Is Pressure Treated Wood Safe for Vegetable Gardens?

Is pressure treated wood safe for vegetable gardens like in this image

People love growing herbs, vegetables, fruits, and other plants in boxes made from pressure treated wood but is pressure treated wood safe for vegetable gardens? These garden boxes have soil filled in them; they are then strategically placed on lawns, balconies, patios, and open porches with adequate exposure to sunlight. We need to answer this question:

Yes, the “modern” pressure treated wood is safe. You can use it to construct raised garden frames. Before 2003, a dangerous chemical, chromated copper arsenate (CCA), was used to treat wood. However, the U.S. The Environmental Protection Agency (EPA) abolished its usage for being “a human carcinogen.” Safer chemicals Alkaline Copper Quaternary (ACQ) or Copper Azole (CA-B) have since been approved for the pressure treatment of wood.

A lot of people have reservations about whether it is safe to use pressure treated wood in the garden. It’s because of the fear that the chemicals present in the treated wood could leach into the soil and possibly be absorbed by the plants.

The “old pressure treated wood” posed risks of arsenic getting into the soil. Well, arsenic is indeed dangerous, and nobody can argue against that. However, arsenic has not been put to use when treating residential lumber in more than a decade. From the year 2004, the Environmental Protection Agency(EPA) ended the use of arsenic in a residential application. Today, wood treatment involves the use of copper to prevent decay.  

The human body needs copper mineral and is by far much less dangerous compared to arsenic. 

Why Use of Copper In Pressure Treated Wood Is a Good Choice 

Copper is an element that strongly compatible with soil; it binds mainly to soils with a neutral pH of 6 – 7 and very fertile lands. It implies that the copper will only stay in the soil, which reduces every chance of its absorption by the plants.

The presence of copper in the soil should, therefore, not give you sleepless nights. All you need is to keep the fertility of your soil up through a constant addition of compost. This practice will make your crops grow “happily” and, at the same timekeeping copper absorption to a minimum level.

Tips For Healthy Vegetables In Pressure Treated Wood Beds

Are you a garden owner and only interested in growing purely organic veggies and fruits? Well, we have steps that you can follow to ensure your plants have the least possible exposure to the pressure treated wood:

  • Have your crops planted at least a foot away from the walls of your pressure treated wood. It’s highly unlikely that the preservatives will leach into the soil beyond this distance.
  • Consider lining your raised beds using plastic sheeting- a move that will create a leak-proof barrier between the roots of your plants the pressure treated wood at the edges of your bed.
  • Peel all the root crops before eating. Naturally, the roots tend to absorb more copper than the other parts of the plant; these elements are in plenty around the peel. Therefore, peeling will help you remove most traces of copper.

Note: Most of the modern pressure treated woods are safer choices for making the edges of your home vegetable garden. 

Best Alternatives To Pressure Treated Wood for Home Vegetable Garden

  • One of the very best choices for your vegetable garden frames is local cedar. It doesn’t require any chemical treatments or sealants thanks to its natural oil components, which makes it resistant to rot.
  • Consider the use of reclaimed redwood, which usually is available at specific construction material reuse centers. After the acquisition, seal the wood with linseed oil by yourself.
  • Another viable option for your vegetable garden frame is recycled plastic. The plastics are incredibly durable and corrosion-proof; this is a quality that makes a perfect garden framing material.
  • Generally, the use of all-natural finishing oil, plant, and mineral-based lumber treatments are healthier and weather-proofing alternatives compared to chemicals like arsenic.
  • There are sealants such as Deck Boss, LifeTime Wood Treatment, and SoyGuard Premium Water Repellant. These sealants are more natural, non-toxic, yet very useful when it comes to offering protection to your vegetable garden.

