GARDENERS’ QUERIES

Press, Volume CXII, Issue 33058, 27 October 1972, Page 6

GARDENERS’ QUERIES

Could you please advise why so many of my narcissi and daffodils have not flowered this season. They all look healthy although they have not been lifted for some time. The same goes with my Fritillaria imperialis — again healthy looking but no flowers. Is it the season, as I have heard of others not flowering this year?—“Elizabeth’ (North Canterbury). There has not been a noticeable lack of blooms this season from these bulbs that I am aware of, and it could be local. While this is again one of those problems where it is hard to pin point the cause there are several possibilities. Dryness could be contributory, particularly in the cause of the fritillaries which do best in a cool, moist fertile soil. The narcissi could be crowding each other out and therefore are unable to get sufficient nutrients to produce blooms. Fritillaries, on the other hand, can be left undisturbed for several years as a rule, providing that they are growing in suitable conditions.

I have a peach tree that had lovely big peaches late last year. However, we were not able to eat any of them because they went bad before they were ripe. Could you please tell me what was wrong and how to prevent the same from happening this year?— “Peaches.” (Christchurch).

The most likely cause of the fruit rotting is that they became infected by brown rot. This is one of the most prevalent diseases of stone fruit, particularly of peaches; it can attack and kill blossom as well as fruit at all stages and even after they have been picked. Young laterals can also be killed. Control starts with good hygiene by picking off and destroying all mummified fruits in winter and likewise doing the same with any fallen ones. Dead shoots should be well pruned back. Bordeaux mixture or lime sulhpur should be applied at bud movement without fail and during the year captan should be applied at blossom, fruit set and thereafter at two or three weekly intervals where infection has been severe. It even pays to apply a spray four days before picking and to make more frequent applications in periods of muggy and wet weather. The enclosed leaves from a pear tree are causing concern. This blemish has occurred on two branches and I have never seen this before. Could it be a form of bladder plum.—H.S. (Sumner). This blotching of the leaves is caused by an insect and is not a disease, or in any way related to bladder plum which is a fungus disease. The pest is commonly known as pear leaf blister mite and it seems to be a little more prevalent in home gardens this year. Initial control before flowering consists of spraying with lime sulphur. Thereafter D.D.T. or carbaryl

should be used. No insecticides of any sort should be applied during the flowering period and if using carbaryl care must be taken not to apply it within three weeks after petal fall as it has a thinning action on some fruit. I recently acquired a property with established swan plants on it. This pleased me as I am looking forward to raising Monarch butterflies in the summer. With the end of winter however, the plants generally seem to have gone downhill. There is browning of the end of the leaves followed by die-back of entire limbs. All leaves and stalks are dull, and there are very few healthy green leaves left. Can I save these plants.—B.G. (Rangiora). You probably have a specimen of Ascelpias physocarpa which has a tendency to look rather sick over the winter months under cold conditions, apart from which it usually has a life of but a few years. Fresh plants are easily raised from seed contained in the balloon-like pods which are freely produced each year by these plants. We have a large glasshouse that previous owners on our place used for tomatoes. As we do not wish to do this we are wondering if we could grow such things as tamarlllos, black passion fruit and possibly citrus fruits such as mandarins. Could you give us some idea whether this is worth trying. Also, how would we cope with soil sterilisation with permanent plants in the glasshouse.—J.H. (Christchurch). It is not necessary, nor is it possible, to sterilise glasshouse soil when there is permanent planting. With temporary crops such as tomatoes which are prone to disease this becomes essential if healthy plants and heavy cropping are to be maintained. Size of the glasshouse together with ancillary facilities would largely govern what can be grown and the feasibility of any such enterprise also depends very much on personal ability. Tamarillos and passion fruit, also grapes and cucumbers are possibilities. The best advice to you is to ask the Horticultural Division of the Department of Agricul-

Iture and Fisheries, which may be able to help more directly. What do you recommend for fertilisers for trees and shrubs, in particular. “Mixture” (Ch. Ch. To be quite frank the answer is “nothing,” but I would qualify this as follows. The average garden is capable of supporting most kinds and varieties of plants reasonably well. Some plants by their very nature of growth need more than others; many plants will do better with some feeding; others resent this. It ail depends on the circumstances as for instance when getting a newly established area under way. Again, it is not really possible to generalise and each place and plant should realty be taken into consideration on its own merits. A mixture of blood and bone and potash, 6:1 by weight respectively, is a well balanced mixture which would suit most plants. Would you like to tell me please, what is wrong with my Musa ensete (Abyssinian banana). It grows perfectly, plenty of leaves, new leaves coming all the time, but all at once the leaves get covered with sort of very fine “sawdust” and the bottom leaves start to get brown. The plant is in a very sunny position and gets plenty of water. I will be grateful if you could tell us what to do. I am using a proprietary house plant insect spray, it does not help much, and burns the leaves if I spray too close. The mealy deposits, or “fine sawdust,” as you aptly put it, is in reality a very thick population of mites, which would account for the sickly appearance of the plant over all. These pests can be very troublesome on these and many other indoor (as well as outdoor) plants. Control is best achieved by a specific miticide such as keithane rather than a multipurpose spray. Spray damage is always possible, various factors being influential in this direction. Certain chemicals, too concentrated a preparation or excessive spray in one area either through applying too much or from run off collecting in one place and strong sun at the time of spraying are some possible reasons why sprays can damage foliage.