GARDENING NOTES

Evening Post, Volume XCVII, Issue 103, 3 May 1919, Page 12

GARDENING NOTES

(By "Experience.")

HEDGES.

What is best to plant to form a. hodgo? Thi6 is a question frequently asked. There is a. quite wide range of suitable plants, And nearly all are capable of forming a good hedge except. the Chatham Island ake ako (Olearia Traversi). This is so much injured by borers that jt invariably becomes more or less ruined soon after reaching a useful size. A number of species are subject to certain pests, mostly insects. Laurestinus is subject to thrips, euonymus and holly are attacked by £oale insects (a different sca-le on each species), golden ake ake (Olearia Forsteri) is attacked by gall insects. Pittosporutas of most kinds are subjeot to scale insects, and all are more or less liable to lose branches by tho borer or by girdiers. Except in the case of the Chatham Island ako aks these attacks are not eerious. The species least liable to insect attaoks, so far as my observations have taught me, are pittospoxum crassifolium and eloagnus joponica, and oven the last-mentioned plant is attacked by a, scale insect (Aspidiosue Rossii), but only in extra, hot places. That insect attacks' are mainly duo to unsuitable conditions, or, at least, that serious attacks are traceable to this cause, is proved by tho behaviour of the planrs in different localities. Tho holly is scon in greatest perfection on. the south end of the Middle Island (Dunedin and thereabout). It will scarcely; grow at all in Hawlscs Bay, but does fairly well about Wellington. Other examples might bo quoted were it worth while, e.g., one might mention cases where in the same locality good hedges and bad ones of the same species can be seen, but though the locality is the same, tho conditions are differont, It ia evident that success depends on the plants getting what they want—being given, in fact, a reasonable ohance. Where failures ocour it is always because the hedge is in some way starved. The golden ake ake is never much troubled by the gall insects when, planted in, good soil with a reasonable amount of moisture. Plant it on the edge of a. bank, where the soil ie bone dry most of the year, and the galls take possession. After all, it is lack of growth, and not the gall, that is the oaußO of failure. In. such a. position euonymus, which has a more spreading root system, would do better than ake ake. Laurestinus is damaged by thrips only where tho soil is bone dry for a. long pqriod. This may be caused by the proximity of a. dense plantation of trees, I ex by other conditions that, deprive the roots of moisture. The eleagnus would ■do better near a plantation, for its roots are rambling, aud would find sufficient moisture whore the la-urestinus might starve, and further, the leaves of the oleagnus are better equipped to stand drought. PREPARATION OF GROUND. Insufficient preparation of the soil ia > frequently the cause of failure. If it is * possible to tronch the whole of the surrounding ground all the better; Where the area, is small, and its configuration permits, it should bo done. Paths and lawns should be laid o2 after trenching. There are places where the soil is of a nature that does not iiced trenching—in the Hutt Valley, for instance, and rich flats in the Man&watu. Every place in suburban Wellington requires trenching at least two spits deep. "If it is not possible to trench the whole area—it is not always possible on the hills—a, strip at least thirty inches wide should be trench-. od- for a hedge. Trenching should be so managed as to leave the layers of soil as they wero, i.e., the top soil should bo loft on top; poor growth would result if the order were reversed, even though manure were applied. If there is a grass covering to the surface tho turf should first "be cut; this should be chopped up, and bo placed between tho bottom, and top layer of soil, or it may be stacked and used for.top-dressing when tho grass has decayed. The site should bo prepared some weeks before planting, so as to afford opportunities for turning the soil over a few times until it is thoroughly broken up. Individual taste will always bo a. factor 'in determining what to plant as a hedge, but suitability to conditions should always be considered. A RELIABLE SPECIES. Eleagnus is probably the most reliablo of hedge pliurfs proper, but requires a good deal of clipping, and is not easily kept to narrow limits j it answers well for poor and dry soil. Laurestinus makes an excellent hedge in fair circumstances, and stands cutting back. Euonymus japoaica ■and English holly both do well if. they have -a good root run, and both submit to unlimited cutting. If at any time a hedge of either of these plants becomes too wide, tho face of the hedge can be I sawn off, leaving1 only bare poles, and provided the top also is cut off or tho entire face cut back, it will break again, and make a. hedge more densely furnished than before, because there'will be many more branches —in fact, if they were cut down close to the ground they would furbish' again. For exceptionally windy places, or for places near the seaside, two plants aie particularly suitable: these are the taupata and the karo, the latter ' being Pittosporum crassifoliuna. The natural hpmo of this plant is by the sea, it is unaffected by wind, and fairly rapid in growth. Holly is not often planted as a hedge in these parts, the impression being that it is of slow growth. This is true in so far as concerns the first few years, but it is fast enough when once it gets started. Space does not permit of mention of all the various hedge plants, but one other must be noticed. Cupressus Lawsoniana is the best of them all, but not for a. hedge of small size; it can bo kept to narrow limits for a. number of years, but -x ill not' respond 'to cutting back beyond growing shoots. This cypress is the "hardest tree we. have. I have known' it to be untouched by southerly blizzards that have scorched blue gums, pines, and macrocarpas, as well as every shrub. For a hedge that is intended as a broakwind, to grow rather larger thsui hedges usually are allowed to gro%v, this tree is unequalled. It is slow for two or three years, after that quite rapid enough. It always keeps its bottom branches, and will stop tho strongest wind.

A word as to the treatment of established hedges: Close planting- results in such a denso mat of Toots that they must seek moisture in the surrounding- soil. Soil should bo loose. When the hedge is planted on a filling the roots will have a good run; jjrass may bo grown close to them without injury. Insufficient rootrcom or competition of nearby trees is usually tho cause- of hedges doing badly.