Gardeners’ queries

Press, 19 December 1986, Page 18

Gardeners’ queries

GARDENING

by

Mike Lusty

Our lawn is full of Onehunga weed. It has been consistently sprayed with Faneron 50. While this is usually effective for the season it has not eradicated it completely, and it is now covering a large area. Could you recommend treatment? C.G. (Chch). Faneron is regarded as a specific treatment against Onehunga weed, to be applied under warm conditions before the plant seeds. Alternative herbicides which are effective include the combination of 2,4-D and dicamba, and MCPB. Following weed control, bare patches should be resown with grass seed, or turfed, and fertiliser applied to the whole area to encourage good growth of the lawn.

Can you identify the problem with this evergreen azalea? Apart from the peculiar growths on some of the leaves, the plant seems otherwise healthy. M.A. (Chch). The gall-like swellings on the azalea leaves have been caused by a fungus known as azalea gall. This disease becomes obvious at this time of the year and is likely to recur on those azaleas which have become infected by it. The galls can be removed by hand, and control can be achieved by spraying with a copper-based material, or zineb in the early spring. Enclosed leaves are from a fully grown fir

seems to be slowly deteriorating. Neighbouring trees seem very healthy. The hollyhock leaves are representative of most of the bottom leaves from most of the plants here. The leaves from the lemon are now similar to the enclosed and fruit is blemished in the same way. Is it a mineral deficiency? “Snowy” (Lake Tekapo).

The lemon tree is infested with mites plus a few crawlers (young scale insects) noticeable too. Suggested treatment is the application of summer/white, or all seasons spraying oil. Thorough spraying is necessary to ensure that all parts of the tree are treated. It may be advisable to repeat the application within three weeks; avoid spraying under very warm, sunny conditions. Dusting with sulphur, or the application of zineb, is recommended for the control of rust on hollyhocks. Badly infected leaves should be removed and burned. It is doubtful whether much can be done to treat the fir for needle cast because of its size, otherwise one of the copper-based fungicides could be applied.

There are some small insects on some of the hazel leaves enclosed. Could you identify them and suggest a control? A.G. (Chch). The insects noted on the leaves are lady bird larvae, many of which are extremely useful predators of undesirable insects.

My tomatos have problems, as you can see in the samples. Can you help? “Keen Gardener” (Hokitika). I regret that it has not been possible to assess the problem positively as the complexity of many problems associated with tomato plants requires very adequate samples for a diagnosis to be made. Unfortunately, a transit delay due to the need to readdress the mail partly contributed to the dessicated condition of the specimens on arrival. Some of the main points to observe with tomato growing are ventilation/aeration, the avoidance of moisture stress as much as over-watering, prevention of mite and aphid build-up, good drainage, and adequate nutrient availability. Gardeners’ Queries should be sent directly to Mr Mike 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 Soused for publication.

Embothriums belong to a select group of plants which have gained particular popularity in certain parts of Christchurch, but are far less noticeable elsewhere. Closer investigations may reveal some significance in this observation. The fire bushes are certainly very promiment when in full flower from mid-to-late spring. This member of the Proteaceae family comprises a very small genus of evergreen trees, mainly from South America with one species from Queensland. Embothrium coccineum, the Chilean fire bush, and its form

folium* above, is one of the hardiest as well as best known and probably most generally grown here. Its fiery crimsonorange flowers are somewhat reminscent of the honeysuckle, but it takes several years before these trees begin to flower profusely. Once open, the inflorescences retain full splendour for two to three weeks, much depending on the prevailing weather.

This is not a tree which will like any sort of pampering — good drainage but a moistureretentive medium, with an adequate annual rainfall and little attention will usually suffice.