Depends on what you are planting in them. They are fine for any heat loving plants, like zonal geraniums, Mediterranean herbs/lavender, succulents and a wide number of summer annuals. And the galvanized metal stock tanks are widely used for raised bed gardening.

Heat can make them dry out faster than plastic or ceramic containers so keep an eye on watering.

Location, location, location.

Before they can pass along extra heat, you have to be somewhere that has extra heat.

Galvanized or not, I've found they rust through eventually.

A no no depends on the size of the planter and material used. I looked up the size of those planters and they are 12" wide by 15" high by 37" long. I see Costco has them at 50% off and understand your temptation, but there will be issues you won't like, and also some simple solutions to overcome the issues.

Aluminum"s thermal conductivity is very high at 137 btu's per square foot and makes a good heat exchanger. But the exchange works both ways because heat always moves from a warmer to cooler space until they both equalize. So on cool days and nights the soil will cool just as fast as it gets hot on warm days, and not good for your plants. Most plants are sensitive to extreme changes in soil temperature and will cause roots to die and cause a lot of stress, so you don’t want it to allow soil temperature to change quickly.

These swings can also effect microorganism colonies and critical if your using organic fertilizers. High soil temperatures in the 80's is optimal growing conditions for many microorganisms including those bacteria responsible for denitrification. The high soil temperatures will result in a population explosion of organisms and any nitrogen source will quickly change into nitrates the plants can use, but will also quickly change to Nitrous oxide or nitrogen gas venting into the air causing a nitrogen deficiency even when fertilized. It will even happen with many chemical nitrogen fertilizers as well.

The size of the aluminum planter is the problem, if it was bigger, say 24" or 36" wide the temperature swings would be slower because soil has a thermal conductivity of only 0.4 to 2 and transfer of heat to and from the soil would be slower. If that size planter was Steel it would be better with an thermal conductivity averaging 25 btu per sq. ft an hour.

Looking at the planter there is an option and what I would do. Buy some 3/4" rigid foam board insulation and cut it to size to fit inside all four walls of the planter. There is room and will fit in nicely. You can glue some plastic over it, or don't because it won't matter. This foam will provide a thermal break and drastically slow heat gain and loss in the planter and prevent extreme temperature swings your plants can't handle. The thermal conductivity of wood is less than 1 and the for plastic and rigid foam board is about 0.5. If you don't want to put the foam inside the planter then don't buy them and get wood or plastic planters for that size.

" These swings can also effect microorganism colonies and critical if your using organic fertilizers."

However the lack of microbial populations and activity and the corresponding inefficiency of organics in a container regardless of material makes that issue pretty much moot.

Hey @kevin9408, thanks for taking the time to post such a detailed reply.

But the exchange works both ways because heat always moves from a warmer to cooler space until they both equalize. So on cool days and nights the soil will cool just as fast as it gets hot on warm days, and not good for your plants.

I'm not really sure this is much of an issue in my location from say June to September as I would think that temperatures do not swing much...not enough to matter.

Before they can pass along extra heat, you have to be somewhere that has extra heat.

Not really. I was simply musing, all else being equal, as to the extra heat transfer because it is aluminum vs say plastic or terra cotta or even wood.

I have used large plasterer's baths (cos sweetheart was a 'spread') many times, for permanent planters. True, they eventually rust through but I have never felt they are deleterious. for my plants. We don't really get extreme temperatures in the UK though. Healthy, long-term plantings are more contingent on the container size and planting medium (ime). Having a containerised garden has entailed a lot of experimentation, using numerous materials (from galvanised dustbins to felted fabric and everything in-between).

Galvanized or not, I've found they rust through eventually.

That's why i would only consider aluminum if I was to get a metal planter....lighter weight and it will 'never' rust.

Heat can make them dry out faster than plastic or ceramic containers so keep an eye on watering.

For sure. And if I do decide to get it I will have it be a shade container.

Isn't aluminum something that has become a concern as a toxin in the body? Coming from food? Products? Is there a possibility of it leaching into the soil and would growing food then be a concern?

I bought a metal tall planter last year and haven't put it together yet. I don't know what material it is. I am going to use it this year.

This is intended for flowers only and there are no in ground vegetable gardening on our property.

"Isn't aluminum something that has become a concern as a toxin in the body?"

kinda. To much of anything can kill you. If you ground up and turned those aluminum panels into a powder and ate them it may not be safe but the panels leaching into the soil will not hurt a thing.

I'm not going to copy and paste everything to know about Aluminum poisoning so clicking the link will educate those who seek knowledge on the topic.

"Aluminum poisoning has been reported in some parts of the world. It is one of the global health problems that affect many organs. Aluminum is widely used daily by humans and industries. Residues of aluminum compounds can be found in drinking water, food, air, medicine, deodorants, cosmetics, packaging, many appliances and equipment, buildings, transportation industries, and aerospace engineering. Exposure to high levels of aluminum compounds leads to aluminum poisoning."<<<<<<<<<<<<<<<

"The main source of oral intake of aluminum is food, which accounts for approximately 95% of the daily intake of food, and drinking water consists of 1-2%. These usually provide 4,000–9,000 micrograms intake per day [14]. Also, using antacids may increase oral intake up to 5,000,000 micrograms. Daily entry of aluminum into the body through respiration may be 4–20 micrograms. This number is increased up to 25,000 micrograms by inhalation in industrial places, and finally, exposure to deodorants containing aluminum compounds may increase entrance of this metal into the body up to 50,000–75000 micrograms per day".

"Aluminum is the third most common and ubiquitous element in the world. It is naturally found in air, soil, and water........." Click the link to learn more, or don't and continue making wrong choices in life. More than 95% of aluminum is excreted through the kidney but a wise choice in life would involve avoiding antacids and deodorants containing aluminum. Excess buildup in the bones, lungs and brain can induce a host of really nasty problems you don't want.

Now I remember the biggest concern has been cooking in aluminum pans.

Aluminum Cookware

Cooking acidic foods increases aluminum leaching into the food according to the research cited in this article. We have one large aluminum pot and the biggest use we had for it was making a large batch of Spaghetti sauce which is acidic. So we've stopped using it for that. About the only thing it gets used for now, is cooking lobsters in, which is a rarity.