The best thing to do, if you haven’t already, is to dig Josef up and take a look. With your clay soil and heavy rainfall, I suspect you’ll find that the roots are in trouble. The symptoms are typical of an evergreen plant that has lost the ability to transport water and nutrients up into the leaves because the roots are damaged. Healthy roots should have light-colored, fleshy tips, not black ones. If you are able to catch it in time, potting it up in a container with fresh potting soil would be the best thing to help it recuperate.
Following Rhonda’s advice, I’m going to do just that.If you click the image above to enlarge it, you can see growing points at the base of some of the stems. This plant hasn’t given up; it wants to live! After digging the plant up, I brought it near the closest hose to be washed off. Now it’s time to perform surgery. I cut off blackened root tips, and if a root tip looked fine, but there was some black further up the root, I cut off the root so that the black part was removed. I also trimmed off any part above the roots that was black, such as bits of stem. And I trimmed off any leaves that were brown. Then I potted up ‘Josef Lemper’ in potting soil that did not have hydrogel granules or anything else designed to hold extra moisture in the potting mix. He is now resting comfortably on the porch. As Rhonda suggests,
When you dig it up and replant it, you should water it lightly to settle it in, then not again until the soil surface begins to dry. If you are still deluged with storms, you may want to put it under cover where it won’t be super-saturated again. Don’t fertilize until it shows signs of new growth. Then say kind things to him and wish him luck. He will either make it or not at this point.
Right now I have the container under the cover of the porch roof so it won’t get moisture unless it comes from me, and gets about a half day of sun. I’ll keep you posted on how he’s doing. In the meantime, the hot, humid, and rainy weather pattern has finally left us, and I hope all the stressed plants have a chance to recover.