THE GARDEN.

Manawatu Standard, Volume LII, Issue 4, 4 December 1931, Page 4

THE GARDEN.

Note* are published undor this boadi are invited to send in questions relating advice; answers will be published with i

RED DELPHINIUMS,

Hearing that red delphiniums had been raised in Holland, we wrote to the raiser, Mr B. Ruys, for confirmation of the report and have received a very interesting letter from him not only confirming the information, but also giving some interesting details. Ho says:—“l I first began to try for red delphiniums in 1902, but had no luck at all. However, in 1917 I got an assistant who had 'some experience of hybridising, but ■again our longed for plant did no come to light. The hybridising was kept going until 1929, when we got a form that was evidently a cross between D. Nudicale •and D. E’latum not only in the form ‘and growth, but in the colour of the flowers, too. Whop it bloomed the flowers were a dirty purple and the plant of no decorative value. If the laws of Wendel had not given us cause ' for hope that this plant might give us a good red delphinium, we might have thrown it away; it was kept and wo carefully harvested every seed. In the 6pring of 1930 we had about two hundred seedlings, and nearly all of them began to flower in July and August of the same year, and four of them had j flowers of a good red colour. One in j particular was a most brilliant red and 1 the flowers were of good size and form and it grew three and a half feet high. Last spring every grain of seed was sown and from the plants raised, which we called No. 1, about, twenty-five have good red flowers. These began to bloom in July and August, and are still in full bloom. The four red flowered plants ■which flowered for the first time last year were transplanted last spring as well as the original plant, which was divided into four. This operation showed that the roots were intermediate in character between the two parents; they were not so bulbous as Mudicale or so fibrous as Elation, and, what is of great importance, all' the parents are true perennials. A very remarkable characteristic of this new race is that all the plants of the two generations began to flower about the middle of May in the

ing, and readers interested in pardoning to matters upon which they wish expert the weekly notes.

open ground, and they have flowered on until the end of July and one plant is now (August) producing secondary spikes. This is a great advantage as they not only flower a month earlier than the ordinary elatum hybrids, but the flowering period is much longer. I have only mentioned the red varieties of these crosses, but we have found others of great decorative value, ranging in colour from pink to dark violet, and some with a very conspicuous eye or bee. Of course they are all being tested and the best forms will be propagated, but it will be some years before they can be offered to the public.” We may state here that Mr Ruys is a noted raiser of hybrid delphiniums and was the man who put the white variety Moerheimii on the market and which is now grown all over the world.. SOIL STERILISATION.

Dr W. F. Bewley has issued a booklet on his observations about soil sterilisation. He has not gone into the reasons for sterilising, but deals more with the methods where the work can be done and the most economical way in which to apply it. In essentials, the question turns on the agent to be used in sterilising, and here he discusses the two main channels, in one of which are found chemical germicides and in the other heat. Heat is divided into two sub-sections, dry and wet, that is baking or steaming. After reading the brochure one is not left in doubt that beat as a sterilising agent has advantages over all other ways and means at present available. The choice of agents will depend on circumstances, and where only a small quantity of soil lias to be treated amateur gardeners will probably like to use a chemical solution. The main objection to the use of any liquid steriliser is that many soils cannot be broken up small enough to allow the solution to reach every part. This is of less account in the case of light powdery soils than it is with heavy sticky clay soils. Dr Bewley considers that'it is equally important to steri-

lise the leaf mould and manure that is added to the soil as it is to sterilise the soil itself. On reading the article we are inclined to think that it would be better to do the two together than to do each separately, but if the two are done separately a liquid steriliser could bo used for the leaf-mould or manure and would' be quite as efficient. The cost, of a steam sterilising plant would prevent the ordinary amateur from going in for the work, but the doctor thinks that when the advantages of steam sterilising becomes better known, and its worth appreciated, there will be plants available for the purpose. He makes it very clear that the work has only to be done once in four years, that is, as long as a proper rotation of crops is gone in for. Formaldehyde is the most efficient, but did not quite reach the yield given from the steam process. Carbolic acid gave fairly good results, but, as he points out, chemicals have to bo used every year, whereas steaming on the four years principle is bv far the clienper ; but here .again a small quantity of soil can be treated with formaldehyde at a very low cost. Where eelworm is the pest to be destroyed, the soil should be sterilised two spits deep, ns the worm is often found below a depth of eighteen inches. It may be necessary to remind readers that if they are sterilising soil for potting or seed raising it is necessary to leave it for several weeks before it is used. One thing very noticeable is that he does not refer to carbon bisulphide as a sterilising agent, probably because it is not a fungicide, but is fatal to soil organisms. The number of the Bulletin is 22, Practical Soil Sterilisation. IRIS SUSIANA. •

