Cooling Darlingtonia Pots with the Zeer Pot Method: Sand vs. Perlite

QUESTION: I recently read one of the Q&A with you putting up the link for the tube video of using 2 clay pots with one inside the other & filling the space with sand. I was wondering, being that CPs like TDS low, what are you supposed to fill the space between the pots with? Being that regular sand has high TDS & silica sand is increasingly becoming alkaline & smaller grains—not to mention hard to find. I would like to use this for Darlingtonia. Will it work with perlite?

ANSWER: Hi Michael,

Since Darlingtonia are best only top-watered, and not sitting in water trays, a bit of mineral content isn’t going to be a big issue as long as your sand isn’t from limestone or marble sources. Also, if you are going to pot them in the Zeer potting method, the sand would be on the outside of the Darlingtonia potting medium, and the net water flow would be away from the plant’s roots. In the Siskiyou mountains in Southern Oregon and Northern California Darlingtonia are often found in more alkaline soil conditions in serpentine habitats, so the pH isn’t that big of a deal to them.

If you aren’t comfortable using sand you can get in your area, I don’t see any reason perlite wouldn’t work. I haven’t personally tried it, but perlite does conduct water very well, so it’s possible it might work even better.

Good Growing!

Jeff Dallas
Sarracenia Northwest
https://www.growcarnivorousplants.com

---------- FOLLOW-UP ----------

QUESTION: In the video the man tapes the drain hole, so how do you water the Darlingtonia if the hole is plugged? Won’t the pot just flood because the water has nowhere to go?

Answer

Hi Michael,

Instead of taping the holes, use a sphagnum moss wick similar to how Adrian Slack shows in his books for “Slack Potting” of Drosophyllum. This would also allow you to sit the Zeer pot assembly in a small amount of water and still get the cooling effect. If the outer pot stays damp, you should get quite a cooling effect, especially on less humid days.

Good Growing!

Jeff Dallas
Sarracenia Northwest
https://www.growcarnivorousplants.com