Finding the perfect gardening solution is a constant struggle that you will be facing when you first want to add some zest to your place. The first thing many vegetable gardeners think to use are various PVC products. Why? Simply because this material is extremely easy to get. You can comfortably shape it into anything, and it will cost you very little. Although PVC is often in abundance, we must question whether it is safe to grow vegetables in such a material?
It is not safe to grow your vegetables in PVC piping; there are chemicals in PVC pipes that leach into the soil, usually phthalates from PVC, which gives PVC its flexibility. The plants soak the toxic chemicals, which it then transfers into any vegetables. (Source: The Micro Gardener)
You will need to understand precisely why PVC is toxic, why the pipes are toxic, and how hard it can be to build the material in an eco friendly way. Many people have learned the hard way that PVC is not always the miracle material; we have worked through much research to determine why this is. The dangers of using plastics like PVC and the challenges of doing so correctly should never be underestimated.
Are PVC Pipes Toxic?
Yes, regular PVC pipes are highly toxic to you, your plants, and the overall environment. The material is found in almost every product in the modern world; while it is perfectly fine to use in toys, cars, piping, and everything else when new, the plastic does deteriorate. Added chemicals in the production of PVC eventually leach out of it, with the actual pipe finally cracking and breaking up into microplastics. (Source: Eco Watch)
Beyond the PVC pipes themselves, the entire production process for the pipes is highly harmful to the planet and the ecosystem. The problem with PVC pipes is that it is the most commonly used plastic pipe globally, which is why many people are attempting to upcycle them. However, as you learn more and more about the product, it becomes clear that it should not have been made at all.
PVC pipes are considered a good option for their main use case, which are for long underground pipe lines that usually have lower pressure systems. However, all PVC pipes eventually degrade, leaching their chemicals into the ground around them. This is usually when you see PVC pipes with long cracks in them and a rough exterior surface. If no alternative can be found, we recommend that you still don’t use the pipes, especially if you need to buy new ones.
Why Is It Unsafe To Grow Vegetables In Normal PVC Pipes?
Polyvinyl Chloride is a type of plastic that naturally is quite brittle and sensitive to changes. To overcome this, the chemical phthalate and others are added. This gives the pipes and other products their characteristic flexibility; however, these same chemicals eventually leak out and into the soil the plants grow in.
It is unsafe to use PVC piping for vegetable gardens because any dangerous chemicals that a vegetable plant soaks up will be pushed over to its vegetables. Whoever eats vegetables planted near aging PVC piping will high a high chance of ingesting these chemicals too. This leads to diseases, asthma, in some cases autism, and a long list of health problems that can be hard to wrap our head around! (Source: The Micro Gardener)
It does look tempting on paper to get rid of all the waste PVC pipes littering the world by using them to grow more vegetable gardens. However, these plastics are not meant, designed, or safe for growing food. Your plants might thrive, flowers may even grow in them, but nothing produced by the plants will be edible by humans, animals, or bugs.
What Can You Use PVC For In Your Garden?
Now that you know that you should not use PVC for any plants or pots, you may be wondering what you can use the PVC for. Several things around the garden can benefit from the strength and structure that PVC provides. However, we would like to point out that a PVC irrigation system has the same faults as a PVC potting garden.
We have seen many people successfully using PVC for building structures that help make the garden look a lot more organized. Even if it is just as a structure on which to create something more grand and complex, in these cases PVC pipes can be used to improve the look of the garden. We would like to add that if it is possible, you should still be using safer materials or just using uPVC, which is PVC piping without any added chemicals but does offer a lot less structural stability.
Using PVC For Protective Structures
Mini greenhouses, tents for your children to play in, a way to add some shade or a wall structure from which to hang your proper vertical garden. These structures will need a skeleton to work on, and PVC pipes can provide this if adequately connected. We have seen several facilities worldwide that have been built using nothing but PVC pipes and fine wire mesh.
As the PVC ages from the rain and sunlight, you will replace it with newer pipes that can keep their same rigidity. So it is fine to use those PVC pipes for fun structural or cosmetic projects in your garden, just remember to ensure that no food, water, or soil comes into close contact with the piping.
Using PVC for Underground Irrigation
PVC pipes are made to be deep underground, where they transport and protect sensitive materials from outside weathering. This is why you will see people using PVC pipes several feet underground to transport waste, to protect cables, or as a runoff for storm water. Using PVC pipes in this manner in your garden will be a great benefit to it overall.
