- 

 thus glandulosa), the False Acacia (Robinia 

 pseudacacia), the Cornish Elm (Ulmus cornu- 

 biensis), and the Birch (Betula alba). Suit- 

 able evergreen trees include the Holly (Ilex 

 aquifolium, and its varieties), the evergreen 

 Oak (Quercus Ilex), the Cork Oak (Quercus 

 suber), the Austrian Pine (Pinus austriaca), 

 and Pinus Coulteri. The north screen could well 

 be planted with a few of the evergreen trees 

 named, especially the Hex and Holly, and any 

 of the following trees and shrubs : Lawson's 

 Cypress (Cupressus Lawsoniana), the Nootka 

 Sound Cypress (Cupressus nootkatensis), the 

 Western Arbor- Vitse (Thuya occidentalis), the 

 Box (Buxus sempervirens and B. balearica), the 

 scarlet Thorn (Crataegus Pyracantha), Furze 

 (Ulex europaeus and its varieties), Junipers 

 (Juniperus species), Myrtles (Myrtus species), 

 Griselinia littoralis, Phillyrsea media, P. an- 

 gustifolia, Cotoneaster microphylla, Euonymus 

 japonicus, and many kinds of Ivy (Hedera 

 Helix). But to plant a screen of shrubs which 

 will be a tasteful blending of the various forms 

 and flowers, and a pleasure to the public, in- 

 stead of the heterogenous muddles of a few 

 different shrubs usually seen in public places, 

 much more than a list of suitable species is 

 required. Before deciding on your selection, 

 it will be advisable to carefully consider the 

 soil and its treatment before planting, also the 

 present and future effect of the grouping of 

 the shrubs you employ. 



Soil Sterilisation : //. W. C. It is not ec'.sy 

 without suitable appliances to control the tem- 



perature in the process of soil sterilisation. 

 Probably the simplest method for you to try 

 is that which vou suggest, namely, to build up 

 a wood fire, about a large iron pot, or, better 

 still, to sling the pot over the fire. Then, 

 before lighting the wood, fill the pot with 

 thoroughly moistened soil, plunge the thermo- 

 meter attached to a stick nearly to the bottom 

 of the pot, which should not be covered. Light 

 the fire, and when the thermometer registers 

 200° F. rake away the fire, remove the ther- 

 mometer, put on the lid, and leave the soil to 

 cool. If you wish to use chemicals instead of 

 heat for sterilisation, the soil must be thor- 

 oughly moistened with toluol, and then spread 

 out in a fairly thin layer, and raked over from 

 time to time till the sterilising substance has 

 evaporated. In this connection you should 

 consult the article in our present issue, p. 113. 



Thyra Wood: //. Rabjohn. We are unable 

 to trace such a name as Thyra Wood. The 

 nearest approach to it that w T e can find is 

 " Tyrah," an Indian vernacular name ap- 

 plied to Bambusa khasiana. This is referred 

 to by Sir D. Brandis in Indian Trees, p. 668. 

 The word " Thura " is used in connection 

 with Euphorbia Nivulia in India. If you 

 could obtain a specimen of the wood, or better 

 still of the leaves and the flowers of the tree, 

 we should probably be able to identify it. 

 You should also give, if possible, the name of 

 the country from which the wood was ob- 

 tained. 



Winter Wash for Fruit Trees: A. S. The 



formula of your winter wash is the same as 

 that which was found in the Woburn experi- 

 ments most effective for the destruction of 

 scale, except that ^ lb. of lime was used instead 

 of £ lb. Probably, however, the reduction of 

 the lime improves the consistency of the wash, 

 and its benefit is questionable, because the sul- 

 phuric acid in the iron sulphate would combine 

 with it, converting it into inoperative sulphate 

 of lime (gypsum). The proper way of makin 

 the mixture is as follows : — Dissolve ^ lb. o 

 iron sulphate in boiling water, made up to 

 8 gallons vvlth cold water, and add to it milk 

 of lime, made by shaking i lb. of quicklime, 

 diluting it and straining the dilution. Then 

 add 5 pints of paraffin and 2 lbs. of caustic 

 soda, churning the mixture up thoroughly by 

 means of a large syringe, and making up to 

 10 gallons. This winter wash was recom- 

 mended as a general one, and not for scale 

 onlv, and ther* is probablv no better one for 

 the" destruction of the woolly aphis, American 

 blight, when the pest is established on large 

 trees. For its eradication on young trees pure 

 methylated spirit, applied with a small brush, 

 is a perfect specific. But so far as scale is con- 

 cerned, lime-sulphur alone has almost entirely- 

 superseded other washes in the United States, 

 where scale is verv much more common than 

 in this country. It is much less likely to do 

 harm to the 'bark of trees than the stron 

 solution of caustic soda, which you name, il 

 applied year after year, even if the mixture 

 you name has any such action. For example, 

 lime-sulphur would be beneficial where the 

 shoots of Plums and Apples are affected bj 

 brown rot or scab, and it is questionable 

 whether the other mixture would have an J 

 fungicidal action. A clean solution of lime- 

 sulphur, easy to spray, is now to be obtained o 

 Messrs. Walter Voss & Co., Mill wall, London, 

 showing 31° to 33° of density when 

 tested with the Baume hydrometer (equal to 

 1.2719° to 1.2946° as shown on the ordinary 

 hydrometer). The dilution of solutions oi 

 these strengths should be at the 

 10 gallons of water to 1 gallon of the solution. 

 But it is doubtful whether this wash woiiia 

 have much effect upon the woolly aphis- <~e " 



tainlv it would not be as effective in the ae- 



a combination oi 



It ™av be men- 



rate of 9 to 



struction of the pest as 

 paraffin and caustic soda 



may 



tioned that the use of iron sulphate m 



the 



mixture vou name is only that of an enu 

 tier to the paraffin. 



Communications Received. —A. K. T., XJ 

 the fact was announced in the last issue. )- 



C. F. B _Mrs. V. J. B. M G. R. S.^A. 



__J. H — F. H. N H. H. S Botanist 



9. A. (Thanks, 

 T A — R R — 



E ' ( Guildford 

 _A. G- 



__W. B. L._H. W. W._F. W. & Co._F. W. <V 

 _W, A. M.__W. H. A.— Polegate— B. G. W- 

 —J. D. M — A. G., Somerset_H. E — H. R-. % 



-A. P. R._H. H. R.__Anxious, Yorkshire-- 1 * jjjr g§ 

 (Many thanks ; the news had already reached us.; 



G. M. T- 



W. B.-j 



Holland 



