Gardeners’ queries

Press, 18 February 1983, Page 14

Gardeners’ queries

GARDENING

by

M. Lusty

My apricot tree which bears well has fruit with scars and grooves no matter what the season, whether watered or not. Would this be because it is grown from a stone and not grafted? The parent produces excellent fruit. J. and J. M. (Chch). This apricot tree is suffering from peach scab, a not uncommon ailment of these fruit as well as peaches and other stone fruit. Where no controls are implemented this fungus disease can become persistent and severely affect the quality of the fruit, this disease can. also attack the foliage, and shoots on which it may persist. There is some varietal susceptibility. Seasonal spraying with triforine is recommended. Brodeaux mixture should be applied prior to leaf fall and again at bud movement when spraying oil should also be added. Incidentally, young fruit trees are usually raised by buding not grafting.

I would be grateful if you could identify the four shrubs, and tell me what their approxi-

mate heights, diameters and moisture needs are. Also, could you tell me what is wrong with the rhododendron — some of the new leaves have come like this; what can be done about it? P.C. (Chch). . The four shrubs are named as follows (1) Euonymus fortunei "Silver Queen,” (2) Euonymus fortunei "Emerald Gold," (3) Hebe hulkeana (form), (4) Hebe Ohrusta (form). The brown covering on the rhododendron leaves is tomentum, a soft matting of hairs which is often more pronounced on young leaves than on the older ones and is common in many plants apart from some rhododenrdons; it is nothing to be concerned about. The names of the Euonymuso is that by which they are most commonly known as. These particular plants make fairly compact ground covers which may attain a height of 45l)mm. Could you please tell me why our potato crop has clusters of the enclosed growing on all the plants? We have grown potatoes for 25 years in Southland and have never seen these before — we grow mostly Kenebecks. Ours is a new section, probably never having seen a spade before. The tops appear healthy. The insides of these “seeds” show the plants apparent relationship to the tomato. T.B. (Chch). As you have surmised, the potato belongs to the same family as the tomato. Until re-

cently the general method of growing the former was by vegetative means from the tuber, commonly called the seed. Recently true seed has been made available to both commercial growers and home gardeners, and is obtained in small packets just like any of the vegetable seeds which have been in use for so long. The seed of potatoes is contained within the green berry mentioned .by you. Not all potatoes produce these berries in any quantity, much depending on the variety and season. However, although potatoes tend to self pollination, unless isolation and hand pollination is resorted to, the progeny is likely to display variation from the parent. Kennebeck is a comparatively shy bearer particularly when compared with Rua; Ham Hardy, similarly does not fruit much. Enclosed cuttings from a Nellie Moser clematis. The plant was making excellent progress and due to flower, when one section started to dry off and quickly collapsed. We have had a lot of rain and some cold winds but the plant is growing in a position of excellent drainage. I hope that you can identify the problem. E.P. (Chch). It is highly possible that this stem rot is associated with a root disorder. In spite of your assertions as to good drainage the problem is still considered to emanate from the ground. The soil level round the plant could

be raised and the clematis planted on this higher level. Also recommended is spraying with a copper based material which should be applied to the whole plant and the root area; repeat at least once in two to three ‘weeks time. 1 have recently planted a grape fruit and a Meyer lemon in t sheltered spot but they will individually, require frost protection in the winter. Could you please advice the best way to achieve this? C.B. (Ellesmere). Probably the most important aspect in providing frost protection for citrus is to avoid planting in a position which gets the early morning sun, lies in a frost pocket, or is likely to be in the path of cold winds. Apart from this, structures which can support a scrim, fine mesh netting, or even polythene cover, clear ol the developing citrus will pro-; vide good protection. However, unless the plants are in a reasonably sheltered position it will be difficult to avoid really cold weather from affecting the early fruit which tends to be on the dry side under such circumstances. Gardeners’ Queries should not be addressed to "The Press." but be sent directly to Mr M. Lusty. 6 Brockworth Place, Christchurch 1. Samples should be well wrapped. Queries can only be answered in this column.