could we see the whole plant...

all the damage looks like shipping damage.. probably before you got it ..

where are you.. big city name ... socal is a bit vague.. to me anyway ...

if the plants blow over in wind.. i hope the new transplants are not in any sun .. until they root in ... did you moisten the media ... before use?? .. if not.. that might be a reason you cant tamp it down enough to stabilize the plant.. again.. if we see the whole plant and pot.. we might be able to intuit something in that regard ...

ken

@Ken Thank you for the response! I live in Huntington Beach, about 3 miles inland. Here are the full pictures of the Gardenia and Plumeria. I also included a close-up of one of the Plumeria leaves because it has gotten brown spots in the last few days. I have been keeping it in the sun because that's what I thought it liked... should I move it to the shade for a while?

I used a succulent potting mix when repotting and I can't remember for sure, but I think I just watered the plant well afterwards and didn't pre-moisten it. I did tamp it down pretty well, but I probably could do it a bit more firmly. I was just afraid of packing the soil too tightly since I read that they need loose, well-draining soil (that's why I used the succulent mix). I was thinking about adding a layer of pebbles to the top to help secure it but wasn't sure if they would get too hot in the sun... also I could plant it deeper in the soil, do you think I should try that? I wasn't sure how deep I could get away with, so I tried to keep it the same depth as it was in the original pot.

Update on the gardenia: I sprayed a copper fungicide the day after I started this post and it seems to have helped. Some of the leaves still have spots and of course the curled leaves and caterpillar damage hasn't gone away, but overall I think it looks healthier and there is lots of new growth. It rained quite a bit yesterday as well, so that probably helped too. I'm thinking I'll keep spraying it regularly just to be safe.