6o 



IRISH GARDENING. 



Cclcrv Leaf Spot. 



A l-'iNiiMin HisKASK iKANSMi 1 I i;i> i!V Si:i:n. 



IN .motliiT part of this issiio will he roiiiul a iioti- 

 doaliny^ witii tlio antlir.icnose disease of ilu- luaii 

 which is transmitted by the seed. In tliis loii- 

 tu'clioii it may not be out of place to call attention to 

 another case of disease transmission by means of sei-il 

 whicli lias only quite recently been established. 



Durinij the last few years we have received a 

 number of complaints rcyfariiini^ the celery leaf spot 

 disease caused by the fungus, Sc/>/vria /\ frosciini Desm. 

 var. Apii Briosi et Cavara. An important article on 

 this disease has just been published by Klebahn,* in 

 which he shows among-st ot'.ier things that the fiucli- 

 tications of the fungus are to be found on the " seed" 

 (botanically the " mericarp") of the celery plant, in one 

 case as much as seven per cent, of the " seed " being 

 thus affected. It would be well if gardeners who have 

 been troubled with this pest would examine their seed 

 very carefully before sowing it, or perhaps better still, 

 seiul up a convi-nient sample of it for expert examina- 

 tion. G. H. P. 



• H. Klebahn — "Krankheiten desSelleries"—Zeitsch. f. 

 Pflanzenkrankheiten, Bd. xx. Heft. I. Jan. 1910. 



The Chrysanthemum. 



IV. — Treatment of Rooted Cuttings. 



MUCH care and constant attention is necessar}' to 

 the successful growing of chrysanthemums. 

 Each plant must be looked at at least once a 

 ila\-. Watering must not be done indiscriminately, but 

 in proportion to each plant's needs, and not after three 

 o'clock in the afternoon. To secure healthy and forward 

 plants avoid all checks. Be on the look out for frosts, 

 and if there is sign of heavy frost cover the glass with 

 mats. Watch for slugs, and have the ashes upon which 

 the pots stand liberally covered with soot ; but even so, 

 a careful watch must be kept. In wet weather, when 

 the frames have been kept close, signs of mildew often 

 appear. This must be seen to at once. Remove the 

 lights as soon as possible, and dust well both sides of 

 the leaves with flower of sulphur. This trouble is more 

 often experienced in striking cuttings ; treat in the same 

 way. Another thing to be on the look out for is green- 

 fly. These little pests will be found in the unfolding 

 leaves, and will rapidly spread unless got rid of by 

 fumigating. .Another eff'ective method is tobacco dust 

 sprinkled over the affected parts at night, and syringed 

 off in the morning. 



Rust or mould is a fungus due to overcrowding. It 

 comes mostly in wet seasons, and appear as black spots 

 on the leaves, spreading rapidly. The only preventative 

 and cure is to give the plants plenty of air and room- 

 The young plants should be kept as hardy as possible, 

 and during the day-time, when there is no rain and it is 

 not too cold, the lights should be taken quite off, so that 

 the plants may get plenty of air. Those at the back of 

 frame should be raised as near the glass as possible. 



It is \ciy dis.ippointing when ,'i promising young 

 pl.inl breaks into bud (this is because the cutting was 

 t.iken from the stem of the plant). This bud must be 

 |>inched out ;il oni-c. Surli ;i pl.int would be of no use 

 fov exhibition put|iosi's, .as llictf can he no nu'.ins of 

 t iming the buds. 



I'l.mts rooted at beginning of year should be ready 

 fov pinching by now, and will be about six inches high. 

 This method is only used for plants required for decora- 

 tive purposes. In pinching, the growing point is nipped 

 out, and three side shoots allowed to grow. Early in 

 this month the plants will be ready for shifting into 

 six-inch pots. The soil may be heavier and coarser 

 than in the last poltins^, .and should be chiefly composed 

 of i::ood fibrous loam, four parts, one part leaf mould, 

 one part mortar rubbish, one part rotten manure, and 

 one part wood ash. 



After re-potting it is better not to water for a few 

 days till the plant is established, but sprinkle the leaves 

 of the plants once or twice during the day. Some 

 growers shade their plants during this period. It is 

 any waj- advisable to keep them close for a day or so 

 after the shift. 



c^* e^* t^' 



Nitrification in Soils.— One of the most important, 

 if not the most important factor in maintaining fertility in 

 soils is, that the natural process of nitrification is 

 encouraged by the cultivator. The formation of 

 nitrates is brought about through the vital action of 

 particubir kinds of germs that alter the ammonia com- 

 pounds produced by the decomposition of organic 

 matter present in the soil. How can the gardener 

 CTicourage nitrification ? He can encourage it by 

 making the soil conditions as favourable as possible to 

 the vigorous working of the nitrifj'ing bacteria. F"irst. 

 these living germs require food. .\s their chief food is 

 derived from organic matter, the soil must contain a 

 sufficiency of humus. Then the soil must be kept moist, 

 but not in the very least degree water-logged, because 

 as a third condition the soil must be kept well aerated, 

 as these nitrifying organisms must he well supplied with 

 air containing oxygen, seeing that the process of nitri- 

 fication is essentially a process of oxidation. Drainage 

 and persistent hoeing are, therefore, primary conditions 

 of success, A still further condition is the presence of 

 some alkali to neutralise the nitric acid formed by the 

 bacteria, and lime is the best and most convenient 

 substance to appl}'. Lastly, as a summer tempera- 

 ture is most favouring to the growth and develop- 

 ment of these nitrifying bacteria, gardeners should 

 endeavour to see to it that all these soil conditions 

 obtain throughout the whole growing season. F"ur- 

 thermore, it is well to remember that the conditions 

 that favour nitrification are precisely the conditions 

 that are best for the health and development of 

 crops. 



Hedges of Sweet Briar. - Can anything be prettier 

 than a hedge of sweet briar in flower or fruit ? To make 

 one use the Penzance briar and plant one foot apart in 

 well-trenched and manure ground. Prune hard back 

 the first year. They will afterwards grow five or six 

 feet high. 



