Heat Pack Experiences?

[19 Below!]

Living here in MN, and wanting to get some more orchids, some sellers use heat packs, some insulation and heat packs....but I have my doubts if they really work in below freezing weather? I wouldn't order until temps were in the thirties at least...but just would like your input....

[Roberta]

Heat packs add maybe 15-20 deg F to ambient, for maybe 48 hours. (rated for 72 hours but by that time they're cooling off) So they won't help for really serious cold... they'll help for temps that are somewhat below freezing for awhile (like maybe 25 deg F) but not the serious cold that you are experiencing. Definitely wait. If you are anywhere near Minneapolis, you should contact Orchids Limited (they are in Plymouth, MN), don't think they are open for drop-ins but perhaps by appointment. They also don't ship until it is safe - according to their website they won't start shipping until Feb 6, and then with heat packs. For any other vendors as well, be sure that they understand temperatures. The good ones will set your order aside (so if you want something in limited supply you'll get it) and only ship when it is safe.

[Ray]

I used to use 96-hour heat packs, trusted them only with 2-day shipping (which means they were typically active for 60 altogether), but they need to be used properly.

They consist of iron filings, carbon dust, and salt. Once exposed to air and humidity, the iron starts to rust, generating heat.

That means that the box must be ventilated to allow air in, and there must be a moisture source. Since you want to ship plants dry in winter, I saturated a paper towel, put it in a zip-lock bag and poked a few holes in the bag.

Plants were wrapped in shredded paper then sheets of it to insulate them. The heat pack, moisture source and plants were placed in an insulated box (with 2 x 1/4” holes in 4 sides.

[Roberta]

Against 19 below zero F? Nothing is THAT good. Need to wait for warmer weather.

[19 Below!]

Well, we aren't 19 below here always, actually minus 24 last night. We should be in the 30's this weekend and well into next week with 40 one day. Normal this time of year is 25. Just SO cold!

We are a couple of hours away from Orchids Limited, I have seen their website. They only allow in person pickup, no inside sales. I will email them about delivery to our area.

I think ordering from FL, TX or other states might be pushing the envelope even with heat packs. I also worry the heat might damage some plants.

I covet some plants on other websites, but feeling it is wiser to wait until "spring". Thanks

[Ray]

I’ve shipped flowering plants to Alaska in February.

The heat packs can reach 120 degrees, but the question is how many BTU’s they produce versus how many are lost. With a very well-insulated box, that might cook them. In a poorly insulated box, with low outside temperatures, they’d freeze. The shipper’s goal is finding the sweet spot in between.

[Roberta]

Sounds scary to me...

[estación seca]

If your shipment is delayed the heat pack fizzles out and your plants popsicleize. Hausermann's near Chicago and Olympic Orchids near Seattle won't ship during cold weather. I suggest you take this opportunity to practice your patience.

[tmoney]

can you order now to reserve the plants you really want and have a ship date set for later?

[19 Below!]

I think I will take this time to learn. Plan is to have more orchids in bloom next winter. So I will try to learn about Phals, Oncidium and Tolumnia. I am also thinking about ordering some virus test strips. Maybe I should batch test what I have to be sure I don't start out on the wrong foot?