I have a few rookie questions about winterizing irrigation systems. When do you start blowing out lines? Do you wait until you are expecting a prolonged period with below freezing temps? Or do some of you start with the first frost? Do any of you have a "magic number", say line 20 degrees before you begin winterizing? This is all new to me. But common sense tells me that I shouldn't have to worry about winterizing for another month or so. We've had frost already. Temps in mid 20's at night. I feel that since the lines are buried and the ground temp is still fairly high that there is no danger yet. Plus daytime highs have been in the 50's with 70's forecast. My thinking is that until we start having sustained frost every night, and daytime temps start dropping and staying in 40's, that will be the time to start blowing out lines. I think this may be a good money maker. Very easy work, all you need is a compressor. What are you charging? Do you base price on number of irrigation stations? Do you adjust price if the job is a regular customer, or a one-time job? I'm thinking of doing some direct mailings targeting this. I appreciate all replies, thanks.