[Cynthia, Prescott, AZ]

Clara, I had 64% shade cloth on a glass greenhouse in southern California. With losses in the glass, especially when dirty, I expect I had about 3000fc. The reason the Phals had a problem was because this is much more light, about twice, what Phals get in the wild, and as a result they were under stress. Stress means that they are weakened and become particularly susceptible to pathogens. I have had a situation recently that illustrates this. I was using damaged neem oil which the sellers were storing out doors with temps down to at least 10F. This is a no-no according to the MSDS sheets. The result was that the plants were severely stressed, with some even having direct and immediate damage from the neem. But those that didn't show damage directly were still badly stressed, and the result was that I had, from bad to worse, mottled leaves, failure to bloom, a virulent case of fusarium in many plants, too many to count, and just slow withering away. All these symptoms came on weeks to months later, hence the inability to recognize the cause for several years. Most plants are on the mend now, but a few are still slowly going down hill in spite of a ton of systemic fungicides and a systemic bactericide. I even had rust on a couple of plants, one of which I saved. I would say you would be well advised to cut your light back to at least 2000fc.

Martine, you probably do have enough or more than enough light. Even tho you may be further north than Clara, we have to allow for the fact that many of the east coast states get a great deal of overcast which you may not be getting.