Plumbago can take a whole lot of heat! It could be from too much water? Mine seem to thrive on 'neglect'. And they bloom very well.

Dancey

I had some planted in a location that was too moist and they also did not make it. I replanted in full sun in a well drained location and they are doing fine. They need full sun and well drained soil. (comparable to where you would plant verbena. Maybe you have had too much rain this year?

Too much water may be the case. We've had so much rain, but we've also watered that bed lately. When the plumbagos were in pots they would wilt in 48 hours if they weren't watered, so we got the idea they needed a fair amount of water. Maybe the new rule of thumb should be...if they aren't wilting, don't water?

Mine don't do well either. There seems to be some blight that cause them to die back as soon as the weather turns hot and humid. Wet weather probably makes it worse.

plumbagos thrive on neglect. i tried babying a couple of mine and the started dying off. i left them alone and they came back.

The summer rain itself shouldn't do-in the plumbagoes. Have the leaves yellowed markedly prior to the plant dying? What is the soil's pH?

Another aspect to check is if the soil they are planted in is FAST draining. This could be where the rainy season is finally doing the plants in. If they are planted in very rich, clayey soils, the roots are literally suffocating.

Thanks for all the good advice. We were overwatering. Actually, mom was overwatering, but I won't go into that! The "dead" one has put out one new shoot and the sick one is looking much better. The bed has 16" of good soil mixed with some sand but below is gumbo. A bit like planting in a bathtub I guess. I think they will make it now, if I can keep her hands off the hose!
Thanks again.

i had two that were struggling in the original pots i planted them in. seemed they were outgrowing the pots. i replanted them both into a huge pot thinking they would do well and instead they seem to be thinning out tremendously and now turning yellow and no more flowers. what do i do to save them?

I have a plumbago hedge in front of the garage here in South Fl. Half the hedge is gorgeous, but the other half is dying off. It is the second round of plants in this position. Can't work it out. The ground seems to drain well, although that part is right by the downpipe from the guttering. What to do?

Maybe like the other folks said it is getting too much water. I have one around a tree and on one side of the tree it gets lots of water and on the other side it doesn't. And of course you can!