Temp dropped in Greenhouse to 35deg f - will I lose my orchids?

[scottfar]

Nothing has wilted as of tonight (about 18-22 hours after it happened) I guess I'll know in a few days...

I've seen a couple of min/max temp alarms in a catalog or two.. but they were all expensive (over $200). Anyone know of an affordable one? I haven't really looked online.. but its a priority now. I've seen some that even CALL you .. that'd be cool.. but really unnecessary since I'm usually home by the time the temps really drop...

[Bikerdoc5968]

Temperature problems was prbably most serious concern when I put up my GH this past summer. The GH I purchased came with an electric heater and thermostat (pic), but electricity is costly in Michigan and I purchased a natural gas heater with self-contained blower ___. Of course this means installing gas lines, etc. which I did prior to the GH placement. Even if I have a power failure the gas will still run without the fan circulation but that is better than no heat at all. I am using the electric heater as back-up just in case I have total NG failure.

[Tmai]

Good luck, Scott! I'm sure it's not as big of a disaster as you must have feared. We love our 'chids so much that we fret a lot over them and worry that we may not be the best parents! But mostly they still love us and forgive us when things happen. Let us know how things turn out.

PS - wow, biker, that's some set up. I'm not mechanically inclined (but I did control chemical reaction for 36k pounds of butane at one time in my life - really). That looks like a really great set up. Are there any issues with combustion gases from nat gas or propane set ups affecting the plants?

Tami

[Bikerdoc5968]

So far, I haven't noticed a problem. As you know combustion of methane is water vapor and carbon dioxide. This NG heater is vent-free. There certainly could be a concern that if something should go wrong with the burning of the gas that carbon monoxide would be a by-product but so far so good and at 20,000 BTu's for a 8 x 15 GH is nice. The downside to water vapor as a result of burning the gas is that in my cold Michigan weather, I get LOTS of condensation on the inside and lots of water dripping on the plants

[scottfar]

UPDATE: Nothing has died ... a few lost back bulbs. Several of the cats (maybe a dozen) are showing REAL signs of stress..their leaves are very thin, all wrinkly and just don't look good. BUT almost ALL the cats are showing AMAZING new growth... almost every single one shows emerging new growth... Started watering a little more often, kept the temp more moderate and added very diluted fertilizer every time I watered. Its been 10 or 11 days ...

not convinced the growth spurts is due to the chilling ... or if its just natural this time of year or is a result of them being put into the greenhouse (they were in there a few weeks when the temp dropped to 35 degrees).

All the Phals seem fine. So... I'll let you know. One even had blooms which made it through but dropped a few days later...

Thanks for everyone's advice. I've ordered an inexpensive temp alarm. Will be investing in a gas heater and a propane backup once I get my REAL greenhouses set up this spring.

Scott

[Brutal_Dreamer]

...Thanks for everyone's advice. I've ordered an inexpensive temp alarm. Will be investing in a gas heater and a propane backup once I get my REAL greenhouses set up this spring.

Scott

Glad to hear everything is fine! Keep us updated on how things progress. I bet you will really like the temp alarm.

Cheers,
BD

[Piper]

Hi Scott,

I've been slow to find this thread, but I'm glad things seem okay! Phals will definitely blast their buds or recent blooms with a temp change. Sounds like your Catts are just pouting, but who can blame them - they're from warmer climes.

The wholesale slaughter occurs when you drop below freezing. When living cells freeze, they rupture cell walls, etc. and that's not recoverable. The tissue damage from freezing is massive and permanent. That's the disaster you want to prevent. If you have cold intolerant plants, a temporary dip like you experienced may cause some hardship, but freezing the plants will kill them quicker than anything.

Good luck with your greenhouse! It sounds like you're doing all the right things!

McJulie

[scottfar]

Just left the greenhouse... everybody (orchids) still look stressed... starting to show a little more about two weeks after the temps dropped to NEAR freezing (35 or so). No one has outright died. A few more back (and one new growth on a cat) have turned yellow and died... but there is sooo much new growth. New roots, too. There are even a few spikes!

One question: do you think the wrinkling of the leaves/stress is a result of damage/cold to the leaves or damage to the roots? They look like the potting medium is completely bad (have seen that in commercial greenhouses)... but the potting medium is fine.

Also - have been watering MUCH more... almost daily to keep the medium(s) moist. Not sure if this has anything to do with the cold or if its keeping my fans running 24/7 (have an oscillating fan on 24/7 on low). The same orchids that I was growing on a windowsill and only needed watering every 12-14 days now need watering every couple of days. More evaporation in the greenhouse?

I'm also watering differently... I used to soak each one repeatedly in the sink now am using a hand-held sprayer... that I use to water. Maybe they just need a good dousing? Any ideas?

Thanks again!

Scott

[Ron-NY]

Scott, don't over water! If the humidity is good, you shouldn't have to water more than 2X per week in the greenhouse except for mounted ones. (actually, during these low light days of winter, we usually water one time per week except for seedlings which stilll get 2x per week. Over watering will cause root rot and that will cause leaves to dessicate. Cold damage usually looks like blackened areas on leaves. What type of floor do you have in the greenhouse? We water with a hose that has a sprinkler wand attached to the end. There are fans running 24/7

[scottfar]

I really don't think I'm over watering... just a different way of watering. Before they'd get several good soaks under a running faucet.. and now I'm using a sprayer.. so obviously not wetting the medium enough.. but that said last week I soaked every orchid for about 3-4 minutes.. and medium STILL dried out very fast. Maybe its the fan.

Overall everything is good.. .cept we had ONE HECKUVA storm last Friday..and was w/out power from 3am Friday to 9pm Sunday. I had an emergency propane heater... but temps dropped to around 55 degrees for several hours before I got it up and running.. plants seem fine.. but about 25 orchids in full bud blasted their buds... damn shame.

Did a LOT of repotting.. they obviously needed it. But all the pots I repotted nearly 100% of the roots were dead... could this have been from the cold? I know I know.. overwatering.. but I don't think that was it...