If you have a raised vegetable garden and you need to make sure that water does not get trapped in it, you can place the piping at the very bottom, covered with a layer of rocks. Then simply drill through the top of the pipes and connecting to a wastewater area. This will keep the pipe dry most of the time, away from your soil, and have it get rid of excess water with absolute ease. So chemical leeching won’t be an issue.
What Should You Not Do With PVC?
The problem with PVC piping is it is a common site for most gardeners but most of them are totally unaware of its hidden dangers. There are many things that PVC was never meant to do, most of which people have mistakenly assumed the material would be fine for. This is why we now have so many reports of people getting sick for mysterious reasons after they have made their gardens.
PVC is not a miracle material; people need to be aware of its chemical composition and treat it accordingly. In the same way, most old school gardeners won’t use treated wood to plant a garden; for similar reasons you cannot use PVC and plastics to create a garden. Every time you use PVC for something that it cannot and should not be used for, you risk endangering the health of yourself and those you hold dear.
Using It For Above Ground Watering
This is possibly what you will see PVC pipes used most often, with irrigation systems to either spray or slow drip over a vertical vegetable garden. While this is undoubtedly an effective way of watering everything, it is also an effective way to turn the soil completely toxic. PVC pipes suspended above a vegetable garden are usually subject to a lot of heat from the sun and will degrade faster than you could control.
While it may be tempting to build such a system, it will not be effective in the long run; you would have to dispose of all the plants growing in this condition. Building an above-ground sprinkler or irrigation system with the right plastics is not any more expensive. Several plastics are not only rated for constant sun exposure but will allow you to have a great deal more control over the pressure of the water you are spraying.
Don’t Use It For Planters
We have said this before, but we must repeat it, PVC cannot be used as planter material for your vegetable garden as the plastic leaks toxic chemicals into your soil. As the plants grow, they soak up the toxic chemicals and transfer them into the vegetables you are hoping to eat. In addition, depending on the plants and the compost you are using, the plastic will break down faster thanks to the acid levels in the soil.
PVC does not last long when exposed to water, moisture, heat, and different soil types, making it a temporary solution that will degrade in only a few years. There are multiple other materials, including wood and clay, that can create planters for your vegetable garden. Each one is better and longer-lasting than PVC could ever be.
Be Careful What You Glue It With
If you are using PVC, we recommend that you at least ensure that you are using food-safe glue, as this is something many make a mistake with. For example, PVC pipe glue that you might use for your swimming pool pipes will not be healthy or safe to use with your water irrigation system. These glues usually have a high toxicity rating, with some of the strongest glues melting the plastic together.
Having any of these glues near your vegetable garden will not offer you any benefits and will usually cause you to be highly sick once you consume the vegetables. There are glues on the market that are non-toxic that will work for the irrigation system you are using. However, you will notice that most, if not all, proper gardening irrigation systems do not use glue. Instead, they rely on pressure fitting to ensure everything work without dangerous toxins.
Consider Food Safe PVC as a Replacement!
Food-safe PVC is also called Unplasticized Polyvinyl Chloride, and a few companies worldwide only make it. This PVC is also called uPVC and has none of the dangerous BPA or Phthalates that make regular PVC dangerous. However, this also means that uPVC is extremely rigid, is inflexible, and can still only be used to transport drinking water. The most important part about uPVC is that it is entirely recyclable as the chemicals are usually why PVC cannot be remelted. (Source: New England Arbors)
When people usually want food-safe plastics, they will use entirely different vinyl, HDPE, or PETE plastics. These are all things that do not have high chemical content within them and will not leach these toxic chemicals into whatever they contain. We have seen many people use these for their gardens in some of the most creative ways imaginable. As these plastics offer no danger, you can plant things in them and leave them for nature to eventually reclaim in a few hundred years.
The plastic used for piping and irrigation, the black bendable pipes you may remember, is called either Poly Tube or PEX piping. Both are meant for underground use and can be connected without using any glue. These piping types are used so often because of their extreme flexibility and that they do not degrade and leach toxic chemicals into the plants they are watering.
While it seems like a good idea on paper, and it certainly is a good idea for up-cycling, regular PVC pipes are not meant for planting vegetable gardens. They will leak chemicals into the soil that the plants eventually soak up, which causes dangerous and debilitating diseases. While food-safe uPVC might not have this problem, the material will degrade quickly, becoming unusable and crumbling at your fingertips.
We recommend that you use materials made for potting; untreated wood will always be the vegetable garden champion!