422 



THE GARDENERS' CHRONICLE. 



[June 22, 1912. 



-to 



Asters : G. S. The Asters were killed by the 

 fungus Thielavia basicola. Next season water 

 the soil about three weeks before planting with 

 a solution of formalin, using one pint in two 

 gallons of water. 



Blue Hydrangeas: B. M. W. There are 

 several methods of inducing plants of Hydran- 

 gea hortensis to produce blue flowers. In 

 Holler's Deutsche Gartner -Zeitung (No. 23, 

 1911), Mr. W. Titze recorded that he obtained 

 blue Hydrangeas by watering the plants twice 

 weekly with a solution of ammonia alum 

 (i ounce to 1 gallon of water). It is desirable 

 to water with this solution in the autumn 

 until the plants pass into their resting stage. 

 During their flowering period the plants should 

 not be grown in the full sun, or the blue colour 

 will become blotchy. Other cultivators have ob* 

 tained similar results by the use of such sub- 

 stances as alum, iron, and elate chippings mixed 

 with the soil. One grower records that he has ob- 

 tained blue Hydrangeas by laying the mowings 

 from lawns around the plants. In some gardens 

 Hydrangea hortensis will produce blue flowers 

 one year and flowers of the normal pink colour 

 the next ; or flowers of both colours will appear 

 on the same plant. This often happens in 

 the open when the plants have been top- 

 dressed with leaf-mould. 



Book : Arboretum. Pictorial Practical Tree 

 and Shrub Culture, by Walter P. Wright and 

 W. Dallimore, price Is. 2£d., free by post, from 

 our Publishing Department. 



Cucumbeh Leaves : M. M. The Cucumber 

 plants are affected with the Melon-spot mould 

 or blotch (Cercospora melonis). At an 

 early stage, spraying with Bordeaux mixture 

 may do some good, but it is not generally 

 very effective. Any diseased leaves detected 

 should be burnt. A mixture of carbolic acid and 

 water in saucers placed in Cucumber houses 

 has been stated to check the spread of the 

 disease (see Gardeners 9 Chronicle, April 15, 

 1905, page 235, and June 23, 1906, page 411). 



Curled Rose Leaves : P. S., Derby. See reply 

 to Subscriber in the last issue, p. 402. 



Diseased Pears : W. C. Diplosis pyrivora (the 

 Pear midge) is the name of the pest which has 

 caused the injury to the young Pears. It is 

 very difficult to check the ravages of this 

 insect. The only practical means of keeping 

 the pest under control is to collect and burn 

 all infested fruit before the imprisoned grubs 



escap 



e. 



Gardening in India: J. G., Ltd. 

 you refer to was published in 

 Chronicle, February 10 last, page 



The article 



Gardeners 9 

 82. 



Grapes: T. J. H. The brown marks on the 

 berries are caused by rubbing; probably when 

 thinning the berries. — H. W. The berries 

 show a slight trace of spot disease, and the 

 bunches should be sprayed with liver of sul- 

 phur, at the strength of £ ounce in 2 gallons 

 of water. The rusty appearance of some 

 of the berries is caused by rubbing during 

 thinning. Liver of sulphur will cause white 

 paint to turn a black colour, and care should 

 be taken to prevent the specific wetting the 

 woodwork of the vinery. — Header. Spray the 

 berries every other day with liver of sulphur, 

 using 1 ounce in 3 gallons of water. 



Insects Affecting Silver Fir: A. M. The 

 pest infesting the bark of the Silver Fir is 

 Chermes piceae, one of the aphides peculiar to 

 Conifers. If you desire to use the insecticide 

 referred to in your communication, or any 

 other preparation at this season, we would 

 advise you to apply it with a stiff brush to the 

 trunks and main branches. Spraying would 

 cause injury to the tender growths. 



Iris Diseased: J. F., Albury. The unhealthy 

 appearance of the Iris plants is caused by a 

 bacterial disease. Dress the soil with super- 

 phosphate of lime. Ordinary lime favours the 



disease. 



Lime Foliage with Reddish Outgrowths : 

 A. K. T. The outgrowths are galls, caused 

 by Eriophyes tilise. The galls occur only on 

 the upper surface of the leaves, and vary in 



colour. They are known as " Nail-galls," 

 from their appearance resembling a number of 

 tacks appearing through the upper surface of 

 the leaf. 