In answer to a correspondent who wanted to know how to grow Iris Susiana we may say that, having no success with several batches of this beautiful flower, we gave it up as a bad job, but coming across a gardener who lias grown it successfully for three or four . years we are giving his methods. When the plants have finished flowering, and have died partly down, he covers them in the place where they are growing with bell glasses which are made of the large globes that were used for street lightting by gas a few years ago. He got some of these for a few pence eacli

and cut them in lralf, and over the hole he places a sheet of glass cut from plate glass and which, being heavy, keeps itself in place. This covering is left on until the early spring when it is taken away and the irises are allowed to grow. He also had some old large battery, jars which ho used for the same purpose. The soil must be kept dry during the winter and all weeds and slugs must be kept away from the plants You may succeed by adopting the above plan, but at the same time we know of many gardeners who have tried various methods with these beautiful flowers and have failed. One thing is essential and that is that the soil should be dry and well drained and that it should contain a certain amount of fine gravel or grit. It does not matter if it is fairly rich land as long as the water gets away from it quickly. TRIALS OF RASPBERRIES. The Gardeners’ Chronicle says that some fifty varieties of raspberries are being tried out at Wisley in England and the results will be of considerable interest to both commercial and home gardeners here. “Undoubtedly the most satisfactory raspberries in the trial are Lloyd George, Red Cross and Pylie’s Royal and these may. be taken as standards for comparison with the other varieties. Lloyd George is fairly well known. Frequent replanting of this variety seems desirable as the new growths need severe and constant regulation as they tend to smother the fruiting canes. *As a market variety and for jam making and bottling it is always in demand. The fruits are of firm texture and good appearance conical in shape and large with a subacid flavour. It gives the earliest picking of berries with Red Cross a good second. Red Cross is one of the heaviest croppers in the trial and, although not so vigorous in cane production as Lloyd George, it retains its vitality longer.' The fruits are rather dull in colour for market work, but are of first rate quality, being large and conical in shape, of firm texture, sweet in flavour and the core leaves them easily. This can be described us the most promising of the modern varieties. Py.ne’s Royal requires generous treatment and is then unsurpassed by any variety. It is probably the finest raspberry tor garden culture and when well grown produces plenty of strong erect canes and a large crop of fine berries, conical in sha |>e and of a rick flavour. It is a splendid dessert fruit and ideal for marketing in punnets. A good variety for home garden is Lynn’s Superb, but it’s fruits are too soft for market purposes. At Wisley it is strong and healthy in growth. One of the best known varieties here is Red Antwerp or Red Belgian, the latter being the name it was first imported under. It is a long way down in the list as it is said to be lacking in quality and size of its fruits. Superlative is another variety that is largely grown here, and although it is still a favourite in some places, it has lost vigour and has fallen off badly in cropping and quality so that when compared with the more modern varieties it falls far short of being first class. In the account of the trials mentioned many other varieties are mentioned and some of them are old and some fairly modern, but for one reason or another none of them has received many marks. One variety called Brockett Hall, as grown at the trials, showed two distinct types, one very like Lloyd George, and being like that variety perpetual fruiting, while the other type suggests Baumforths Seedling. Both types are cropping heavily and they show distinctly promising qualities. Lord Lambourne is a yellow fruited counterpart of Lloyd George, both in size of fruit, the large conical berries being amber coloured, and sweetly flavoured. Norfolk Giant is the latest ripening raspberry in the trials and as a late variety would bo worth growing.” QUESTION. “Zinnia” says: “1 have always admired the giant zinnias both in gardens aud at the local show and have tried to grow them, but have never had the luck to get those fine large blooms that one so often sees. Are they special varieties and how are they grown ? A few hints would be apjpreciated.” Zinnias are grown from seed which should be sown where the plants are to flower to obtain the best results. They can be transplanted, but are best when grown in situ and thinned out. Seed can be sown now in rows about eighteen inches wide and when, the plants come up they should be thinned to this distance apart. It is better to make a special bed for them by digging deeply and adding some manure to the lower spits. Do not leave it - n patches, but mix it thoroughly with the subsoil. When the. bed is finished give the surface a dressing of lime and work this in; then sow the seed. The strain that gives the largest flowers is that called giant dahlia flowered. As soon, as the young plants can bo handled, thin them out and keep the surfaces of the bed well worked, but do not us© wator until th© buds are ready to be forced. Remove some of the buds and allow each plant to carry four or five. The plants will want careful staking. About a month before the show for which tile floners are required begin giving weak liquid manure in which some soot has been dissolved in the usual way.

THE VEGETABLE GARDEN. The rain has done a lot of good Lo vegetable gardens, especially where the soil has been well worked, and as long as it can be well cultivated there will be no need to fear loss of growth. Tomatoes have made excellent growth and must have the side shoots nipped out and the main stems tied up to their stakes. This tie should not be too tight; room must be allowed for growth. As soon as the first bunch of fruit has set the plants should be sprayed with Bordeaux mixture, using the summer formula. Prepare the ground now for planting out winter cabbages and broccoli. The main thing is to get this crop in early so that it makes good growth before the diamond-backed moth gets to work on them. In connection with the control of this moth, a correspondent says that he had good results from using weak disinfectant as a spray last season, but he wishes to try it out agftin bofor© recommending it to anyone else. He used a teaspoon to a gallon of water. Prepare trenches for planting out celery by digging a drain and breaking up the lower soil and putting six inches or so’ of manure along the bottom. The width will depend on whether two rows or one are to be grown - , if two, the trench should be about eighteen inches wide; for a single row ten to twelve inches is quite wide enough. Prick the celery plants out into a box where they can be lifted with a good ball of earth, and keep the plants well watered.