Practical Gardening

Star (Christchurch), Volume XLIV, Issue 62, 14 March 1931, Page 25 (Supplement)

Practical Gardening

Combridae,

TIMELY REMINDERS, j FIREBLIGHT. ITS IDENTIFICATION. Tn view of the serious outbreak of fireblight among our pear trees a further contribution to the various newspaper articles published upon it is subjoined. Samples of many and various sorts of fruit trees are being submitted to the local seedsmen and orcharists for identification of fire blight, and this is appreciated, as, unless thorough co-operation on the part of every pear tree grower is forthcoming, the position will be disastrous next spring. At present the disease is found only on the pear, and every pear tree should be carefully looked over, especially the tall large ones, and anything approaching the subjoined description should be submitted to the local Government inspector or a nurseryman, seedsman or the editor of this column. No one desires to cut a tree down needlessly. Only where fireblight is present will it have to be removed. Some years ago one of our leading orchardists stressed the point that Canterbury in general, and Chri'stchurch in particular, was not suited to growing apples for export trade, since the fruits did not colour well enough, but that it was an ideal province for pears. There are hundreds of pear trees in local gardens, and a number of orchards which would be lost if once fireblight got amongst them. Therefore this disease is a most serious one to Canterbury. I am indebted to Messrs Hesler and Whetzel in their “Manual of Fruit Diseases,” and to Dr G. H. Cunningham, B.Sc., in his excellent work on “Fungus Diseases of Fruit Trees in New Zealand,” for the information found hereunder: — In America by far the most destructive disease of some fruits is fireblight, where it not only attacks the pear, but affects the apple, apricot, Cherry, plum, prune and quince. It was first recorded and described in 1794 from the Hudson River highlands in New York State. For many years it was unknown on the Pacific Coast, but in 1900 it was described in California. In 1920 it was general all over the United States and in Southern Canada. Spreading in Auckland. In December of 1919 it was found in the Auckland province in widely separated areas. In the early part of 1920 Dr Cunningham relates that in personal investigations in the field he found it in Warkworth, Te Papa, Hamilton, Cambridge, Te Awamutu, Tauranga and Opotiki. In eighteen months it spread over a triangular area of country extending from Paparoa in the north to Te Awamutu in the south and Opotiki in the east, the return line being from Opotiki through Thames to Paparoa. In 1922 it was found in the Wanganui .district, and later in the same year yn the Wairarapa. Introduction a Mystery. Its introduction into New Zealand is a complete mystery, as also is the means whereby it jumped from the Auckland province to Wanganui. Its life history and its method of propagation are well known, and it has been isolated from specimens of apples, hawthorn, medlar, pear and quince. On fruit trees the first evidence of the attack is shown by the strange appearance of the blossoms, newly forming fruit, and the leaves surrounding the blossom. The wilting of the blossoms is always followed by the wilting of the leaves on the flowering spur, the vulnerable point of infection being the blossom, which, once infected, the disease travels down the flower stem or pedicle and into the shoot, and where the blossom is on a lateral the disease travels into this lateral and very quickly girdles it, thus cutting off its supply of sap. It dies, but retains its leaves most tenaciously. Of course they turn brown, and it is this

appearance of an affected tree which gives it the name of fire blight. On th# Hawthorn. The same evidence of scorched foliage leads to identification of the disease on the hawthorn, with this difference, that the hawthorn is never killed by the disease but continues an unfailing source of future infection. Where the blossom spurs are on larger limbs and

branches the disease spreads to them where it turns the bark a darker colour and the infected patch sinks lower than the surrounding tissue. This patch of infected limb or branch does not show cracks or markings across its area as in some rot and canker diseases, but later in the history of the complaint the area is separated from the surrounding tissue by a clearly defined crevice, which runs all round it.

When fruits are affected there is a soft rot very like other soft rots affecting some fruits, only in this case a number of globules of ooze are always apparent scattered over the affected surface. Adverting to the canker evidence; After infection has taken place the previous year, the springtime sees these cankers putting on a waterlogged appearance, and they exude a number of coloured drops of ooze which contain the bacteria for carrying on the complaint. The pathogene lives entirely within the tissue of its host, and it cannot live long in dead tissue. During the winter it carries over in the edges of the cankered areas, and in spring, as the watery appearance comes, it. extends into living tissue again, besides which the ooze containing the bacteria is forced out of the bark lenticels, and to which insects, bees and flies are attracted, hence the spread of the trouble to the flowers, tender shoots and any wounds the insects may alight upon. Death in a Few Weeks.

