I'm not familiar with that plant, but when plants are moved, they ofter sulk for a while. I would just keep your eye on it and see if it recovers.

I'd agree most likely suffering from some transplant shock. In the northern hemisphere, July is not an optimum time to move broadleaf evergreen shrubs. Fall or late winter/early spring would have been better. Just keep it well hydrated - it should recover.

Planted 25 24" tall Choisya Ternata plants last spring. Six are not doing so well, three are wonderful, the rest okay for the first season. The six have yellow, droopy leaves- started to yellow towards the fall. Any ideas for spring?

A few possibles: when you made the new hole for the plant did you thoroughly loosen up the surrounding soil - or make a 'just fits' hole? If your soil has a fair bit of clay in it - it might be holding the winter-wet and stopping air from getting to the roots. That can be worse with a 'just fits' hole.

When you dug it up - did it come with a big ball of roots - plenty of small roots - because they're the feeding roots, usually. The big ones are often there as anchors but they don't forage as well as the younger and smaller roots.
If you know you lost a lot of the root ball - then you have to also cut back the top - to keep a balance. Otherwise the leaves are losing more water than the roots can supply and the plant drops leaves (or turns them yellow) to conserve water.

Also: depending on how your weather has been - lots of evergreens also have an annual (or twice yearly even) shedding of leaves. In the unlikely event of a long dry spell that leaf drop can occur in mid-winter.

If you have a garden that gets hit with wind gusts - provide your transplant with a supporting stake, and a temporary windbreak. An old sack or sheet between two stakes would probably be enough unless you have extreme winds. Leave it in place for at least six months - time enough for the new roots to settle in to the soil and hold the plant still.

If you know you get a dry spell in spring be prepared to water the ground around the plant AND the old root ball. Slowly pour on about 10L once a week. Never assume that enough rain has got past the leaves to wet the ground.

And take some cuttings to try for replacements in case you have a 'lingering death' situation. Sometimes a plant puts on a burst of enthusiasm, flowers like fury - and dies. Sigh. (If memory serves, Choisya is usually pretty easy to strike in sharp sand or pumice grit.)

I'm sorry, jimsbiz. I didn't notice until I'd finalled the post that you had hitched on to an old post. It's usually better to start your very own thread.

Check your soil as a starter. If you know that your plants had good roots when you set them out - and the soil had been amended, then drought is a first possible.

If you mass planted them your watering system might not be reaching those which are yellowing. Or it might be drowning them.

Choisya is really tough once it's established but it does prefer good drainage and appreciates mulch to conserve moisture at the roots.

If the watering is fine (you dug down and saw there was moisture six to twelve inches down) look at soil quality. You could lightly add some old compost (1"-2") and/or use a weak organic tea fertiliser. Half strength or less every two weeks. Like very weak tea - pale brown and see-through. If the plants aren't well they cannot cope with full strength food. It will probably burn their roots and leaves.