I have some large ceramic containers on a brick patio exposd to the hot afternoonTexas sun. What I did that seems to help some is put some sheets of styrofoam between the pot and the soil, so at least the roots don't touch the hot ceramic surface. But it took several tries to find plants that could take all the heat. What I had the best luck with are durantas in the big pots. In some smaller pots I have some small ornamental grasses, succulents, asparagus fern. I'm still trying to find the best flowering annuals I can pop in for color. But that gives me an excuse to go to the nursery!
I had wondered if styrofoam would help but I had not thought about pot feet. I think I will do both at the same time. Thanks for your ideas and teacup, thanks for suggestions of "what" to plant that might be able to tolerate this condition. If an;yone else has had to deal with this, I appreciate any suggestions for how to do it. Unfortunately the front yard is paved with concrete. Would plastic be better than ceramic or pottery? I really like the look of terra cotta.
I would also make sure all your pots are light colored--dark pots will absorb the heat and cook the roots faster. Also consider putting the plants in a little bit larger pot than you normally would--that will give you more soil volume which will take longer to heat up, and the roots won't be all the way on the outside edge of the pot so it'll take longer for the soil right around them to warm up. Don't go too huge though unless you have great draining soil, otherwise it makes it too easy to overwater (even in TX heat)
I agree with the double potting. I forgot I did that with one really tall slender pot. I put some old plastic pots upside down(so I wouldn't have to fill it so much with potting soil) then filled it with potting soil, I found another old plastic pot to fit inside the ornamental one with about an inch of soil all around between the old pot and the ceramic one.(I think provides some insulation.)It is at the front of my house that I actually don't get out to very often and it seems to help with not having to water every single day in the summer (or under the Death Star as others have refered to the Texas sun.)So double potting works really well.Some other plants I didn't mention are ornamental peppers and pink skullcap.
I have read about something called a "Zeer Pot". You place your clay pot inside a larger clay pot, and fill the void between them with sand. Then keep the sand wet. Evaporative cooling will keep your inner pot much cooler than air temperature.
The Zeer is an interesting concept. It was invented as a refrigerator in areas where electricity is unavailable, ie, to keep food edible longer. All the discussions are very scientific with lots of engineering concepts but as far as I can tell, no one has been able to get hard numbers on the concept. People have, however, data on food spoilage in the Zeer vs food spoilage without it and the difference appears to be 5 to 10 times improvement with the Zeer. The effectiveness depends on many factors but the most important one seems to be the ambient relative humidity . The lower the humidity, the faster the evaporation and the better the cooling effect. The other thing that may be important is that the Zeer is a closed system, whereas a potted plant will not be. As far as helping some, I believe it would. To measure how much appears to have stumped smarter people than I, so far.
Thanks to all of you, I have several things I can try. I can insulate with styrofoam, I can double pot, I can use pot feet and I can double pot with sand and keep it wet, plus I can do all of the above. Thanks, all. DG'ers are are the best. Marty
During the '80's I drove concrete mixer in Houston and after I'd wash down the back of the truck, I'd hose myself down. On the trip back to the plant, running with the 255 air conditioning, I'd be nice and cooled off and my shirt was usually bone dry. After a while the other guys were doing it too, since evaporation cooling works great, and it's free. The first mixer I drove was a '79 model and this was long before air conditioning was in the mixer trucks...
I'm doing a bunch of 5 gallon bucket containers and this was one of my worries, about how to keep them cooled off. We also have a concrete patio where I plan on putting these pots...I'll probably just put some mulch underneath them and let it go at that...
It sounds like those styrofoam pots would be just the thing. Im going to start looking for them too. I'll chime back in here if I can find them. They would be like putting your plants in an ice chest. good insulation all round. Thanks, Jay. Kev, Im going to put some styrofoam peanuts in the bottom of my 5 gal buckets.
A couple of years back I bought some inexpensive styrofoam ice chests from Walmart...about $3 each. They held about 7 gals of mix. I planted two Big Boy tomatoes in each one and they did fine. The stacked containers in this photo are styrofoam and are about 9 years old and still doing OK.
I found out the styrofoam pots are actually made of polyurethane similar to the stuff you squirt into cracks to insulate and then it expands to fill the crack and hardens. The only source I found on Google is a place in China called Ali-Baba and they are wholesale, minimum order, 1000 pieces. Supposedly Ace Hardware makes a line of these but could not find them on their website. I figured I could double pot and spray that stuff in between the pots to get an insulating effect. I think the product is called "Great Stuff". I read lots of caution about painting this type pot. Most paints will melt it so research before painting if you are lucky enough to own these pots. They were so scarce, I wondered if they are banned here or something. If anyone finds a domestic source, please post here. I would want large sizes 16, 18 inches diam.