I have three Carolina Jessemines planted. They have excellent drainage and are provided with trellises for climbing. They prospered well up until about three weeks ago, when two of them have turned yellow in a majority of their leaves. The third, which is some distance from the other two, had a brief stint of yellowing, but now that's gone. These two have signs of new growth, but clearly, it's slowed. Suggestions?

Try using some liquid seaweed, it will help them handle the summer heat. Also give it a little bit of nitrogen.

Mine had some some yellowing and once I gave it some Ladybug 8-2-4 it perked up nicely and has put on some good growth.