Gardeners’ Queries

Press, Volume CV, Issue 30982, 11 February 1966, Page 6

Gardeners’ Queries

Reference to my previous request for plant identification, I herewith enclose further samples.—B. W. (Lons Bay). The blooms are those of Calochortus Weedii, a Californian native. It is sometimes referred to as C. Luteus Weedii.

I am enclosing specimens of leaves from my garden, which is a new one. A number of plants have done well, others have this mottling of the leaves as enclosed. I have given the soil a good mixed fertiliser and still this persists. The possibility of a previously applied fertiliser cannot be ruled out. Also the dividing wooden fence has, I think, been treated with a creosote mixture several years ago. The bed runs along the fence.—E. W. (Christchurch). Due to insufficient ventilation of the plastic bag, the leaf specimens arrived in an almost cooked state and it was only possible to make guesses at what the plant was and the symptoms. They looked like chrysanthemums suffering from virus, an inherited disease for which the only successful treatment that I know of is heat treatment. As this has to be applied for a considerable period at over 90 degrees F. it would not be worth your while or probably within your capabilities to administer same. Fresh stock is advised. None of the factors mentioned by you would be responsible, or effective as controls. I have a Meyer lemon growing in a tub and it is doing well. It has been in for two years but unfortunately I notice that some of the slats of the tub are showing signs of rotting. Will the lemon transplant and if so at what time of the year? If it will transplant, will age make any difference or, in other words, could I leave it for another year or two until the tub really does rot? — “Citrus” (Timaru). I do not think that you have much of a problem. If you wish to eventually transplant the lemon tree into open ground it is best to do so now as the young plant will recover very much more quickly than an older specimen. Wait until winter, dig a sufficiently large hole to take the complete root base but make sure that it is not too deep as collar rot can otherwise develop. The top-most roots should be at just below surface level. Thoroughly water plant before and after planting. I am enclosing some raspberry leaves. The canes have fallen off In production for the last two or three years, and an increasing number of the plants are showing this leaf discoloration. Is it disease, or soil deficiency? Should a fresh start be made with new canes? —“Aututnn” (Christchurch). Although the leaves convey the general impression of satisfactory growth, a deficiency symptom appears to be present while evidence of rust and the onset of mite infestation was also visible. Rust can be readily controlled by using a fungicide such as captan, zineb, lime sulphur plus colloidal sulphur. Summer oil (white oil) or even the use of lime sulphur will dispose of the mites. As deficiency symptoms are often quite similar it is important to know the locality of the plant from where the leaf specimens are taken and also some details of fertiliser treatments given, if any. It would be appreciated if you could forward this information together with further samples.

Could you tell me how to cure my onions as I am new to this procedure.— “Newcomer” (Christchurch). I refer you to last week’s gardening page, which appeared on Saturday instead of Friday. Brief details were given of the procedure. I have had good crops of apricots and peaches but each year much of the fruit has been spoiled by the entry of a caterpillar at the stalk end. When the fruit was small I sprayed with arsenate of lead but refrained from further spraying since then. Is there any effective yet harmless remedy you can suggest?— S. C. (Christchurch). The use of carbryl (sevin) is suggested. This will control all chewing insects and can be used to within one day prior to harvesting. A few weeks ago I noticed one of my tomato plants drooping and quite limp for the top bin. They were then 4ft high and looking quite healthy with the exception of one or two lower leaves, which had brown patches and were removed. Flowering was normal and at the time three fruit trusses had set. Regular watering and blood and bone etc. were given when young and three applications of cuprox had been given. Subsequently another plant drooped and others are now following suit. After a good soaking, which seemed to revive them temporarily potassium permanganate was applied but the trouble is still spreading. What is the trouble and what am I to do now?—G. G. (Christchurch). Late blight, a fungus disease which has a variable prevalency but can be very serious under suitable weather conditions, is responsible for the condition affecting your plants. Spread may have been increased inadvertently by yourself during watering. Potassium permanganate is not a remedial measure and. although cuprox is an effective means of control, it is probable that the interval between sprays was too long, insufficient in its coverage or badly timed. Once late blight has become established or conditions favour continued development. eradication becomes impossible. As a rule regular applications of Bordeaux mixture or alternative copper sprays, such as cuprox, maneb or zineb. will give control although Bordeaux mixture, which is still one of the most useful and reliable fungicides, can cause side effects, such as leaf burn, and reduced yields. As the disease can be carried over from season to season on decaying plants these should be burnt as soon as cropping has ceased. Our entire crop of marrows to date have turned soft and spongy when only a few inches long. The plants appear healthy with vigorous growth. Is there a spray that can be used to cure or control this, or perhaps you can suggest an alternative cure. The marrows are the green bush variety. —“Chester” (Christchurch). Insufficient pollination would appear to be the answer, a problem sometimes associable with prevailing weather conditions which may restrict the movement of bees and other insect pollinators. Damping down or hand pollination could overcome this trouble but continual recurrence of the matter is not likely.