Yellawood is supposedly certified as safe for most any gardening use - comes up for discussion often for use in raised beds. The only things it leaches is copper.

CCA treated wood (the green stuff with arsenic) has been banned from sale since federal law in 2002 except for commercial construction.

No personal experience with using it as tomato stakes but that's just because I don't like staking tomato plants, not because of the wood.

Dave

I use cedar, It is a bit more expensive though.

I would make a hohe with a rebar ,or somethind, then I drive the sharpened end into ground. I buy like 1 by 4"s and rip it on table saw. This way it is quite less costly than if you want to buy the ones sold by piece at like 3 bucks each. Rebaris another alternative if you want something that lasts for the rest of your life and beyond..LOL