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White and grey chalky substance on pots

Discussion in 'Issues, Disease and Pests' started by MrsJiminy15, Nov 7, 2016.

  1. Nov 7, 2016 #1
    MrsJiminy15

    MrsJiminy15 New Member

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    If you're following my thread in the Introduce Yourself forums, you know I'm in the process of trying to get two (of my four) Phals to rebloom. Some great advice was given that I need to obtain a big enough temperature difference to encourage new spike growths. Having recently examined my Christmas cactuses that are in full bud in our FL room (which is like a room that the previous owner created from a garage that has no air or heat), I figured why not putting the orchids out with them during the night and bringing them back inside during the day. I remember my grandma always told me Christmas cactuses need that temperature difference too, so I figured why not try it.

    Last night was the first time I tried, and this morning when I went to move the two orchids back into the house, I noticed their pots had all this white and grey chalk like substance on them. They didn't have that when I took them out there last night. They are both potted in clay pots, would that have something to do with it? The orchids themselves look unharmed, but the pots were a bit alarmingly. I wiped the chalky substance away, but now I'm wondering if I should continue to put the orchids in that room.

    As always, any info you can provide is greatly appreciated!

    Claypot1.jpg

    Claypot2.jpg

    Claypot3.jpg
     
  2. Nov 7, 2016 #2
    KellyW

    KellyW Orchid wonk Staff Member Supporting Member

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    When they are inside do you have them sitting in decorative pots? When outside were they as photographed, without a decorative outer pot?

    The white deposits are minerals from your water and fertilizer. Water soaks through the pot and when it reaches the surface it evaporates which is why terracotta pots feel cool. When the water evaporates it leaves the minerals behind. I suspect the stains were there before you put the pots outside but were damp enough that they weren't as obvious. The pots had a chance to dry a bit overnight and made the deposits more visible. Probably the deposits will be far less visible once wet. The greenish tint in the first photo is just algae.

    It should be harmless but does indicate you have a high mineral content in your water and you will need to thoroughly flush water through your medium frequently.
     
  3. Nov 7, 2016 #3
    MrsJiminy15

    MrsJiminy15 New Member

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    This was very helpful, Kelly. Thank you so much! When they're inside, they hang from a wooden basket near the window so they hopefully get plenty of airflow. When they were out in the FL room last night, I had them sitting in a box side-by-side (I was just hoping for cooler temperatures, not thinking of good air flow). I've never put them in a decorative pot since they've been repotted in the clay pots. Should I?

    When you say flush them frequently, should I flush them once a week when I water them? What's the best way to go about flushing? With moss medium, it's a bit tricky to let water run through them. Is it best to just hold them under the faucet for a period of time or let them soak in a pot?

    Should I continue to move them out in the FL room during night time to encourage reblooming if this has no affect on the plants themselves? And you're exactly right about the clay pots being cooler. I did notice that this morning. Hopefully I'm able to get that temperature difference I'm looking for. Too bad I can't tell what the temperature of the orchid is, versus it's surrounding area.
     
  4. Nov 7, 2016 #4
    KellyW

    KellyW Orchid wonk Staff Member Supporting Member

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    Not necessarily. I just thought that maybe that is why you hadn't noticed it before.
    Yes, just hold it under the faucet and let water go all the way through and out the drain hole. Do at least once per month.
    Yes, they need at least 10-14 days of the larger day/night temp differential to initiate blooming.
     
  5. Nov 7, 2016 #5
    MrsJiminy15

    MrsJiminy15 New Member

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    Thank you so much for all your responses. As long as I'm flushing them once a month, is it okay to contunue to use tab water or should I switch to distilled? I've also heard water from dehumidifier works too.
     
  6. Nov 7, 2016 #6
    carl

    carl Active Member

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    Depends on your tap water. Do you have an inline water softener? If so, you'll want purified water - the sodium load from a typical water softener will do more damage to your plants than teaching them JavaScript. Is your water hard? (In the liquid state, that is, frozen water is quite hard, after all ;)). Again, go purified. If it's considered soft, and not softened, phalaenopsis and many of the larger plants are fairly tolerant of tap water, although I usually use warm water from the tap, not cold. Flushing the pots monthly should be fine.

    I used to use dehumidifier water on my miniatures, worked great. It's basically distilled water - water condensed from the air onto the coils of the dehumidifier (provided those coils are clean of course). I now use reverse osmosis water for all my plants. Leaves look much better, shinier because there's so much less dissolved material to collect there, and less brown tips due to various things dissolved in the water. In terms of benefits to the plants, it was worth the buy. You can get counter top models that hook up to a sink faucet to make a few gallons at a time, all the way to industrial scale systems to provide domestic water for an entire town. The former is recommended, for the latter, you may need one in a few years, especially if you buy lots of seedlings ;)
     
  7. Nov 12, 2016 #7
    Dave The Scientist

    Dave The Scientist Active Member

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    It's actually lower average temps that cause spike initiation, not the day night differential (although a moderate day night differential of 5-15 degrees is good for overall growth and health of the plant. If you just get them down into the low 60s or high 50s for a few weeks, they should bloom.
     
  8. Nov 14, 2016 #8
    AnonYMouse

    AnonYMouse aka Ree, the not-so-stealthy lurker

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    Do you have it solely in sphagnum moss? If so, once a week water may be too frequent (you want Phal media to dry/near dry before more water. Ignore this if the conditions require it). Consider flushing based on the water TDS and Fertilizer concentration/frequency.

    I'm also wondering if the white is mold (relatively harmless). Wet, dark and cool is great for mold growth.
     
    Last edited: Nov 14, 2016