Questions of the Week: May 11, 2017
I sat down to write this part of e-gardens and no one question came to my mind. However, three jumped up together, shouting and holding their hands up to be noticed. So I’m going to give you the short-form answers and appropriate links for more details.
“Neil! What are these red spots that are all over the leaves of my Indian hawthorns and redtips?”
This is Entomosporium fungal leaf spot. Here is what I have in the FAQ pages of my website. This is about the disease on redtip photinias, but it also attacks the closely related Indian hawthorns. https://neilsperry.com/faq/what-is-killing-my-redtip-photinias-their-leaves-have-purple-spots-all-over-them/
“Neil, what is killing Italian cypress trees all over town? What can be done to stop it?”
Seridium canker, the same awful disease that ruined Leyland cypress trees five years ago, is responsible. Here is the story we ran on it here just a few weeks ago. https://neilsperry.com/2017/04/question-of-the-week-1-april-6-2017/
“Neil, why is my St. Augustine so slow greening up this spring? Grubs? TARR? Brown patch?”
I said when I answered this that a few weeks ago here that there are a lot of misdiagnoses for St. Augustine issues right now. So I just listed them all with guidelines of how to distinguish one from the next.
Before I give you that link, however, one late-breaking note from plant pathologist Dr. Phil Colbaugh, retired from the Texas Agricultural Experiment Station. Phil sent me the alert late Sunday evening that Take All Root Rot (TARR) is, or soon will be, moving into the summer phase (my term). It attacks grass roots in alkaline conditions when the soil is cool. As things warm up, however, TARR becomes inactive. That is starting to happen now. That means that application of peat moss probably won’t be of much help much longer. You’d be better off filling in areas that the fungus killed with healthy new plugs.
That said, here are the St. Augustine diagnostics. You might want to print them and save them.