GARDENERS’ QUERIES

Press, Volume CXV, Issue 33774, 21 February 1975, Page 15

GARDENERS’ QUERIES

I hop* to grow a tangelo and a mandarine in tubs. Could you give me any advice on this, mainly what size tub (could I us* a half barrel), and also what soil and manure would be best? — L.C. (Darfield). A half barrel provides a very good receptacle for containing citrus trees. Such fruiting subjects respond to a friable rooting medium which contains ample well-rotted organic matter. A complete fertiliser such as the granular ones formulated for fruit trees with a good potassium content is ideal and should be "ell mixed into the soil before putting into the tub. Alternative--15, a mixture of blood and bone and potash in the ratio 10:1 can be made up. My 40-year-old Delicious apple tree has always borne a good crop. I have sprayed regularly winter and right through to autumn. The last few years I have noticed that the northern side of th* tree is taking on a lighter shade while those on the other side remain green. Sprays from last November consisted of combined captan, karathane and carbaryl at 4 weekly intervals. Is there any treatment you can suggest that I can undertake to cure this affliction? — "Delicious" (Christchurch). It is necessary to Include a miticide when spraying applies over the summer months as

these pests become more preva- ; lent over this period particularly, when hot dry conditions prevail. ’ The position which a plant oc- i cupies will often influence a! problem on one side only, such; (as you may get wind burn on the exposed side only of a tree. Al-r though karathane has slight con- ! trol over mites it is not suf- i ficient to control infestations for. ' which kelthane should be used. | I wish to remake one of my I asparagus beds. Would you please advise me the correct time to do this? Also I have a rose bush with twitch in it which I cannot get out. Could I dig the rose out and replant? — A.H. (Christchurch). 1 Roses are surprisingly tough i and tolerant of transplanting,! (and even a certain amount of! I mishandling. Where twitch or! other perennial weed growth has come up through the plant thereby making eradication almost impossible the rose bush should be carefully dug up : leaving as much root intact as possible. This should be [trimmed up with a pair of secateurs before replanting and I after the weed has been i completely removed from the (plant. All top growths should be ' shortened back to suitably placed buds; the bush should be resettled at a slightly lower level | than originally, particularly if it[ I is an old one; the job could be done in early autumn and after)

planting and firming well th» rose should be given a good watering. It is not clear just what is implied by your reference to “remake an asparagus bed.” However, the usual time for planting, etc. is in winter/early spring. Will you please identify the enclosed weed in our lawn? The children get very sore feet if they run over it barefooted and to pick it up I have been "stung" very often. I know of a lawn which had to have the top removed, dug up and resown through this pest. — W.A. (Christchurch). Due to the desiccated condition of the specimen on arrival, identification was not possible. However, it should be possible to eradicate it by means of an appropriate weed killer without having to go to the extent of turning over and resowing the complete area. Enclosed please find samples of three shrubs which worry me. (1) The tree lily of the valley — 5 years old, very healthy, covered with sprays in the same condition as the enclosed, t know the flowers should be creamy-white and sweetly scented. These are not and never get past the enclosed stage. Could you please tell me why? (2) 4 leaves from Pink Pearl Rhododendron. Two from the bottom — yellow, two from the top — a better green — what can I do? (3) Two leaves from Magnolia soulangeana, I think. Grows in the same area as the rhodo, which seems to point to some soil deficiency. — "Greensleeves" (Greymouth).

It is as well that you sent in a specimen of your lily of the valley tree so that it could be recognised for what it is, Clethra arborea. These trees are prone to mite damage and this can affect flowers. Both mites and scales were evident on the samples sent in. White oil may give you sufficient control for both these pests. The rhododendron has some scale on it also, and with the magnolia appears to have a slight nitrogen deficiency, a symptom which frequently shows up on the older leaves only. Blood and bone should be used to rectify the matter.

This autum I would like to plant a peach tree. It is a new section and all the top soil has been removed by the builders leaving hard clay. What should I do to prepare the soil for the tree? Also which type would you recommend for a small garden with this soil? — L.O. (Christchurch).

Although peaches will grow well on 'ighter soils than most top fruit generally grown, they react to an absence of nitrogen and water and also are intolerant df wet feet. If the soil has been denuded to the extent which you state, remedial measures should be taken at once before commencing any form of planting because it is doubtful if you will get any satisfactory results from whatever you try to grow. Top soil is essential to support life and this should be brought in to cover those areas where planting or sowing of any kind is envisaged. There are a number of dwarf peaches such as Bonanza which attain an ultimate height of about 2m but choice of vanities in this category is limited. From the regular | sized trees there is a range from very early to late maturing vanities, preference for which is really a personal matter.