Names of Plants : Weeds. 1, Spergula arvensis ; 

 2, Polygonum sp. ; 3, Geranium Robertianum ; 



4, Ranunculus asiaticus var. flore pleno. — 

 G. A., Cornwall. Ornithogalum arabicum. — 

 Puzzled. ^ Carnation Cecilia. — Dublin. 1, 

 Abutilon vitifolium; 2, Cistus laurifolius; 3, 

 Phlomis f ruticosa ; 4, Scilla peruviana ; 5, 

 Polygonum Baldschuanicum ; 6, Veronica 

 austriaca var. prenja. — C. E. T. Phacelia 

 tanacetifolia. — W. J. D. 1, Spiraea, probably 



5. Thunbergii ; 2, Olearia Haastii ; 3, Spiraea 

 japonica; 4, cannot name without flowers; 5, 

 Cerastium Biebersteinii ; 6, Nepeta Mussinii ; 

 7, not found ; 8, not recognised ; 9, Rose Ard's 

 Pillar. — Alpine, Herts. 1, Draba grandiflora; 

 2, Acanthopanax vicinif olia ; 3, Vaccinium 

 corymbosum; 4, Dianthus plumarius var.; 5, 

 Erodium macrodenum ; 6. Dianthus arenarius ; 

 7, D. monspessulanus ; 8, Saxif raga Hostii. — 

 G. K. Phacelia campanularia. — R. T. 1, 

 Ornithocephalus grandiflorus ; 2, Cirrhopetalum 

 picturatum ; 3, Stelis ophioglossoides ,• 4, Odon- 

 toglossum blandum. — T. T. 1, Pteris hastata ; 

 2, Adiantum caudatum; 3, Cheilanthes lendi- 

 fera. — Foreman. 1, Promenaea stapelioides ; 2, 

 P. xanthina ; 3, Oncidium pubes ; 4, MaxiL 

 laria tenuifolia ; 5, Catasetum maculatum ; 6, 

 Cochlioda vulcanica. — H. L. W. It is impos- 

 sible to name such a poor and completely 

 shattered flower. Send better specimens, 

 together with a little growth. 



Peach Leaves: A. S. R. and H. A. T. The 



Peach trees are attacked by the Shot-hole 

 fungus (Cercospora circumscissa). Spray with 

 the ammoniacal solution of copper carbonate, * 

 just as the leaves are expanding, and repeat 

 the operation at intervals. A correspondent, 

 writing in our pages for October 14, 1905, 

 p. 282, stated that he had used Campbell's 

 sulphur vaporiser with good results. 



Pelargonium: L. L. The plants are not 

 diseased. The change of colour in the leaves 

 is due to some check. Excessive moisture at 

 the roots followed by a period of dryness will 

 cause them to change colour. Generally the 

 plants grow out of condition when bedded 

 out, and usually flower freely in consequence, 

 although the blooms are not so fine. 



Propagating Carnations: Carnation Cutting. 

 The propagation of tree Carnations is best car- 

 ried out between the months of December and 

 March, when cuttings strike readily on a very 

 mild hotbed, or in any house which has a 

 temperature of between* 50° and 60° and not 

 too dry an atmosphere. The rooting material 

 should be of a very porous nature, such 

 as a mixture of loam, sand, and finely- 

 broken crocks. Where large numbers are to 

 be rooted the cuttings may be dibbled into 

 shallow boxes, or into a specially-prepared bed 

 in a house such as described above. The best 

 cuttings are the young wiry shoots that push 

 out from the axils of the leaves during the 

 winter months. Strong flowering stems might 

 produce roots if cut below a joint, but this is a 

 slow method, and the resultant plants are often 

 unsatisfactory. 



Puddling Ponds : A. U. C. It is not generally 

 necessary to mix straw with the clay used for 

 puddling. If it is impossible to keep the pond 

 staunch with clay puddling, it will be neces- 

 sary to use a layer of concrete. This is the 

 more expensive method, but it lasts a very 

 long time. The clay for puddling should 

 be well worked before being used, so as 

 to make it adhesive. After the clay has been 

 thoroughly beaten against the bottom and sides 

 of the pond, it should not be exposed to the 

 drving influence of the air longer than can be 

 helped. 



Rhododendrons : H. H. R. The violet-coloured 

 blooms are from shoots of the stock, and these 

 must be removed. Pull the sucker growths 

 sideways with a sharp jerk, when most of them 

 will break clean off at the base. If this is 

 not effective, they should be cut off under- 

 ground with a knife or a sharp spade, cutting 

 them as close to the stem as possible. 



