Gardeners’ queries

Press, 19 April 1985, Page 9

Gardeners’ queries

This devasting weed is slowly taking over *y lawn- It appears to be prfdy. Could you identify it, ind advise suitable spray tha kills broad leaf as w»? “Interested”(Chch). The weed fl question is onehunga wee; which can become quite in«ive during the early part,of ummer. Bromofoenoxim • formulated specifically f< its control, and is best applil in the heat of the day whe the temperature is 20 degree C or above. From tb enclosed photo could you te me the name of the climbinplant growing on the mailbos We have very hard frosts lere, and would • like to have plant to climb up and arotd the bread box at the gate. .W.(Mawherati). It looks v<y much lite a variegated y of the snaT leafed varty. The ivies ar very hardy nd toleranQo i wide range i conditions, fics pumila, the reeping fig.covd probably survive / yor weather. Bh Parthencisus (Virginia ceper) and Lm-' ceras (honsuckles) quid be grown, butare probtfly too rampant fothe situajon. ind you could try Metosidros diffusa. / i (1) We ave two chetnut trees at lest 20 yeas olt The common/ horse ' chstnut

flowers prrffically and the nuts na turf to good size. The sweet chessut, which is close by, aso /owers prolifically, but tie sits are very small and ievC mature. We have giver it plenty of water and nitrgen but this does not seer tc have helped. Is there anywsy we could get it to prcuce mature edible nuts? (2)>Ve have a bad infestation ofxalis in our violets beneath shrubbery. Is there any way v can control this without imaging other plants? W.(Chch). (1) The two chestnuts are unrelated and while it is generally a foregone conclusion that the horse chestnut will yield satisfactorily from seed, this is not so with the sweet chestnut. Stock which has a proven inferior track record in the quality of its nuts will continue to do so. Quality and production of sweet chestnuts is perpetuated only by raising seedlings from nuts obtained from trees which have shown these characteristics, or by grafting from such stock. (2) Really effective control of oxalis is not possible unless all desirable non-woody plants are removed before applying a herbicide such as oxadiazon, or a sterilant such as dazomet and even then application using these preparations must be done with the greatest of care near any trees or shrubs.

Die-back of tomato plants. “Tomatoes" (Chch).

I regret that the samples were too desicated to enable any possibility of identifying symptoms. If the problem emanated from the soil following sterilisation then it is possible that this treatment was perhaps not as successfully carried out as it might have been.

The enclosed samples are from a tree which is about to flower. The lower limbs are encrusted with the fungus growth as in the sample, which is killing them. Pruning these would make the tree top heavy. Is there treatment we can apply to rid the tree of this growth? “Not-a-green-thumb. (Chch). The tree in question, Acacia baileyana, is suffering from a gall producing rust fungus. Apart from cutting off the affected branches, there is no control or remedial measure which can be applied to a badly diseased tree.

You recently had a question about white fly. I also have a small glasshouse and until now have been bothered with this pest. I have tried marigolds, etc., but this year I put an insecticide called “Parry’s Floral Air” into a plastic conttainer and hung it in the glasshouse. This product is mainly used in toilets and bathrooms. I used one in yellow paper, and left it like that when hanging in the glasshouse. It is very cheap and good. D.B.(Chch).

It should be noted that the product mentioned is not an insecticide but a deodorant. As such it is available in a variety of scents.

Gardeners’ queries should be sent directly to Mr M. Lusty, 56 Wayside Avenue, Christchurch 5. Samples should be separately wrapped in a plastic bag with air holes. Provide representative, good-sized samples, and your name and address. A nom-de-plume can be used for publication.