Gardeners' Queries Answered

Press, Volume CII, Issue 30051, 8 February 1963, Page 7

Gardeners' Queries Answered

1 have a plant of Puya alpestris which was planted in 1955, and although it has made growth, ft has never flowered. It has leaves like a pineapple which are broad and serrated. According to description it should have stems tour to five feet in height on which flowers appear. Is it worth persevering with or would you advise me to discard it?—O.W.E. (Cobden). Puya alpestris may take many years before a flowering stem appears. After flowering the plant will die unless new rosettes of leaves are produced outside the old one. The flower stem, as you say may reach five feet and it will carry very many attractive flowers that are blue with a bunch of orange stamens. This attractive plant is not very common and is well worth persevering with even though it does take a long time to flower.

1 have a plot to which standard roses are growing and which has In recent years bad the overflow from a shed spouting pouring on to it. This has now been diverted and I have tried to enrich the soil with fertiliser and bine lupin without success. Could you suggest further treatment?— s Harewood.”

I am not quite sure what exactly it is you want to know. It is assumed that the plot which received the overflow was naturally dry and that your attempts to grow lupin on it was with the intention of digging this tn later to provide organic matter: the organic matter being to increase water retention If this is so. I would advise you to mulch the bed with compost or well-rotted manure now, and to work this Into the ground during the winter. It the soil is poor and you wish to feed it, you could apply blood and bone, dried blood or bonemeal. Could you advise me as to the trouble with my grape vines; specimens of leaves are enclosed. They are only about a third of the stee of the previous year, and are pale, sometimes mottled, instead of being deep green. The normal excellent crop was obtained last year but this year the grapes are small and sparse. The centre of the vine appears more sickly than the extremities. Lime sulphur and red oil were applied last winter. Liquid fowl manure has been applied in moderation and moisture has not been lacking.—B.O. A. (Christchurch).

I am not quite sure what is causing the trouble on your grapes. There are several possible explanations. There are traces of downy mildew present. While lime sulphur will control powdery mildew, it will not control downy mildew: Bordeaux is necessary for control of this disease. There is a suggestion of a mineral deficiency and I would also suspect a lack of pruning which is a yearly essential for successful culture. 1 have three black currant bushes growing on my section which is almost pure sand. Although I have put borrowloads of compost under them the fruit falls to get more than a third of the normal size and then it drops off. Apples and pears, however, seem to do quite well on this soil. Can you suggest a remedy in regard to the currants or do yon think that they are not worth persevering with? —A3. (Wainoni). Black currants do best in heavier soils which retain more water. I think that the trouble with yours is lack of moisture. The roots of currants are close to the surface in contrast to your fruit trees, where they go down much deeper. It always pays to build up a sandy soil with turning to a green crop such as lupins and applying a good heavy mulch after heavy ram or after a good watering and making sure that the bushes never lack at any time for water. 1 have three five or slxyear - old apricot trees which were grown from stones. They are about six feet apart on the south side of the house where they receive quite a lot of sun. Although they flower, they never seem to have any fruit; eould you tell me why? H.M.V.c. (Christchurch).

It la often a number of years before a seedling wffl produce fruit even though ft may flower, so it fa necessary to be patient. In your case pollination, to view of the position of yottr trees, could be an important influence on fruiting. Incidentally. all apricots are selffertile. which means that they can set fruit with their own pollen I suggest that you allow at least 15 feet between your trees to give them plenty of room for later development. I have aa eight-year-old Gravenstein apple tree which has hardly borne any fruit. That which is produced drops off before ft is ripe, ft has made a lot of growth even though it has

not been pruned for three years. The tree has been watered tftls summer and a mulch of grass clippings has been applied around the base. It would be appreciated if you could advise me i on this problem.—F.H.C., (Christchurch). Apples are divided Into two groups which are determined by the chromosome content of their pollen. The largest group is called diploids and produces good pollen whilst the other group, called triploid, produces bad pollen. The latter group should never be relied on as pollinators, either tor their kind, or for diploid varieties Each triploid variety should have two diploids planted with it to pollinate it and tor one diploid to pollinate the other Gravensteln is a triploid and as it is an early flowering variety it would require two pollinators that would flower at a similar time Granny Smith and Irish Peach would be suitable varieties.

Could you tell me what is wrong with my scarlet runner beans, sample enclosed? The shoots are producing neither beans nor flowers. Farmyard manure was dug into the ground last winter and mixed fertilisers were applied to the ground before planting. The seed was given to me by a friend.— NAJB. (Ashburton).

You say that no flowers were produced, yet on the specimens that* you sent there were flower buds. I assume, then, that these buds have been dropping off before they have opened. It seems likely that there is an excess of nitrogen in the soil, either from the manure or the fertilisers that have been applied. The condition wil) probably right itself but a drawing of sulphate of potash at one ounce to a yard of row would help to counteract the excess ot nitrogen.

A letter has .been received BJLK (Christohurcii) concentaf Datura wificto appeared in ‘"rae Press'* on January 25, 180. This letter ¥‘ d J be^ Bn ® S? •®re«i was A. B. Fraser. 52A Dyers Pass road, Cashmere. Note To Correspondents

Our apologies are extended to all those gardeners whose problems we have taken so long in answering. Due to limited space on this page and the number of queries received recently we have been unable

to answer one as quickly as we would wish. We ask you therefore to bear with us a little longer—patience has its rewards!