To quote Dr Cunningham: ** Some indication of the serious nature of this disease may be gained from the following particulars: In Tauranga early in 1920 I saw a block of ten acres of pears which had been practically killed outright in a few weeks, the remaining trees being damaged to such an extent as to render them worthless.” It has been proved by New Zealand bacteriological workers that the disease carries over in cankers on the hawthorn and El IS EfEJ®®!

“Glad,” St Albans, asks: Would you inform me of the best way to raise gladiolus from seed, when and how to sow seed and what care should be taken to get best results? I would like to know the same in regard to bulbous iris. The gladiolus produces seed readily and the seed germinates freely. Seed is sown as soon as ripe provided that it is not too late in the year. Ripe seed may be kept until spi'ing and sown in the open during September-October. The seedlings flower during the second season. If sowing is done thinly they may remain in the seed-bed until they dower. The seed-bed should be prepared with a fine tilth and, fow preference, in the vegetable garden, where the soil is well drained and well worked. Gladiolus prefer sunshine and the action of the weather about them. Care needed is regular hoeing and weeding during the growing period, with regular waterings during hot weather. There is no need to lift the first winter. Older bulbs are lifted each year. A large number of iris throw seed but it is almost always necessary to artificially place the pollen on the stigma lip. Seed may be sown in autumn if ripe in time, which is usually the case with the bulbous section. The ground must be well prepared, fairly rich and well manured. Sow seed either in seed pans or the open ground, the latter fc-r preference, as the seedlings are hardy. Often the seed is very irregular in coming up, so open ground sowing is best. In cases of this sort it is permissible to examine the seed to see if it is still good, but, generally speaking, it is a bad practice to poke about the seed-bed for signs of germination.

“ A.5.K.,” Addington, writes: I am sending a piece of a plant from our garden, name not known to me. We have two clumps of this flower. One has died, the other is dry and withered like the piece in the box. Could • you tell us what to do?

There is insufficient information to come to a decision about your plant, and your sample was not comprehensive enough. I suggest your plants have been in the same position for many years, and that they have got tired of growing. A number of plants in the herbaclous section (that is, those softstemed plants that die down each season) enjoy being lifted, divided, the soil turned over and renewed before they are put back. All garden plants are not like this, and herein lies the success or failure of many enthusiasts. It takes time to find out what various plants appreciate. “ Sandy.” City, writes:—l planted five or six hundred daffodil. bulbs last autumn. W'hen clearing up tlie ground T find they have nearly all rotted. Thov have been facing the north on a bank, and the ground is very sandy. -Has the place been too hot for them, or can you give me any reason for the rot? There are two probable causes. The first is that your bulbs may have been planted too shallow for your sunnv, dry bank. The second is that you may have bulb mite in the bed, or more likely In the bulbJ before they wefe planted. If the first IS the eaSe, plant the new lot five or Six Inches deep, giving the drills or trenches a dusting of bonedust before setting the bulbs in position. If it is the isecond. examine yoAir sound bulbs carefully for softness/ discolouration, or

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pear trees, and that the exudate of these cankers is sufficient to spoil hundreds of trees in one spring. This exudate is capable of retaining virulentbacillus for a very long time. Not only can flies and bees carry this organism, but sucking insects such as green and black aphis can carry it in their mouth and as they puncture young shoots and tissue the disease obtains a hold. Problem of Control. The question of control in New Zealand is a most important one, as we have legislature necessitating the reporting to our local orchard instructor of the first suspicion of the disease, and so anxious is each fruit district to keep clean that no effort is spared to clean up the place where the trouble is apparent. It is not hard to identify since the wilting .of the leaves themselves draws attention and added to them is always at this season the sunken area of the canker at the base of the infected shoot, spur or iateral. The only remedy is removal of the tree, and a most careful burning of every part. The disease carries over indefinitely on the hawthorn, which must be removed if immunity of the district is to be maintained. As the disease is in our district, a sharp look-out should be kept for-cank-ers on fruit trees, during this coming autumn, as well as wilting of foliage on hawthorn, and any noticed should be reported to come person who could advise. It must be remembered, of course, that accompanying the wilting .will always be the cankerous area at the base of the wilted branch or twig; without this the wilt may be caused by quite another thing than fireblight. It is to be hoped that there is none in any other part of the Dominion than where it is now recorded, but after America’s experience we shall be very fortunate if we can confine it to any definite area.

