substratum
Shohin
I live in north Florida/8b, where we do get overnight freezes in the deep of winter. In Winter 2018, we had more cold nights than usual, including a solid week that it didn't go above freezing, but that is truly an anomaly. Typically, people around here plant cold-tolerant varieties of citrus on the south side of the house, in full sun. If you have questions about what is tolerant for your area, I recommend contacting your local Agricultural Extension Office. Around here, if we are going to get a hard freeze, taking minimal steps to protect them, like covering with plastic or a blanket, maybe even a heat lamp on the end of an extension chord, is usually enough to protect them, because the freezing temps usually don't last for more than five or six hours, and the sun chases them off quickly in the AM. I know a few folks that have citrus trees, lemons or key limes, in-particular, that have them in big pots, and they hand truck them inside to a garage or shed on those hard freeze nights.
Down in the orange groves of central and south Florida, they use orchard heaters called "smudge pots," which are low-tech metal tubs with a smokestack. I think they burn fuel oil. When they light those things up across the grove, and they get fired up good, it sounds like jet engines. They shut off the air intake to turn them off. I have a friend that used to fire a couple up for his outdoor winter parties, which he'd place around the perimeter of the event, and it provided a remarkable amount of heat if the wind wasn't blowing too much. They do stink, though.
Down in the orange groves of central and south Florida, they use orchard heaters called "smudge pots," which are low-tech metal tubs with a smokestack. I think they burn fuel oil. When they light those things up across the grove, and they get fired up good, it sounds like jet engines. They shut off the air intake to turn them off. I have a friend that used to fire a couple up for his outdoor winter parties, which he'd place around the perimeter of the event, and it provided a remarkable amount of heat if the wind wasn't blowing too much. They do stink, though.
