On a tangent to the original query: if you're game, you might try pleaching (grafting) your hedging plants--those of the same species. Normal hedges, where individual plants are planted quite closely together, compete with each other for nutrients as they grow. So if one plant sucks more water from the ground, it leaves less for its neighbour, which suffers. However, I've read that if the plants are grafted, they act more like one plant. If one gets more moisture, that moisture is circulated throughout the entire body of grafted plants and helps make them all stronger. Dunno if the theory works in practice, but it might be fun to try. (I intend to try it when my hedglings get large enough for their branches to cross.)

Photinia, although usually seen pruned, is more than happy to be left in its natural state - perhaps it might not be as dense. I have one with only the lower growth trimmed back to its multi trunks (I just rub off any new growth), the remainder left as is, and it forms a very attractive small tree with a rounded top. The new growth (leaves and stems) ranges from light olive green to bright pink, depending on the variety, while the mature leaves are mid green - very attractive but not what I would refer to as "darker foliage". Another suggestion would by myrtus communis (the common myrtle from the Mediteraean). This forms a dense, rounded shrub with small dark green leaves. Its very pretty small white flowers are followed by bluish black berries. I've put in a link with a photo. Cherry laurel, photonia and the myrtle are all drought resistant once established, are frost hardy, provide dense foliage to the ground, and grow into a nice form without the need for pruning. I understand your point regarding pruning - I used to have a tall cotoneaster hedge as the side of a driveway. It was only about 5 metres in length - why hasn't someone invented a self levelling ladder? - and had to be pruned from both sides. And, if you are aiming for 3 metres, you won't reach the top of the plant on a 6ft ladder - I know from experience that the taller the ladder, the more unstable they are. Both the cherry laurel and the myrtle seem to easily strike from cuttings (that is, I've been successful). Here is a link that might be useful: http://www.plantoftheweek.org/week125.shtml

I dunno, sometimes I type out a response/message press the right butoons, come back the next day and it hasn't worked. My fault or this sometimes unstable site? Anyway, I agree with Ted except I thought that black scale was 'hard' scale, not that it makes any difference the remedy is the same. My reference (Encyclopedea of Aus Gardening) says that native honey-eater birds usually keep the scales under control. Do you have any of those about, pennyw? B.

Don't want to burst your bubble, but all trees drop their leaves, including conifers. I have a row of some sort of conifer that has little round seed pods. In addition to the leaves that fall naturally seemingly all year round, they are also incredibly messy whenever it is windy and gutter cleaning is a regular chore. The hard round seed pods are a real joy to walk on - hurt muchly if you are bare foot, very easy to turn your ankle if wearing shoes. And if that isn't enough, in spring the trees flower. And discharge huge amounts of pollen - yellow dust which covers everything. And do remember that these trees are not going to stop growing at 3-4 metres. If it were my swimming pool, I think I would prefer a deciduous tree that dropped it's bundle once a year. If you have a neighbour on the other side of the fence, do remember that these trees are also going to affect his/her gardening in the area of the trees.