an unpleasant smell, planting them if clean in another part of the garden. If not clean, immerse them in a solution of quarter-pint formalin, 40 per cent strength to 10 gallons cold water for half an hour. Formalin may be obtained from your chemist. The infected ground should be given a spell from all bulbs for the next four or five years. “ Garden,” Burwood, writes:—Will some of your readers who are versed in the spraying of fruit trees please state lor general information the relative advantages of substituting soap spray for the more expensive chemicals generally used? In a well-known garden book I find eulogistic reference to a simple and inexpensive soap mixture. Growers in a large way are stated to haye kept their trees In healthy condition by soap spray alone. In these hard times one fannot afford even the few shillings for chemicals, but if suds be really efficacious, well, one can always make a raid on.the family tub! By the way, is St Mungo and washing soda detrimental to the trees? The plan recommended is to have the sud just to set to a jelly when cold, and to warm it well so that it will be thin for spraying. The value has gone out of the soap suds for spraying purposes after the clothes have been properly passed through them. The water is useful as a spray fluid only because of its added softness. I am not familiar with St Mungo, but if it is a washing powder or soap flake it should be useful in making a lather. Too much washing soda is harmful to foliage, especially young spring growth. I suggest further that to make a solution as referred to from your extract will be fairly expensive, since “ jellied soapy water” calls for a large proportion of soap. When going to so much trouble the book should have recommended the addition of kerosene in a correct pi*oportion and advised a dilution of strength. Then for some pests it would have been most effective. It must be pointed out, however, that neither suds nor kerosene will control codlin moth, pear slug, brown rot, black spot, shot-hole fungus, leaf rust, leaf scorch, pear leaf blister mite. San Jose scale, red mite, powdery mildew, white fly, die back or gumosis. Unfortunately we are faced with the necessity of buying spray fluids or losing our crops; but it is proved over and over again that where systematic and correct spray control is undertaken the cost spread over the year Is small and the return fully justifies the outlay. E.A.E., Ashburton, writes: T am layingout a garden here and I have a cold frame for protecting plants. I propose planting delphiniums, gallardias, Iceland poppies, antirrhinums. pansies, carnations and wallflowers. if seed of these were sown now would they survive the frosts with the aid of a cold frame and covering with scrim until ready to plant out? They would all stand fairly heavy frosts without damage Sown now the plant* Tfrould be a nice size by next Spring. The only frost damage likely would be a late frost In spring after the plants have made some young growth, but it would need to be exceptionnlly severe to damage them. You Would be quite safe, I think, in planting as you suggest.

CURRENT OPERATIONS. LILIES IN POTS. HINTS FOR ROSE-BUDDERS. Always do your work as quickly and cleanly as possible, so long as you secure yoar object. Never use a dull knife, nor muddle your work by rough lifting of the stock’s bark. Never let the buds dry up. Any after moisture that is supplied cannot replace the natural sap that grew there. To aid against this drying up, remove all foliage down to the short shank left for the better handling of the bud, directly you have cut the shoot from the tree. If the stick of buds is then put into water you save drying, and retain the sap. If your stocks do not lift well, give a good watering and try again in three or four dfiys. Never cut off growth from the stock just previous to inserting the bud, to make the operation more easy to get at. This checks the flow of sap for a time, just when the free flow is essen. tial. Do the necessary cutting at least a week previous to budding. Tie firmly, and be sure the “ seat ” or “ heel ” of the rose bud rests plumb down upon the wood of the stock. It is around this that the tie should be secure without undue constriction. Alwa} r s work the bud as near as you can upon the crown of roots with all dwarf stocks. Don’t let the point of your knife go into the wood beneath the bark when making a cut towards lifting the bark to receive the bud. So many are too heavy-handed here and cause much injury to the wood. Nor should the glutinous sap between wood and bark be disturbed or bruised any more than is absolutely necessary. Do not haste, but be sure that both bud and stock are in the best condition for the operation. This is of far more importance than the gain or loss of a week or so. Remember that the “ survival of the fittest ” may be applied here; also the benefits of selection when propagating, and take a little more care to help in this direction by always using the best buds from the best plants only. VIOLETS. Keep the surface of the bed hoed during the summer, and should the weather become dry, an occasional watering can be given. A sprinkling of nitrate of soda at the rate of one ounce to the square yard, either put on during rain or well watered in, will give the plants a fillip. Another similar dressing about a month later will help them wonderfully, and will assist them to make strong plants that will give abundance of long-stemmed blooms. Runners should be kept cut off the plants throughout the summer, so as to assist the plants to make a good strong natural crown which will produce the best flowers. Red spider is the worst enemy of violets, and attacks them during the heat of summer. Should this appear, give the plants a spraying with lime sulphur at the proportions of 1—125. <

