Is Pressure Treated Wood Safe for Vegetable Gardens?

For numerous many years, frequent expertise held that substances utilized in pressure taken care of wood can leak into the soil creating the vegetation toxic. Inititally, the chemical compounds utilised to handle wood such as creosote, and pentachlorophenol, ended up a little bit toxic and would pose a well being hazard to the crops and soil.

Even so, due to elevated study, restrictions ended up set in place and better and safer means of managing wooden have been designed.

At present, force dealt with wooden authorized for use in residential areas is safe for human beings, soil and vegetation. It makes use of modern day signifies of preservation such as such chemical compounds as alkaline copper quaternary,copper azole, naphethanate and HDO.

In this report, we will get an in depth seem at no matter whether strain handled wood is protected for your elevated vegetable garden, and the results it may possibly have on the soil and crops.

Earlier Methods of Preservation

Pentachlorophenol, creosote and chromate copper arsenate ended up all first used in the 1930s but had been all later on located to be hazardous soon after in-depth study as seen under.

Is Pressure Treated Wood Safe for Vegetable Gardens?
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The chemical was 1st produced n the thirties and was later registered as a pesticide, and an oil-based preservative by the fifties.

Nonetheless, it was later on understood that Penta experienced adverse consequences on vegetation and individuals alike, creating pores and skin irritation and plat death. It is at the moment labeled as a limited pesticide not excellent for treating wood or other inside utilizes.


Creosote was a combination of about 400 various compounds which had been blended to create a merchandise effective towards fungi, insects and maritime borers. However, on the downside, the items were found to be carcinogenic with adverse results on each crops and individuals.

At the moment, creosote is allowed to be utilized for railroad cross ties, marine buildings and this sort of, but is restricted in managing wood that will be linked with foods feed or consuming drinking water.

Chromated Copper Arsenate (CCA)

This was originally designed as a wood treatment substance for use in the US up to all around the 2000s. Even so, elevating issues about the chance of chromium leaching out to the soil led to the require for in-depth research.

The finding was that CCA must not be employed with residential projects these kinds of as household furniture, decks, playground buildings and lifted backyard beds. This was because of to the proof that rainfall and solar radiation aided release arsenic from the wood, which was far more widespread in the situation of acidic soils. CCA was cancelled on December 31, 2003, for all household use.

Is Pressure Treated Wood Safe for Vegetable Gardens?
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Modern Wood Preservatives

In the wake of the new info supplied about the older components utilized in wooden preservation, newer safer strategies of wooden preservation had been sorted right after and the outcome was Alkaline Copper Quaternary (ACQ), Copper Azole (CA), Copper (HDO) and Copper naphthenate.

Let’s consider a search at every single one of these:

Alkaline Copper Quaternary (ACQ)

ACQ has been all around given that the 90s but only improved in recognition right after the removing of CCA from the market place. It is currently 1 of the most employed goods in force taken care of wood and acts as equally a fungicide and an insecticide.

The product will come in multiple versions which include ACQ B, C and D, all with minimal variations of the compounds and formulas utilised to make them. ACQ has been registered for use on merchandise such as wood structures, wood shingles, sea walls decking, marine pilings, fences, posts, raise beds and many much more.

Research carried out indicates that ACQ dealt with wooden is non-toxic to both oral and dermal publicity thanks to the copper oxide and quaternary ammonium items employed in pressure treatment.

Copper Azole (CA)

This is yet another well-known product for stress-taken care of wooden, specially in the U.S and Canada. It is a drinking water-based wooden preservative that helps prevent fungal decay and insect attack. The product will come in two variants with kind A consisting of tebuconazole, boric acid and copper even though kind B has only copper and tebuconazole.

It is registered for the therapy of previously mentioned-floor, salt drinking water and fresh drinking water decking purposes. It is also authorized for use in shingles, shakes, structural lumber utility poles, plywood fences and more.

