What is this white powder on my pots?

Another question for Douglas. I have a white powder on the pots in my greenhouse. The containers were brand new and the plants were potted for a little over a month. I've seen mineral buildup on terracotta pots is this mineral deposits? If so, why only on the bottom portion of the pots?
q what is this white powder on my pots, cleaning tips, container gardening, gardening
  10 answers
  • 360 Sod (Donna Dixson) 360 Sod (Donna Dixson) on Feb 14, 2013
    I have worked in nursery all my grown life and I have never seen a pot 'band' so perfectly. It almost looks like a tape line of some kind. Can you get a close up of the white area? Did you purchase the pots new in a string?

  • Douglas Hunt Douglas Hunt on Feb 14, 2013
    I agree with Donna that this looks much more like a manufacturing/packaging issue than anything else.

  • Jeanette S Jeanette S on Feb 14, 2013
    I can't believe any natural substance would grow in a straight line in a perfect match in height to the one next to it...??? Just won't happen. It is a "thing" with the pot manufacture...has to be.

  • CAROL H CAROL H on Feb 15, 2013
    Jeanette, Any ideas on how the pot itself would contribute to the white powder?These were brand new clean pots with string attached. The white substance is powdery and I can wipe it off with my finger. So... Anyone have any other thoughts? Do I need to call in MacGyver, LOL!

  • Douglas Hunt Douglas Hunt on Feb 15, 2013
    Possibly some sort of talc the manufacturer puts on the pots to keep them from sticking together?

  • Tammy@Deja Vue Designs Tammy@Deja Vue Designs on Feb 15, 2013
    Maybe they had been sat in a pan of some sort and watered....the minerals in the water would do this in a straight line if they were sitting in it.

  • CAROL H CAROL H on Feb 15, 2013
    Mysterious white ring solved - After further investigation I found that everything sitting in the floor of the greenhouse had the same ring, so when all else fails, I ask my husband if he had any idea what could have caused this to happen. He said that it had to be from standing water - makes sense. We have had a tremendous about of rain in Georgia, which must have flooded the greenhouse up to the level on the pots, heater, etc. He's a smart cookie. Now we have some grading to do.... Thanks so much for all the feedback!

  • Douglas Hunt Douglas Hunt on Feb 16, 2013
    Whew, at least one mystery solved.

  • Tammy@Deja Vue Designs Tammy@Deja Vue Designs on Feb 16, 2013
    Well...I was close.

  • Jean dudley Jean dudley on May 04, 2015
    Seems like it was sitting in water and the minerals had adhered to the pot.