deep watering trees

[AndrewPatrol]

We have trees in the 5 - 10 metre range and because of the drought conditions here ( and most other places) I have been thinking about watering them (usually we dont bother and they're fine) but I dont want to just surface water 'cos it'll encourage the roots to come to the surface. One idea I been thinking about is somehow getting one of those black pipes down in the ground a bit but how do i get it in there ( especially without hitting roots) and how far? Any other ideas welcome also.
TIA
andrew

[DavidG]

Use a post hole digger.
If you cut the roots it will only stimulate new growth, especially with the moisture.

[Bleedin Thumb]

If your trees are 5 -10 m high the if you want to deep water them you will need a hole 5 -10m deep or even deeper.

Do you have a drill rig handy?

Deep root watering may be good for establishment but once a tree is established you shouldn't need it.
If the tree fails then it was the wrong species for the position or had a flaw. IE grown from a cutting not seed or perhaps had been root-bound before planting out, or just bad luck who knows, but at that those depths the soil almost always contains moisture that the roots can access.
I'd just let them be - if they start to stress you will know, then just give them a flood.

[rhancock]

What Bleedin Thumb said. Are the trees showing signs of stress? Any gardener you talk to will tell you they have to sort out more plants suffering from overwatering than anything else. Fruit bearing trees might need water when they're setting fruit, and as BT said, something exotic planted in the wrong climate might struggle. If you want to help your trees, create a bund (shallow dish) around them out a little past the drip zone - the widest part of the tree - and mulch it heavily with anything you can get hold of. Just keep the mulch away from the trunk or you'll get collar rot. Your worry about bringing roots to the surface is unfounded - the tree will do whatever it needs to get the water - and usually thats deeper. If your trees are showing signs of stress, then make the bund, fill it full of water, then mulch well.

Just remember, trees are designed to withstand drought!