Tips When Using Pressure Treated Wood in the Garden

  • Some types of pressure treated wood are not for home-usage. Cross-check the label attached to the wood to ensure that the kind of wood you are buying is acceptable for your project.
  • It would be an excellent move to use wood that is naturally resistant to rot. More options are the likes of bricks, synthetic lumber, concrete blocks for construction projects.
  • Have your protective gloves on while dealing with unsealed pressure treated wood to minimize the chances of exposure to your skin.
  • Ensure that you are wearing a dust mask whenever cutting pressure treated wood to avoid inhaling treated sawdust. Specks of dust coming from untreated wood can irritate you as well, so this precaution applies to both cases.
  • Avoid burning pressure treated wood at all costs. There are toxic chemicals used in the treatment process that can come out to the atmosphere alongside the smoke.
  • Seal the wood using a specialized paint or sealant. The use of this barrier ensures that the chemicals do not leach into the soil.
  • Sealants can further reduce the number of residues that remain on the skin when touched by kids or grown-ups.
  • Always wash off dirt from vegetables grown in garden beds with pressure treated wood. It’s because sometimes the soil holds higher levels of wood preservatives compared to the plants themselves.
  • If you grow edible plants in your garden, then have them planted away from the edges of pressure treated wood. Soils right next to these treated wood are very likely to be with higher amounts of chemicals.

How To Determine If Wood Is Pressure Treated

There are a few things that you can look into the wood to determine whether or not it is pressure treated. They include:

  • The End Tag

Usually, pressure treated wood comes with a label in the form of a stamp designated as “ pressure-treated wood.” In most cases, you will find that the chemical used in the pressure treatment is stamped there plus the rating, preservation company, and many more.

Even as you check for end tags on your pressure treated wood, ensure that you avoid all the wood that has been treated using Chromated Copper Arsenate (CCA). This wood preservative has a form of arsenic that increases the risk of contracting cancer; hence it is prohibited from any use on the decks, playgrounds, and other outdoor-home settings.

  • The Stamp

Image of pressure treated wood but Is Pressure Treated Wood Safe for Vegetable Gardens?There is still the usage of CCA-treated wood in the construction industry, especially for structural support. In case the wood you are using underwent treatment after 2003, then it is very likely that it has alkaline copper quaternary (ACQ), which is safe for home usages.

Check your wood and see if there is a stamp with the indication “L P22,” which means that there is arsenic use in treatment, which is the least safe chemical. This wood type can withstand direct contact with the earth, especially if you decide to use it for fence posts. Wood with a stamp “L P2” is not as toxic, and therefore you should avoid using it for the construction of structures such as playsets.

If you come across a pressure treated wood with an indication “FDN” on the stamp, consider it for use as it is one of the safest. 

Additionally, there are woods treated using borate, such woods are safe for home usage in both internal and external environments, and they pose no risk to humans. You can identify them by stamps such as “Bor,” “Hi Bor,” or “Tim Bor.”

  • Check The Color of The Wood

Sometimes, these woods do not have end tags or stamps, so how do you go about such a situation? 

You’ll need to check for clues, such as the coloration of the wood. If you notice a faint olive-green on your wood, it means it is treated. In case your wood is old and weathered such that you can only see gray, then cut a piece of the wood and observe the color on the inner side of the wood.

Additionally, you can choose to check in the grooves or joints; if you see a green tint, there’s CCA in the pressure treatment.

A borate-treated wood has a blue color.

  • Carry Out a Smell Test

In case there is no distinctive clue in trying to see if the wood is pressure treated or not, you might choose to use the most basic sense, which is smelling. Take a piece of wood and sniff it deeply. If it is not treated, it will have a sweet smell of natural wood. Most pressure treated wood comes with an oily or chemical smell.

NOTE: What makes CCA treated wood very dangerous and harmful to health is that it does not have a distinct smell, so you might not even realize that the wood is treated.


Until two decades ago, pressure treatment of wood involved the use of a poisonous chemical so it was always going to concern many owners of structures created using pressure treated wood. Today a lot has changed and the chemicals that was once considered harmful, chromated copper arsenate (CCA), is no longer in active use. So

Is Pressure Treated Wood Safe for Vegetable Gardens?

Yes, the current pressure treatment of wood involves the use of less toxic chemicals therefore you can use it to make vegetable garden frames; there are, however, a few necessary precautionary measures. In the article, we have discussed all the required approaches for you to have your crops thriving in your vegetable garden with pressure treated wood as the frames. Stick to the above guide, and there will be nothing to worry you.

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Tyron Otieno

Tyron is an avid woodworker and writer. He founded this website to help other woodworkers, whether hobbyists or professionals by sharing his knowledge and experiencie after a decade of woodworking.

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