Vegetable bed with treated pine timber

[jalam]

Hi guys, I built a raised vegetable bed 400mm high and 4.0m length and 1.2m with treated pine timber H4 (CCA). I will plant a avocado tree and some vegetables.

I didn't know the CCA treated pine (https://www.bunnings.com.au/200-x-50mm-2-4m-h4-ironwood-classic-treated-pine-sleeper_p8500076) is suitable for vegetable bed as it has arsenic. What's my option to fix it?

- Replace it with other timber suitable for vegetable garden like Sienna Treated Pine (https://www.bunnings.com.au/ironwood-200-x-50mm-2-4m-sienna-treated-pine-sleeper_p8423133)?
- Line inside of the bed with builders plastic? Is it gonna be durable and safe for long term?

[AJ.]

Hi guys, I built a raised vegetable bed 400mm high and 4.0m length and 1.2m with treated pine timber H4 (CCA). I will plant a avocado tree and some vegetables.

I didn't know the CCA treated pine (https://www.bunnings.com.au/200-x-50mm-2-4m-h4-ironwood-classic-treated-pine-sleeper_p8500076) is suitable for vegetable bed as it has arsenic. What's my option to fix it?

- Replace it with other timber suitable for vegetable garden like Sienna Treated Pine (https://www.bunnings.com.au/ironwood-200-x-50mm-2-4m-sienna-treated-pine-sleeper_p8423133)?
- Line inside of the bed with builders plastic? Is it gonna be durable and safe for long term?

In another lifetime I managed a CCA timber treatment plant. Your sleepers will be safe, there is no need to be concerned about the arsenic at all. Arsenic has a very short half life and the amount that would need to leach out and be consumed in a short period is so great that it is beyond impossible. The Chrome is far more dangerous than the arsenic, but still not even remotely a concern.

Cheers Andrew

[rod1949]

Why would you want to plant an avocado tree in a veggie patch? In the short term while the tree is a young seeding it would be okay but eventually the tree is going to be 4-5 metres tall and cast a lot of shade, veggies don't like shade, and then there will be the tree's root system which will be a nightmare to dig around.

Up until about a year ago I had raised treated pine veggie beds for about ten years. I'm still alive and kicking. It was the weeds that beat me.

[jalam]

Hi rod1949, I have clay soil in the garden and avocado doesn't like clay soil, that's why built the raised bed to plant the avocado in one side and veggie on other side. I will keep the avocado compact, it's semi dwarf lamb hass so won't grow that big.

[FenceFurniture]

In another lifetime I managed a CCA timber treatment plant. Your sleepers will be safe, there is no need to be concerned about the arsenic at all. Arsenic has a very short half life and the amount that would need to leach out and be consumed in a short period is so great that it is beyond impossible. The Chrome is far more dangerous than the arsenic, but still not even remotely a concern.

Cheers AndrewAgreed. 4-5 years ago I had the same concerns and did quite extensive research. The amount of arsenic that leaches into the soil is very small, and the amount of that small amount that is taken up by plants without 25cm is infinitesimal. Unlikely to plant anything close than 25cm to the timber anyway, so all is well.