I have always been careful about what was in the barrels previously. I was always able to identify the contents. Most stuff they dust crops with is going to degrade to become harmless if they use it on food crops. Heavy metals like copper or arsenic will not, of course. Usually the proprietor with the barrels has some knowledge about what they contained, sometimes the barrels are still labeled. I have had barrels that contained ethanol, apple juice concentrate, and various oils and organic solvents. The place I get mine steam cleans them for a little extra. I usually hose them out with some soap and water for good measure. Jeff, lotuses can grow out of water pretty easily as long as the soil is just dry on the surface and not down deep, so they can be planted along the margins. Both lotuses and water lilies will grow over the sides of containers(especially shallow ones) when they become crowded. They thus become naturalized and save you the trouble of transplanting them. Should unwanted spread occur water lilies can be pretty easily controlled with glyphosate(Roundup-aquatic version) but you have to use a sticking and wetting agent as liquids just bead up on the leaves and don't distribute well. Lotuses are VERY hard to get herbicides applied to the leaves (their surface properties are so unique they are actively being researched-just read an article about that in Scientific American). Water just beads up nearly in spheres on lotus leaves. Fortunately, I have had no trouble with lotus aggression, in fact, quite the coontrary. I get stands of lotus started and they grow great and look terrific for a few years and then seemto fizzle out. Once a wild lotus strain-the yellow native lotus here- got into my pond from somewhere and took over an entire cove, growing in up to 6 feet of water. It lasted a couple of years and then just disappeared for some reason.
