Gardeners’ queries

Press, 31 March 1989, Page 7

Gardeners’ queries

1 recently removed a tree from the centre of a lawn which you put down for me several years ago. The problem is that the grass seed used to resow the area has produced a hard and different grass from the fine grass you used. Even the electric mower will not cut it. How can I kill it, how soon after treatment can the areas be resown, and what kind of seed mix should I use? P.B. (Chch). There are various grass mixtures available for different purposes. It is also possible to purchase individual grasses to make up a desired blend. The preferred mixture for fine grass lawns has been of chewings fescue and brown top, 2:1, respectively, and generally applied at the rate of 30g per square metre. Greater reliance on fescue is now considered desirable and a mix of up to 4:1 could well be used. Paraquat will give a very quick result with the least residual problems enabling resowing shortly after desiccation of prevailing grasses.

Can you advise how to control flies on the compost heap? Fallen fruit, kitchen scraps, and weeds are all put into the heap which is turned every three months. I am loath to use organo chlorines because of their persistence in the soil. Could you also comment on the striping which has become evident on the nectarine tree recently? J. H. (Chch). The best procedure for reducing fly presence around a compost heap is to avoid just throwing scraps on it without covering them. If applied in layers which are topped with soil, saw dust, or some other compostable material the fly problem

can be minimised. The mottling of the nectarine leaves is strongly suggestive of manganese deficiency. Manganese sulphate sprayed on the young leaves in the spring time is effective, at 6g per litre.

Can you please identify the plant enclosed and tell me something about it? It is very invasive in the garden, growing over everything and twining itself around things. It seems to sucker a lot and the roots are very long and hard to eradicate. It has small, thorn-like things along it. C. F. (Horrelville). The plant material sent

in for identification looks very much like elm suckers, although this does not tie too well with the description of its growth tendency. Spot treatment with amitrole is suggested as control and this will probably have to be repeated on any regrowth.

Until about one month ago my three-year-old lemon tree looked quite healthy. It has been well fed and watered, and sprayed with Shield. Could you advise me what is causing the brown spots on it? P. K. (Chch).

No conclusive evidence of the cause of the problem could be determined from the leaf samples as there are several diseases and a physiological disorder which can display similar symptoms. Has the fruit been affected; is there die-back of the twigs; what is the condition of the bark, especially close to ground level?

Could you please advise me how to eradicate oxalis and hydrocotyl from an established

lawn on a dry Port Hills site? The oxalis is the small leafed type — it withers when sprayed with banvine but later resprouts from the bulbs. “H” (Chch).

Both these weeds continue to present something of a problem, for most home gardeners to control as inost, if not all, the available proprietary herbicides in small containers do not give adequate results. Currently, the following combinations give good control: picloram plus 2,4-D, and diclorprop, brom-oxynil plus M.C.P.A. A follow-up may be . necessary. Autumn applications generally give the best control.

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 be used for publication.