Gardeners’ queries

Press, 12 April 1979, Page 14

Gardeners’ queries

I am enclosing a leaf from my rubber tree and would be grateful if you could advise why the leaf turned the colour it nas. Two or three of the leaves have this same colour and have fallen.—" Puzzled" (Hokitika). !> coping, discoloured and falling leaves are probably the most common changes in rubber plants in the home. Anv or all of these symptoms are usually indicative of overwatering but occasionally similar such symptoms can be caused by insufficient moisture. Over-watering induces more of a Umpness of the affected leaves, whereas the leaves of plants which are suffering from dryness tend to reflect

this in themselves. Rubber plants do not need wet conditions and will do well if the soil is kept consistently “just moist. ’’ I bought an almond tree as simply "a flowering almond." As a result of last year's beautiful blossoms it has set fruit which are about the size of a walnut. Can you please give me some advice on whether these nuts are edible and if so how do I go about picking and drying them? Also, how do I prune the tree, if this is necessary? — "Happy Gardener" (Ashburton). Flowering almonds will produce fruit but the fruit may or may not be fertile and the kernel, which may be of variable size if it forms, can

be bitter or sweet. As the fruit ripens and matures, the fleshy portion dries and then splits open revealing the nut inside. They can be picked from the tree at this stage or allowed to fall and be regularly collected from the ground. The shells should be split open to extract the kernels which should be well dried before storing. Flowering fruiting is on one-year-old wood and spurs produced on older wood. After initial shaping over the first two to three years pruning should be kept to a minimum with removal of dead, diseased or misplaced growth. I am at a loss to know what to do about slugs in my garden, which appear to have overrun it. The lettuces are full of them when fully grown; potatoes are honeycombed with holes; the leaves of tomatoes, dahlias and polyanthus have likewise been eaten. The pellet form of slug bait is used but is not effective to prevent this damage nor is it practical over a very large area. Could you suggest any solution to my problem?— J.T. (Chch). Slugs are particularly troublesome in wet w’eather and can do a considerable amount of damage to the plants on which they feed as well as fouling them with their droppings. Plants injured by feeding slugs also become vulnerable to disease. A major step towards reducing slug activity is to remove all refuse, weeds and any other material in the garden which can provide handy refuge for them. Baits containing metaldehyde are still considered to be the most effective in dealing with them. A simple home-made bait consists of a thorough mixture of metaldehyde and bran in the ratio of 1:24, by weight. Another remedy consists of a mixture of one part of alum to seven of slaked lime. One other point to note: looper caterpillars have been extremely active this autumn and have ravaged the leaves of all sorts of plants, so it is quite possible that some of the damage attributed to slugs has in fact been caused by these caterpillars.

We have a very fine crop of grapes ripening but find that they are being spoiled by blow files and wasps. We have not had this problem in previous years and would like advice.— W.H. (Chch). Either disease or birds, or both, are Initially responsible for attracting wasps and flies to grapes; heavy rain can likewise split open the fruit and thus attract insects. The use of netting is definitely advantageous in keeping birds from getting at the ripening grapes and various baits such as sugared water placed in jars suspended from the vines will act as traps for wasps and blow flies; the jars should be capped but with a hole in the cover. Could you please identify the enclosed weed for me. It comes from our lawn.— "Interested" (Chch). The weed is a native oxalls known as Oxalis corniculata; it is becoming fairly common in many lawns. Could you please advise me on varieties of nut-producing trees suitable for the Canterbury climate and also any special considerations concerning their establishment, growth and ultimate production.— "Nut-nut" (Amberley). Suitable nut-bearing trees for the Canterbury area include chestnuts, hazels, walnuts, almonds, and, just possibly in your area, pistachio. Nut-growing and research on all aspects pertaining to them is only in its infancy here and every one is learning ail the time. Shelter and late spring frosts are two of the most important considerations for anyone interested in growing almost any kind of nut trees. The Tree Crops Association is vitally concerned with producing crops and now has 14 branches throughout New Zealand with a membership in excess of 2000. Membership, through subscription, entitles one to receive a periodic journal, attend field days and generally be kept informed of "nutty” matters. Subscription is currently $6, payable to the treasurer, Mr G. Allen. P.O. Box 22-463, Christchurch.