Gardener’s queries

Press, 20 December 1985, Page 12

Gardener’s queries

I have moved to a property which has a Mercury Bay lawn and find that white clover is taking over in patches. (1) What spray can be used to kill the clover without affecting the lawn? (2) Is there any special treatment required to keep the lawn green? L.C. (Motueka).

Weed control in dichondra lawns may be a little problematic at the moment as the most effective preparation for the purpose, Enide, is currently not being marketed in commercial size packs. However, small packets may still be available from various retail outlets and it would be advisable to make a few local enquiries. The other alternative is to apply diuron. Lawns of this type should be well watered during dry weather.

We have experienced problems with many of our vegetables as per enclosed, grown on a new section which was part of a former orchard. Also, could you advise why healthy beetroot goes to seed before maturity? We would really appreciate your help in these matters. N.K. (Chch).' Unfortunately, the samples arrived in such a dessicated condition that it was almost impossible to differentiate between the kinds of leaves, let alone make any kind of diagnosis. It is essential to send fully representative samples wrapped in polythene, and to avoid folding or providing fragments. Beetroot tends to bolt under too cool conditions particularly if it prevails for more than a week. There are a few varieties which are more resistant to this sort of thing, such as Cylindrica and Bolthardy.

I recently bought a home which had an old and neglected garden. This I cleaned up and planted. The problem is that all tender plants such as melons, cucumbers, pepinos and tomatoes curl up and wither. Seedlings don’t thrive after coming up, and a grape vine planted a week ago already has curled growing tips. I am urgently in need of advice as to what to do now. D.C. (Chch). From the information supplied it would appear that all the problems are related to chemical contamination. This

possibility can occur through drift from nearby application bf herbicides, pr residues of such in the soil or plant remains. Problems of contamination can also occur from compost which has had treated grass cUppings or weeds added to it,, or the use of straw from sprayed crops. Rectification of this type or problem depends on many factors'and could be especially difficult where such sensitive plants as those mentioned are involved. Apart from ascertaining what has been used in the area, changing the. soil and/or drenching of the ground with water are really the only alternatives to overcoming your predicament if chemical contamination is the cause.

Enclosed you will find a cutting from a fairly large camellia which is encrusted

with things that Jock like grubs, but are just powdery. The topmost branches are very badly infested, while two neighbouring camellias are perfectly clear. Could you identify, the. problem and advise cure? MSr (Timaru) The encrustations on the sample of camellia are scale insects. Infestations which are not brought under control will eventually cause debility in the plant Although there is a certain amount of varietal susceptibility to pests, and diseases, this should not be relied on and in the process of dealing with a stricken plant it is wise to attend to those which appear healthy at the same time. Apply all-seasons or summer spraying oil as an over-all coverage, but avoid very warm, sunny days when doing so.