Is Pressure Treated Wood Safe for Vegetable Gardens?
Southern White Ash Wood (Image Credit: Stephen Ondich, Wikimedia Commons, CC BY-SA 4.0)

Copper HDO

This is yet another solution registered in 2005 that guarantees no contamination to the soil vegetation or h2o, as the resources are not probably to leach out. It is great for your lifted vegetable beds as it is advisable for use on treated wooden. However, the material is hugely harmful to aquatic organisms and is not allowed for use in aquatic places.

Copper Naphthenate

Copper naphthenate has been there for a whilst, largely employed as a Penta substitute merchandise. It is effective in opposition to bugs and fungi and will aid shield your raised vegetable backyard garden.

It is favorable for force-taken care of wood, which can be utilised for each floor speak to and lifted beds poles docks and fences.

Why Has Copper Become More Popular for Pressure Treated Wood?

Of all the products which have grown in acceptance over time, copper has turn out to be an vital component and the issue might be why? For 1, copper is strongly suitable with soil and binds soils at a neutral pH of 6-seven. This translates to copper becoming almost harmless to the plant and will continue to be in the soil.

Just include in a bit of experienced compost to preserve your crops pleased and healthful.

Is Pressure Treated Wood Safe for Vegetable Gardens?
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Tips for Using Pressure Treated Wood in the Garden

Having observed the developments in excess of time into a safer type of dealt with wooden, there are a couple of tips that might come in helpful whilst working with pressure-taken care of wooden. Some of these incorporate:

Is Pressure Treated Wood Safe for Vegetable Gardens?
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How Will You Know If The Wood You Bought Is Actually Pressure Treated?

You may possibly not be aware of what strain handled wood will search, feel or scent like, which might depart you vulnerable to unscrupulous dealers.

Right here are some ideas you can use to decide the wooden is stress handled.

Smell Test

If you have no way of telling if the wooden is strain dealt with, then scent it. If it is dealt with it will come with an oily or chemical scent. Even so, if the wood is not taken care of it will appear with a sweet scent of natural wood

Check The Color

One more clue you can check for to ensure the wooden is stress dealt with is the coloration of the wooden. In circumstance the wood is previous or weathered such that it only appears grey, cut it and observe the interior.

In case you come across an olive green tint on the wood, it is a wonderful indicator that the wooden has been force taken care of.

The Stamp

Verify the wooden for a stamp indicated “L P22,” it implies the wood has been handled with arsenic, which is not as protected and is only great for this sort of items as fence posts. If the stamp is composed “L P2” it is not as poisonous. For the most secure sort of taken care of wooden go for the 1 with the stamp prepared “FDN,”

There are specified woods treated with borate that are risk-free for residential use and risk-free for human beings. They appear with a stamp composed “Bor,” “Hi Bor,” or “TIM Bor.”

Is Pressure Treated Wood Safe for Vegetable Gardens?
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The End Tag

This is the least difficult strategy of determining handled wood as it will occur with a tag that will provide all the information on the type of therapy the wood has gone through.

Connected Read: Is Galvanized Metal Risk-free for Vegetable Gardens? What You Want To Know!

Frequently Asked Questions

How long does pressure-treated wood last?

Based on a variety of elements, the shelf lifestyle for your handled wooden will be everywhere between 10-20years. This will rely on longevity, budget, weather, and availability.

Is Pressure Treated Wood Safe for Vegetable Gardens?
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What is the best wood for a planter box?

There are a pair of woods best for a planter box such as cedar, oak and redwood, which are resistant to bugs and termites. They are also sturdy in the aspects but are a bit a lot more costly.


Formerly the use of harmful chemical compounds on strain-dealt with wood may possibly have been the explanation for most of the distrust of force-treated wooden we see these days. Nevertheless, more than time, this has transformed and safer possibilities have been set in place. Stress treated wood is now deemed secure, and will arrive with additional advantages that will aid defend your vegetation, and return your expenditure in phrases of extended term services.

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