GARDENERS’ QUERIES

Press, Volume CXIII, Issue 33264, 29 June 1973, Page 11

GARDENERS’ QUERIES

I am planning to plant a 1 lemon tree this winter. 1 Would you please advise I me on the soil preparation? < Our subsoil is sand but I over the years I have < improved the top soil con- i siderably by the constant ’ use of compost. — J.A. < (Christchurch). Citrus are responsive to 1 good soil which is moisture ' retentive but not subject to ) water logging; they are not ■ deep rooting. Your prepara- ! tions may be adequate. One 1 point, however: digging over 1 and composting should not be confined to the immediate vicinity of the planting hole, but extended round it. This applies to other forms of planting also, particularly in the case of new ground which is being broken in for the first time. Unless the position ( is well sheltered it is advis- , able to delay the planting of , the lemon until early spring. ( at which time one pound of, blood and bone should be , incorporated with soil in ) which the tree is planted. Could you identify the ; enclosed plants for me 1 please? — P.K. (Christ- ; church). i (1) Billardiera longiflora.ji (2) Aquebia quinata. (3)p Coprosona. Enclosed are a number of black currant cuttings ! which have holes in the wood and in many cases blackened hollow centres. 1 Some of these cuttings had actually broken off at various junctures and it I seems to me that all is not ! as it should be. Could you | comment please? — “Ribena” (Christchurch). The boring in and tunnel-j, ling of black currant canes is; caused by caterpillars of the; currant clear wing moth. These pests can be quite destructive and control of them is difficult, although the application of D.D.T. or carbaryl in spring, together with 'the burning of all i infected prunings, may help. ; Scientific investigations of this insect are in progress I now. I have a problem with a recently sown lawn. This is I relatively flat but partially shaded during the day. It came away fairly well in association with copious watering. Now it has tended to develop a mossy covering with what appears to be a greenish slime over it. What would be the i reason for this tendency, and is there anything that can be done about it? — | The fact that algae slime has developed suggests that ; there is some surface water; present, as it will not develop ; in a well drained area. The area could be slightly dished ■ to cause an accumulation. The shade could cause excess i moisture to remain rather ' than become absorbed. It is ) also possible that the soil was tramped or sealed or ; could be of a very tight ' | nature, despite the fact it : may have been initially’ well worked. This compaction is : not unusual where soil has : been worked to an excep- ’ tionally fine tilth, has clay in I it, is compacted before seed 1 sowing and then heavily 1 i

watered. Probably the best treatment at this stage would be to fork the area. Reverse a fork so that the handle lies towards the body, drive it in 4 or sin vertically, give a slight forward and lateral wrench and withdraw vertically. Repeat this at 6in intervals. For slime you could spray with Condy’s crystals at the rate of one ounce per gallon of water applied to 10 square yards, but this is only a palliative if drainage from the surface is poor. Is there a treatment to get rid of bamboo? I have a large clump which always comes back, despite hard cutting back — it is a real curse. — “Fed up” (Kaikoura). Bamboo is difficult to control with weedkiller and although there are several which could be used, persistent treatment is generally necessary. You could try sodium chlorate at the rate of lib to each square yard. This should be scattered over and around the plant after it has been cut down; water in and use a wetting agent in the water to assist in adhesion of the material on ■the plant’s roots. Be sure to ! remove all plants from the Immediate vicinity of the i bamboo before applying the ’weedkiller. Nothing will grow! lin the area for perhaps two! or three years. Do privets require pollinators to make them berry? I Ours flower but do not ! produce any berries to speak of. — J.H. (Ashburton). Privets do not require ! cross pollination, as they are ! capable of setting fruit on ! their own. It sometimes takes several years, however, before they bear berries. Apart from this there is nothing that I can suggest to make them berry.

I have a beautiful spreading Spanish chestnut tree. Every year it bears countless nuts which fall to the ground, bounce out of their pricly cases and are eaten by birds or farm animals. Only once have I found a young plant growing among the decaying leaves, and it did not survive transplanting. This year I have gathered several ,Ju.np undamaged nuts, which I hope to propagate. Could you tell me the correct procedure and following treatment. —E. G. (Ashburton).

I am not sure whether birds favour sweet chestnuts, but ornithologists might be able to help in this direction. The nuts are eaten by some animals, but it is surprising to note that seedlings have not more frequently developed, since you mention that the nuts are well developed. Transplanting of any seedlings must always be done with the greatest of care, as in lifting them the tap root is enevitably broken. There should be no difficulty in raising plants from seed, which could if desired be budded or grafted in the following year. Seed should be sown now but could be strat-

ified in moist sand first before planting at least one inch below soil level. No special treatment is required but it should be noted that the s.zeet or Spanish chestnut apparently resents lime. We planted out some passion fruit seeds and set them out in pots to get strong, but unfortunately although they were doing very well some of the leaves are going brown and seem to be dying. I enclose one of the leaves; one plant is quite dead and others may follow. —F. D. (Kaikoura).

Although the feeling is that the seedlings are dying from damping off disease the sample is too small and singular to determine this. It is important to ensure good drainage for seedlings, more so for some than for others. The potting compost should be friable but moisture retentive and it is sound policy to apply a fungicide such as captan, thirm or benlate to the plants and soil, even going to the extent of using it when sowing the seed.