Rose Growths: A. C. We are inclined to the 

 opinion that your Rose shoots have been eaten 

 by rabbits, but this is one of the instances 

 w r here it is only the man on the spot who can 

 speak with any degree of certainty. We notice 

 that your Rosary is enclosed by wire -netting, 

 but we have often seen rabbits climb netting 

 3 feet in height, and also a rigid wire fence 

 2 feet 6 inches high. 



Rose Rust or Orange Fungus : Ranker. The 

 plants are infested with the rust fungus 

 (Phragmidium subcorticatum) . All fallen leaves 

 should be collected carefully and burnt, and 

 the plants should be sprayed with copper sul- 



f»hate in the winter. If the patches of orange 

 ungus appear on parts that can be readily re- 

 moved, they should be cut off and burnt. 

 Where this is impracticable the part diseased 

 should be rubbed over with a tuft of cotton- 

 wool dipped in methylated spirit. 



Scale on Apple : H. W. S. The insect is 

 one of the soft, brown scales, Lecanium gene- 

 vense. It attacks a number of different kinds 

 of trees, but is usually most abundant and de- 

 structive to the Hawthorn. It is a single- 

 brooded insect and passes the winter in the 

 larval stage, when it is minute and difficult to 

 detect. We would advise you to spray the 

 trees in winter with the M Woburn wash," 

 made up as follows : — Copper sulphate 1£ lb., 

 lime £ lb., paraffin 5 pints, caustic soda 2 lbs., 

 and water 10 gallons. 



Tomatos: B. P. The plants have received too 

 much water at the roots. For a time use a 

 little potash manure in plaee of the liquid. 



Tomatos Diseased: G. H. The plants are 

 attacked by the Tomato leaf-mould (Clado- 

 sporium fulvum). If fruits are not present, 

 spray the plants with the Bordeaux Mixture, 

 and repeat the spraying at short intervals. 

 Where the fruits are present, employ liver of 

 sulphur instead. See reply to P. I. in the last 

 issue, p. 402. 



Twin Roses: A. A. P. Your specimen of two 

 Roses on the same stalk is interesting but not 

 uncommon. It results from an abnormal de- 

 velopment of the apical bud. 



Unfruitful Canadian Apple Trees: A. B., 

 Bedford. As your trees of the variety 

 Northern Spy, which were imported from 

 Canada six years ago, and which are making 

 satisfactory growth, have not yet shown signs 

 of flowering, it is more probable that they 

 are worked on the crab stock. If this surmise 

 is correct, you may expect to see fruit-buds 

 within the next two or three years. Apples 

 which are grafted on the Crab stock are 

 much slower in coming into bearing than those 

 on the Paradise stock, but they are longer 

 lived. If you will send specimens of your 

 Raspberry canes which are dying w T e will en- 

 deavour to assist you. 



Vine Leaves : E. S., Dorset. There is no disease 

 present on the portion of vine received, but the 

 foliage is scorched. Ventilate the house early, 

 and keep the atmosphere rather dry. 



Vines : H. H. The sap-warts on the under-sides 

 of the leaves are the result of extreme condi- 

 tions in the atmosphere of the house, such as 

 a want of proper balance between the tem- 

 perature and the amount of atmospheric mois- 

 ture in it, or of unusually stimulating influ- 

 ences which have caused the epidermis of the 

 leaves to become ruptured. Pay special atten- 

 tion to ventilation, and keep the house drier. 



Violas Diseased : C. H. P. The plants have 

 been destroyed by eelworm, whicn is a verv 

 difficult pest to eradicate, insecticides being of 

 little avail. Burn all affected plants, remove 

 the soil in which they have been grown, and 

 either sterilise it by baking, or bury it in some 

 out-of-the-way part of the garden. 



Water Supply: Aquaticus. If the bottom of 

 the pond is rendered perfectly water-tight by 

 puddling it with clay the supply of water you 

 indicate would be sufficient to counterbalance 

 the loss by evaporation and to gently circulate 

 the water. 



Communications Received — T. M._E. W. Library— 



M. M., Rothesay_Ij. T, P Mushroom—Dublin--^^- 



-M. A. J.__A. B. H._H. S. E.-JD. <fc W. C.— R. E. W.-. 



8abor_ J. E A. C.—H. A .—Foliage— J. V. & Sons-H. b* 



~C. E. W.—E. G. H._R. P. B A. H. B.— Arboretum - 



A. V. C._ T. B._S. & Sons— C. R.—H. R. V-- A £' t 

 A. P._0. J. L._J. G. W._W. B._J. H. M.__ F. W. J- 



