GARDENERS’ QUERIES

Press, Volume CIII, Issue 30603, 20 November 1964, Page 6

GARDENERS’ QUERIES

Cherry Tr«« Suckers Could you please tell me what is wrong with my flowering cherry, J. H. Veitch, which I have had for three years? It is about four feet high but has only four branches which bear the true Rowers and bronze leaf, the others having green leaves and miserable single white flowers. Last year unfortunately most of the garden was affected by spray drifting across from the neighbouring farm. They were spraying hemlock. My cherry did not flower much at all. Would It be the spray that has caused the trouble, or is it the tree itself that is no good? A.L. (Kaiapoi). The cherry. J. H. Veitch, is a grafted variety and your tree has evidently produced suckers which seem to have become dominant as is usually the case when they are allowed to grow away unchecked. All branches bearing green leaves and single flowers should be cut out completely as flush as possible with the trunk from which they arise. Retain all wood carrying double pink flowers and bronze foliage, characteristic of the variety J. H. Veitch. This job should be done now and all cuts sealed immediately. Although the spray drift would undoubtedly cause damage, this does not seem apparent from your letter as symptoms include bleaching, distortion or death of leaves. Bark Ringing It has been suggested to me that the bark ringing of my apple trees will counteract the strong growth that they are making at the expense of fruit. Is this correct, and if so, how and when should It be done? S.T. (Christchurch). Yes, marking ringing is quite often used to restore balance between growth and fruit production. On big trees where growth is generally excessive two half-circles of bark about I to i inch in width; and two to three inches apart, are removed with a sharp knife on opposite sides of the trunk a short distance below the crotch. A complete ring i to (in wide can be made on smaller trees. Where unbalanced growth occurs, a half ring on the vigorously growing side will assist in restoring the balance. All cuts should be sealed directly after completion of the operation; tape as a proprietary sealant can be used. Immediately before, during or after flowering are considered the best times for bark ringing. Rust On Roses Could you please tell me the reason for the unhealthy appearance of the enclosed specimens, taken from different rose bushes? They have been sprayed with lime sulphur, malathion and lindane, and apparently to no avail. A.B. (Ashburton). Examination of the specimens sent in by you have revealed slight symptoms of rust, a possible spray damage which can have been caused by any of the

sprays used by you. A recommended all purpose spray for controlling most pests and diseases on roses, comprises- 1 ounce Captan <5O per cent wettable powder); i ounce Malathion (25 per cent w.p.), J ounce colloidal sulphur (75 per cent w.p.) to four gallons water. I would be grateful If you could identify the disease on the enclosed bulbs and advise of remedial measures to be taken, if any.—T.H. (Christchurch). Stem eelworms, the larvae of the narcissus bulb fly, are responsible for the browning and rotting of your bulbs. All affected plants should be lifted and incinerated immediately, and it is advisable not to replant bulbs in the same area for at least one year and a half. Thorough cultivation and removal of stray bulbs should be maintained during this time, and any future plantings of narcissus bulbs should be soaked in hot water for three hours at 110 degrees Fahrenheit, if their origin and quality are doubtful. Disease In Lettuces I have had several losses with lettuce plants both in the seedling and well develoned stages. The plants appear to be growing well and then suddenly collapse. Is this a virus or a soil deficiency? "Home Gardener" (Papanui). It would appear that your lettuce plants are being attacked by the fungus disease sclerstinia rot, but it Is difli-

cult to be certain without seeing the plants in situ. The only control for this particular disease is wider spacing of the plants in the ground. Complete removal, and preferably burning, of infected plants and disinfection of seed. Fungus on Cabbages Would yau please inform me what Is wrong with my cabbage seedlings? The ground gets plenty of well rotted compst, also a mixture of artificial manures Including potash, superphosphate, blood and bone, and sulphate of ammonia, and yet each year the seedlings go the same way. Is there something lacking in the ground, or do you think we are giving them too much artificial manure?— “Gardener” (Paroa). The seedlings revealed the presence of an unknown fungus disease. Until this has been identified no precise instruction regarding’ its control can be given other than to suggest ample spacing between plants and the rows, about two feet square is recommended. Spraying with bordeaux mixture at the rate of one ounce copper sulphate. It ounces hv. drated lime to one gallon of water during the seedling stage may also be helpful and rotation of crops should most certainly be followed. Concerning the use of artificial fertilisers there is no need to supply more than essential elements required. A 2-4-1 mix applied at the rate of five ounces to the square yard.