I am having some problems with the main stem breaking off right at the oasis line. It is happening in the Crazy Christmas, Marble Star and some in the Prestige. Under the mircoscope we think we some some phythium in thr stem, but the roots are excellent. These are bushy, 16" tall with some space still between the plants. Any thoughts or ideas?

Hi Deke -

If you see something that makes you suspicious of a pathogen you may want to consider phytophthera that can infect any part of the plant but most often the stem and right at the soil line. If it is an early infection the roots could still look healthy. The only way to know for sure would be to have the material tested.

Phytophthera usually begins as a brown stem canker and the pith cavity and vascular area will also turn brown. Under humid conditions and warm temperatures black streaking can also be seen and the infected branch or entire plant will die. The disease is favored by high EC and overwatering. Fungicide drenches are necessary for control and rouging any suspicious plants as the fungus is spread by splashing water.

What have you applied for fungicides?

Do you think it could be a stem breakage situation? Prestige usually doesn't have a problem with stem breakage but even Prestige can succumb to breakage if there are more breaks than the plant can support.