Is Metal Rust Bad For Plants?

I wanted to grow some herbs in a container and found some metal ones at home. Some of them were rusting and I wanted to check if it’s a good idea to grow the plants in them.

Metal rust is not bad for plants in moderate amounts because it does not dissolve in water easily. Small amount of rust can be good for some plants as it contains iron. But you want to avoid using toxic metal containers for growing plants especially vegetables.

It’s going to be quite common to see rust on your plant containers especially when growing them outdoors. But other than giving a bad appearance, rust won’t affect your plants.

You can still avoid the rusting of the metal containers and I’ve added some information below that you may find useful.

How to Avoid Rusting on Metal Planters

Think of a car that has rust creeping along the sides of its body, an iron staircase that is slowly being eaten away by a reddish-brown intruder, or porch furniture that is nearly eaten through. None of these images are pretty sights, right?

The same can be said for metal planters that have been taken over by the beastly iron oxide. No one wants their planters to rust, but is there actually a way to keep them from doing so over time?

Untreated metal that contains iron will inevitably rust over time when it is continuously exposed to water and oxygen. This combination of water and oxygen exposure is deadly to iron because both of these components have opposite charges creating a deadly attraction. When the two are combined the iron atom loses three electrons and the oxygen atom gains two. The loss of electrons from iron forms ferric oxide, known as your everyday rust.

To combat this reaction, zinc can be put on metal to create galvanized steel. Galvanized steel containers are a great option for planting as they will keep from rusting and have a long life even when being exposed to the elements.

By galvanizing the metal, the iron within it has no problem being wet often. Just be sure that your planter has the proper drainage outlets for the plant so that it does not hold water and your plant will not be subjected to root rotting.

The Pros of Metal Planters

Affordable

When speaking specifically about planters, it is no secret that many of the products offered in this vast arena are pricey. You have dreams of creating a beautiful array of assorted colored pots exploding with different flowers and herbs that all adorn your porch leaving neighbors green with envy. However, your dreams are completely dashed when you look at a lovely blue and white planter with the prettiest of details to find out it costs as much as your car payment.

What is so great about metal planters is that they offer functionality with affordability. Metal is a relatively inexpensive material and is so diverse that it makes it easy to turn this commodity into just about anything.

By mass, iron is the most abundant element on earth and has been utilized as so ever since its value beat out bronze in the 13th century. Everywhere you look you can find metal and your planter pots are of no exception when it comes to affordability.

Plants alone are rather expensive, one small shrub tree can cost you well over 80 dollars, so being able to find a product that is useful but also cuts your wallet a break can be a very welcomed product indeed. Metal is also great in that it can be made to have dozens of different looks. If you cannot find one planter that suits your taste, keep on the hunt, there is bound to be something that fits the bill and will enhance the plants in which it keeps.

Durable

Metal’s kryptonite may be water, but other than this, it has very few vices. Metal is like the ultimate fighter champion in the material world. If you look around you, it would be nearly impossible to be in an area that is without metal.

Even in an open field, iron is right beneath your feet! Metal has a very high melting point, is strong as an ox, super durable, and can even get your lights on. You do not want to mess with this element- it will take you down.

Because of its durability, a metal pot is an exceptional choice for a planting pot. Because most pots are placed outdoors, they are subjected to fight through heatwaves, rainstorms, unceasing wind, kicks and knocks from those passing by, and the occasional pesky pet. You want something that is going to be able to withstand all of these different encounters without being easily broken or cracked. Lucky for you, metal pots can be just that for you.

Metal offers a very different advantage when it comes to durability when compared to other pots, especially those that are clay or ceramic. With strength being one of its main features it is able to withstand wear and tear much more easily than pots that are more fragile. With clay and ceramic pots, they are much more likely to crack and chip by either accidental breaks or through the simple wear of seasonal changes that can cause them to fall apart.

Easily Used in Gardening

Metal pots are great when you are looking to plant things on porches, balconies, and even windowsills, but how can metal serve you in your lovely garden spread across the personal acres of your home?

If you are new to gardening, you may be wondering “Why on Earth would I need metal in a home garden?” You have melons, different vegetables, even flowers, but don’t forget the one fruit that is always in high demand: tomatoes.

Tomatoes, instead of spreading out flat like cucumbers or squash, grow up like a vine. For tomatoes to successfully do this, they need a bit of support and this is where metal comes in for them.

A tomato cage is a supporting structure that you can find in almost any backyard garden growing tomatoes. If you were to get a cage that was galvanized, it would be able to withstand months of rain and harsh weather without getting rusted.

The Cons of Metal Planters

Heat

Metal may be the all-star of the element world, but it does have some disadvantages. After all, everyone has their faults and metal is of no exception. One of the biggest flaws of metal is its capacity to conduct heat.

If you have ever sat on a metal bench in the middle of summer, you understand this comment. You sit, the backs of your legs are almost immediately scorched off, and you wobble away seatless and fried. For plants, this can be a big drawback.

Plants require sunlight, and if you have a plant that needs an abundance of it then you will have to set your pot in an area that has maximum sun exposure. If your pot is one that is metal, the direct sun on it throughout the day can heat the soil and in turn heat the roots.

Once the roots have been heated for long amounts of time, they can dry and die. Metal also is poor for insulation and thus cannot protect your plants well from varying temperatures.

Rust

You know that rust is generally not harmful to your plants. Even though it may not be the demise of your gardening, it can certainly take its toll on the visual appearance of your potting area.

If you are using a metal pot that is not galvanized, the likelihood of rust occurring over time is high. Because of this, your once shiny pot may become one streaked with red and brown, tainting the aesthetics of your space and forcing you to purchase a replacement.

Some may not be bothered by the appearance of rust, this is a completely personal preference, but others may find its presence to be unwelcomed.

If you are wanting your pot to last long term without the worry of rust, then ungalvanized metal should be something to steer clear of. It may shine temporarily, but with time, it will fade and you will be back to square one.

Metal is Non-Porous

Water is an essential part of plants’ survival, this is no secret. Even with it being a primary source of life for your gardens, big or small, it can also be a means to your plant’s end if given too much.

Plants need to be able to drain off the water when potted in planters, but metal is non-porous which means it is not able to assist in the absorption of water if your plants get too much on any given day.

If you buy a metal container and overwater your plants, water will begin to pool at the bottom of the pot causing the roots to mold and eventually rot. To avoid this problem, be sure to purchase a pot that has drain holes in the bottom of it so that any excess water can escape through them.

If you have a metal pot that you are already using but is without drain holes, simply grab a drill and make your own drainage.