I live in Orlando, FL (zone 9). I currently rent, but when I do buy a house, it will have a yard big enough for my fruit trees (which are currently potted). I have exotic plants like imber (mangosteen), breadfruit, sugar apples, jaboticaba, pitagnatuba, rollinia, canistel and more. I hope to be able to afford to build a conservatory, and I am open on converting an outdoor pool into a bed for my trees.

Even being in zone 9, the winters get too cold for some of my plants. I was trying to think of ways to warm up the soil. Our winters rarely dip below 50, but in very RARE cases have gotten to the lower 30s.

I was brainstorming possibly inserting metal buckets into the yard and when it gets cold, filling them with water and using bucket heaters. I heard there are bucket heaters that shut off if the water drops below a certain level (fire prevention). When these buckets were not in use, I would drain them and use a plug to cover them.

I'm just throwing an idea out there. Any thoughts or better suggestions?

Some bucket heater links:

http://www.bestrideever.com/Submergible-Bucket-Heater-1000-Watts-item16.aspx

http://www.hardwarestore.com/bucket-heater-513689.aspx

http://www.moorepet.com/Nelson-Blue-Devil-Electric-Water-Bucket-Heater-p/nelson-10202.htm

http://www.valleyvet.com/ct_detail.html?pgguid=2e87c5d7-7b6a-11d5-a192-00b0d0204ae5