The soaker hoses are fine, Ma used them for decades on roses and I used them till I got tired of having to drag any more hoses around than absolutelynecessary.
I water my vines, depending on year squash, watermelon, etc. overhead.
Leaves sagging is normal, but after I water the leaves no longer sag.
I have never had a problem but when I do it, with few exceptions, like the extreme drought { this and last year } , once a week for one hour or so.
I usually have rain gauges out so I have an idea how much I put down.
I do mulch as much of the garden as possible with leaves, hay or straw.
What Stone said about the soil IS very important; I have good soil , in both of my gardens with good drainage, but still at times add what ever mixture of a boughten concoction of soils strikes my fancy out of curiosity. ( I also roto-till in old potting soil , from the other half, when I have it, which does make a difference.)
I use a pointed or flat sand shovel to make the hole, having a spade also can be handy, but, make sure to loosen the soil the bottom of the hole, well, also, even after tilling.
I make the hole DEEP and wide enough so the roots will be dealing with that concoction for most of the summer.