HOW TO GROW LILIUMS IN ROTS. Of the many bulbs which do well in pots for the decoration, of the greenhouse or verandah, none surpasses the liliums. To do them well, they should be potted or planted as soon as obtainable, and. it is a mistake to leave the procuring of them or to consider that they can be stored like daffodils. They should not he out of the ground any longer than possible, and when growing in pots they should be potted as soon as possible. Although the following remarks apply most particularly to the growing in pots, they will also be found to contain “useful information regarding the growing in the open ground.

A glance at Figs. 1 and 2 will show that the bulb in the first pot is higher than that in the second. The distinction is made because some species of lilium, beside sending out roots from the “base of the bulb, also send some from the stem, and to leave room for a subsequent top-dressing of soil to accommodate these stem roots, the bulb is put nearer the bottom of the pot. A compost that will suit all the species may be made up with two parts of fibrous loam, one part leaf-mould, or peat, half a part of well-decayed, flaky manure, or a little hop manure, and sand to make the mixture por<Tus. (five good drainage, and over the crocks put a layer of the-rougher parts of the compost. For L. testaceum and L. chalcedonicum, half fill the pot with the finer soil, and then put the bulb in place, having first spread a thin layer of. sand for its base to rest on. Fill up with the compost, and give another little dash of sand on the crown. The method is shown in Fig. 1.

Fig. 2 deals with the stem-rooting lilies. The process is the same as for the others, but the bulb is placed lower in the pot. Later on, when the stem roots are about £in long (see A in Fig. 3), a top-dressing of good, rich compost is added (as at B). In this top-dressing it will be advisable to mix a little of one of the standard fertilisers.

If the compost is reasonably moist when the bulbs are potted, no water should 'be needed until growth starts. Stand the pots in a cold frame, or in a cupboard, or under the staging of a* cool greenhouse. At this season it will not be long before signs of growth -will appear, after which the plant can be brought into the full light, and be given as much air as possible.

As growth becomes more vigorous, give water freely, and also an occasional application of liquid manure. At the base of the bulb, and in some varieties up the stem in the axils of the leaves, small offsets will often be found (see Figs. 4 and 0). These may bo removed, when the plant is at rest, und ‘ sown” in a pan of light, sandy soil (Eig. i ), which should be placed in a frame. Another method of increasing the stock is by planting scales (Fi" s)° which should be inserted— as shown in s —upright, and not more than half covered with soil. Small bulbs will develop in tunc, which will grow into flowering eyes. Both these methods of propagation require patience, for tile rale of growth is slow, and they require severs l years to form flowering bulbs. Ihe size of the pot must be regulated by the size of the bulb. A Sin pot will do for an average bulb, while for an extra large one the size may run up to Sin. Liliums do best when their stems are protected from the sun, but Sf &t"£s a"* ,0t thcm plentjj

SPINACH BEET. '1 o those with a limited garden accommodation, aind who require a vegetable to come in when other sorts are “ off ” or not ready, there is nothing that can equal spinach beet or perpetual spinach, both of which are one and the same thing. Spinach beet will yield pickings over a long period—in fact, it can be considered valuable all the j'ear round. Seeds sown will produce plants that will give a picking towards the end of summer, and will continue throughout the autumn and winter. The ground should be well

prepared by being deeply dug and well manured. 1 he. seed should be sown in drills, allowing two feet between the drills, although in most cases one row would be sufficient. The plants, when up, should be thinned to a foot apart. This plant is a native of the sea coast, and if a light dressing of common salt is applied to the ground it can either be dug in before the seed is sown or put on after the plants are a fair si 29, or at both periods. It will cause the plants to be much more vigorous, and to give larger and more tender leaves. One ounce of salt) to a yard of drill will be sufficient at each application.