Mine is on an east facing wall and thrives on neglect. It grows with very little water once established - after the first year. It can easily reach 8 feet in height.

My yard long hedge was indifferent to water. It got some water where it was near the vegetable garden, no water along the rest of its length. Part of the hedge was under a large pine, part of the hedge was in full sun. It's a pretty indestructible plant.

That's great to hear. Thanks for the feedback.

Oh I more question. If I want a privacy hedge, how far apart do you recommend that I plant them along the wall?

This is a tough plant. I've grown them in bright shade (the surrounding trees got large and shaded it), and they did fine. Some sun seems to be sufficient. This is a photo of one of my young wall plantings. It was planted from 1 gal. containers three years ago.

As you can see, we cut out tiny holes in the sea of concrete (10' intervals). Most plants would have protested at such abuse; in fact the bougainvillea that was in them first failed to thrive. Each plant got one drip emitter. Our soil is very sandy; they get watered with everything else about every 4 days in the summer, but would be fine with less. Emitters have gotten displaced for a couple of weeks at a time, unnoticed, because the plant didn't show any ill effects.I prune these to not exceed the top of the 7.5' wall. But they would be happy to grow taller.

Cool. If my wall goes up to 6ft. do you think the vines will go up an extra 2ft on their own without support?

how do you prune the lavender star flower tree to start creating a hedge

How big is it now? Do you have a picture? It starts like a lanky shrub.

Night here, so I cannot take a photo now. But it is basically the same size since I keep it espaliered, though it has filled in more to better hide the block wall.

My plants are espaliers, not grown in hedge form. The growth is against walls and is allowed to only reach about 10-12" in depth. This plant is one of the easiest to start as an espalier, because of the flat branch pattern it naturally produces. You can see in the photo below that the side branches grow flat to each side of the stem.

Here is another early photo of one of my Grewia espaliers. I attached 3 horizontal wires to the wall, about 1.5 - 2' apart. Then I tucked the branches behind, or occasionally tied some to the wire, then pruned the few that grew the wrong direction.

Once the plant gets some good growth-supporting roots established in the ground, the branches quickly grow almost like long suckers, but with the flat side branching. You can see how the shorter, denser lower growth switches to the vigorous longer canes at about the halfway point in the photo below.

This plant practically begs to be espaliered, although they could easily be allowed to grow in a more hedge-like form. Espaliers do require regular pruning upkeep. For a hedge, I'd probably top the canes more to encourage more of the plant's energy to go into the side branching. It is a robust plant, so if the space is limited, even a hedge will require regular pruning maintenance.

I love it the way you have it. When I had it grown against a fence in the same fashion it took very frequent trimming to keep it slim. I did grow a single plant as a free standing shrub at a different house. Much easier as I could ignore it for longer. I would only shape it when the long branches would lank out the way they do. Not sure why it isn't more commonly used. I've even considered anchoring it to the ground, though I've yet to try that. I was thinking a ground cover to be viewed from a distance.