He stated in a bulletin titled treated wood in raised bed gardening scientific evidence and data have shown that using pressure treated wood for raised bed or box gardening is safe to adults and children in terms of the plants grown and used in these containers he further explains all chemicals in consumer products have a toxicity and most are very low so they are not a problem especially those regulated by the federal government.
Pressure treated wood for garden beds.
Redwood has been known to last for up to 20 years.
Treated lumber many new gardeners and even experienced ones turn to treated lumber when sourcing materials for raised beds due to its added protection against moisture and the associated rot and bug damage.
Pressure treated lumber is used for fence posts garden beds decking playground equipment and many other structures that are either partially below ground or have significant exposure to the elements.
However while treated lumber will hold up better over time it can also leach harmful chemicals into your soil.
What is treated lumber.
From what i ve seen the consensus is that the chemicals do leach out of the wood into the soil and are uptaken by the plants in very small amounts.
Yes the new pressure treated wood is safe for use for raised garden frames.
This is where the problems began.
Romaine lettuce grown in pots with soil in which small amounts of compounds such as arsenic were also tested to see how much of the chemical would be absorbed by the plant.
Why would it not be safe.
You can isolate pressure treated wood by lining the inside of a bed with heavy plastic to prevent leaching of chemicals from the wood into the soil.
Many organic gardeners use this combination and feel fully comfortable with the result.
Alternatively you could build the frame of your vegetable garden with pressure treated wood acq or cba then cover the inner wall with a sheet of plastic so that no copper from the wood ever touches the soil it contains.
Top your bed with boards of untreated lumber to make a flat top to sit on and to avoid contact with the wood particularly if you have cca treated wood in your garden.
Best wood to make raised garden beds redwood expensive but long lasting redwood raised garden bed.
The concern is that the chemicals that are used to treat the lumber can leach into the soil.
Arsenic copper and chromium levels found in the vegetables grown in raised beds made from pressure treated wood were the same as conventionally grown vegetables purchased from a grocery store.
Amazon this wood makes perfect raised garden beds.
The main reason is that redwood is naturally rot resistant.
Regular lumber begins to break down within the first year if it comes in contact with the soil so many gardeners used to use pressure treated wood for gardening such as landscape timbers and railroad ties which is chemically treated to withstand the weather.
Hence you can use redwood without having to treat it or apply any finish.