GARDENERS’ QUERIES

Press, Issue 32535, 19 February 1971, Page 5

GARDENERS’ QUERIES

Could you please give me a way to get rid of elm suckers. My neighbour has a weeping elm that sends up many suckers into my garden and has done so for years in spite of my cutting them back and digging back to the fence line. I have poured kerosene over the stumps but still they thrive and come up among my plants and some are now more than six feet tall.—‘Worried” Christchurch. It is not possible to stop a suckering tree such as the elm from continuing this habit. There is little or no suckering of elms where the wych elm is used as a stock. Suckers arising some distance from the parent can be sprayed with 2,4, 5, T. Could you please tell me the composition of a soilless potting mix indicating proportions and fertiliser additions. I take it that the U.C. formula might not be obtainable here so an approximation or substitute would serve. Most commercial mixes are very light in weight and contain possibly perlite or vermiculite.—A. B. Christchurch. The U.C. mixtures vary somewhat in composition but a sowing compost of 75 per cent peat and 25 per cent sand is satisfactory for a wide variety of plants. To every cubic yard of this mixture is added 6oz potassuim nitrate, 4oz potassuim sulphate, 2Jlb superphosphate, 4joz dolmite of lime, 1 jib hydrates lime.

Please find enclosed some minute lemons, a number of which have fallen from a 21-year-oid Meyer lemon tree. We had quite a good crop last year and there are some healthy ones on it this year. It has had the usual citrus food applied a few months ago and has since had Alaska applied. It has been kept watered. Can you give me the cause of the trouble.— E. W. Christchurch. Despite the fact that you state you have kept the tree watered, the symptoms suggest dryness as the cause of the trouble. It is quite insufficient, particularly under present circumstances, to wet the surface of the soil only. Moisture must penetrate and you should try to get it down 9in to 12in. Feeding tinder, dry conditions can also cause trouble. It was noticeable that leaf roller is or was present; and spraying with D.D.D. will get rid of this pest.

Could you please explain what is wrong with my pot plant. It was given to me at Christmas and now several leaves have withered. I did water it with egg shell water kept it in a cool place and now in a wanner place.— “Puzzled" Christchurch. Although the leaves arrived in a desiccated condition they did not show signs of disease but rather signs of poor cultural attention. Begonias require good light but not direct sunlight, and fresh air, warmth but not heat, and moisture but not

perpetual saturation. “Egg shell water” is not necessary. Enclosed please find a small bunch of Albany surprise grapes. The brown patch has appeared bn some (not all) bunches. This was first noticed three seasons ago in lesser numbers than this year. The diseased fruit is picked and destroyed as they appear. Over the period the vine has been sprayed with "Yates All Fruit Tree Spray” also a fungicide. The vine gets a bucket of water weekly when fruiting.— “Grapes” Christchurch. The most probable cause of this browning and softening of berries in bunches of grapes is sun scorch, which is usually brought about by excessively hard summer pruning thus suddenly exposing the fruit. At least two leaves should be retained beyond each bunch. Apart from this the only other thing that can be done to prevent such damage is to provide light shade. Spraying will not prevent scorch. Judging by the leaf specimen sent your vine otherwise seems very healthy. The “fruit tree spray” contains a fungicide so that there is no need to add another one.

Would you please tell me the cause of my peaches going rotten on the trees long before they are ripe. The trees are five years old, the variety is Million Dollar. Last year they were perfect and this year they have received the same treatment.—A.H. (Amberley). Almost without doubt, the cause of your problem is brown rot, probably the most serious disease which affects stone fruits. Apart from damaging the fruit at any stage from formation to post harvesting it can infect leaves, flowers and shoots. Frequent applications of dichlone during the blossoming period followed by regular spraying with captan until harvest should keep it at bay. All infected fruit should be removed from the tree and burnt. The disease can affect trees of any age. It is always present but may be more prevalent in some seasons than in others.

Can you tell me please whether there is some soil deficiency which is causing the yellowishness in the leaves of my lemon tree. The leaves are getting yellow around the edges with colour gradually extending and in the end the leaves drop. I have given citrus food to the tree every three months and plenty of water. A similar yellow streak is showing in marrow leaves but they are fruiting well. Is there something wrong with these too? “Beckenham” (Christchurch).

Many deficiency symptoms cannot be diagnosed to any degree of certainty without knowing from what part of the plant the leaves come from and by then making tests. Manganese could well be lacking but a magnesium deficiency cannot be ruled out on the citrus. You could apply Epsom salts as a foliage spray 3oz salts to 1 gallon of water. It is not advisable to apply fertiliser so often. Two applications one in late August and the other in December should be quite sufficient. Apply 11b for every year of the tree’s age to a maximum of 101 b, giving two thirds with the Initial treatment and the rest subsequently as suggested. The marrow could be suffering from spider mites, dryness or even a shortage of nitrogen.