You could take a container thats big enough for your plant to fit into, like a 18gal storage tote. Place you plant and container that it's in, in to the 18gal tote or whatever you have and fill it up with cold water. Now go freeze 5-6 2liter bottles of water or how ever many you can fit in your freezer. Once frozen add 2 or 3 2liter bottles to the tote to keep the water in the tote cold in turn cooling your plants res. Just keep changing out 2liter bottles when thawed. It works OK for a single plant but you just need to figure out how long the bottles last. Good luck!