Holiday Recycling Tips & Why Some Items Can’t Go In: Portland allows us to recycle a lot of things curbside, including plastic plant nursery pots, empty spray oil cans, motor oil (next to bins in a clear milk jug) and food waste. (In fact, in 5 years of curbside composting, we’ve been able to turn food waste into over 400,000 tons of finished compost, which is enough compost to cover 2,400 acres of farmland, (about 4 square miles). That alone is a lot of volume kept out of our landfills!