GARDENERS’ QUERIES

Press, Volume CIX, Issue 32127, 24 October 1969, Page 6

GARDENERS’ QUERIES

I bought a yellow boronia in bud and almost immediately the buds fell, then the foliage. I sprayed with malathion with no results.—E.S. (Christchurch).

I As the trouble is not associated with insect damage malathion would not revive ■the plant. Boronias are very sensitive to root disturbance of any kind and must be handled with care, especially in the early stages when and i after planting out If the root ball is at all hard it should be softened before i planting by submerging in water for a few hodrs. Hand weeding only should be maintained around the plant j which, contrary to most Aus? tralian natives, prefers a moist but well drained soil. It is difficult to say whether your plant will survive but try cutting it hard back. Could you tell me what to do to combat a disease in the walnuts last year. The green cover developed a spot and stuck to the rat which in turn did not develop properly, was difficult to extract, and black inside. Probably after recent heavy frosts there won’t be any nuts anyway.—C.W. (Springston). Before commenting on this trouble I would like to see some samples of affected nuts which I suspect are troubled by walnut blight, the control for which is Bordeaux mixture. Some trees which I examined after the frost had blackened leaves but the inflorescence appeared to have escaped injury; but time will tell. Could you give some advice about two wisterias which have never bloomed properly. Each year before the leaves have fallen the sparrows pick off all the new buds and continue to do this right through the winter. Hie leaves eventually come through late in the spring. I sprayed it one year with Jeyes fluid but they were back on it the following day. It’s tantalising to see what should be a glorious sight ruined by these little wretches. "Anti Sparrow” (Nelson). Thiro spray has given some protection against birds. An

[alternative would be to purlchase netting—there is a very fine mesh type which covers a considerable area and folds up into a very small packet which would be ideal. Apart from this the only other suggestion is to devise a system of searing them off by intermittent, irregularly timed distractions. Jeyes fluid is not a repellent as such. Would you kindly advise regarding the enclosed polyanthus remains? The yellow powder is flowers of sulphur with which I tried to remedy the trouble though not knowing what it is.—A.W. (Christchurch). Trouble possibly stems from over watering or poor drainage and appears to be brown rot. The sulphur will not remedy infections as advanced as the symptoms displayed on your samples. If the other plants are similarly affected they are best dug out and destroyed. Could you please advise me how to rid my garden of eeiworm? I have applied D.D.T. super during the winter. How and in what position does one make a pebble garden? “New Gardener” (Cheviot). It is probable that you are confusing eelwonns with either wire-worms, millipedes or centipedes of which wireworms are the most destructive and centipedes relatively harmless. A pebble garden can be made anywhere in the garden although to be effective it must blend in with the surroundings and should preferably be kept away from, and free of, deciduous plants. There are several ways of putting down this form of garden. Pre-emergence weed killers can be used instead of using polythene or perhaps a thin skin ot cement grouting below the pebbles. For the last six years I have had a rosebush on which the leaves look slightly silvery. They are all strong growers and very healthy the year before. Each year I have dug the bush out but last year left Josephine Bruce (the second of tiiis variety to have leaves like the enclosed) and it died after coming into leaf this year although the leaves looked a good colour. Is it a disease or would a spray help?—Puzzled (Cheviot). The symptoms are those of silver leaf—a systemic fungus disease for which there is yet no cure. It is probable that there is an old diseased tree or stump from which the pathogen is emanting. Avoid planting in the same place again with susceptible plants, particularly those of the Rosaceae family. Diseased plants should not be left abound but promptly burnt after removal from the soil.

"Plum” (Westport).—Your plum has contracted silver leaf for which read the previous reply. It is sometimes possible to save large trees from this disease by cutting hard back very much below the last visible signs of infection. This is not always effective, particularly on small subjects.

Would you kindly tell me what to do with cyclamen in the off season and when to repot them. What kind of soil should be used then?—R.F. (Christchurch). Cyclamen which have finished flowering should be gradually given less water and then be put outside under a bush or plunged into the soil in a shady corner. Repotting can be done towards the end of summer. Good loamy soil is satisfactory as a rooting medium for them.

When is the best time to lift tulips after flowering? I find that If I leave them until the leaves have entirely died down besides taking up space, the bulbs are rather hard to locate.— L.P. (Marlborough). It is not fully appreciated by many growers that the foliage of bulbs performs a vital and valuable function

in the process of food assimilation which is stored in the bulb. By cutting off the leaves this source is lost and flower size in the following . year can be greatly reduced. The respective site of each bulb can be marked to facilitate lifting after the foliage has begun to yellow and die down. Could you tell me where I could get hot caps as I have tried in several shops without success? M.E. (Christchurch). It seems the lack of demand for hot caps has caused their laek of general availability. Some of the firms who deal predominantly with commercial growers will be able to help. There are other stockists about town. Enclosed are gome pieces off my peach trees. I have several which are all raised from stones. Last spring one died and this year most of the others are dying of the same thing. When the leaves are about an inch long they just brown off from the tip and wither up. I sprayed ail the trees in late July with a Bordeaux spray and three to four weeks later with cuprox.— R.I. (Hamner Springs). It could be one of two diseases. although without seeing the tree or more samples it is difficult to be sure. It seems however that very late pruning was carried out and this is a. policy that should not be followed for stone fruit. Prune in late autumn to early winter and seal large cuts promptly. Bordeaux mixture is a very good spray for stone fruit and should be applied prior to leaf fall, at bud movement and then ten days later again. Lime sulphur is a good alternative. Any diseased shoots should be cut hard back to a healthy bud or branch junction and a fungicide such as captan applied right away. Secateurs should be sterilised between cuts as stone fruit blast which this disease could well be can be transferred by them.