Even plastics designed to hold food items leech stuff. I read a report about Nalgene water bottles leeching stuff even though they are regarded as one of the best plastics to use for water bottles. The question isn't 'will it leech stuff', the question is what will it leech and should I be concerned. Actually storing a food item in a container is another subject. Here we are talking about using plastic containers to grow edible plants in. To be worth worrying about the substance leeched would have to be taken up into the plant and we would have to consume enough of the substance for their to be a toxic affect whether immediately or long term from accumulation. This really isn't something I worry about. Many types of containers sold for the purpose of growing plants leech something. Cleaning a container previously used to hold something toxic, like paint, is a good idea, but beyond that I doubt there is any true health concern in using 5 gallon buckets made out of the same plastics as food containers are. If it has a number 1-7 in the recycling triangle it is a plastic used for food storage (and other purposes). This is my opinion.

That's what I use them for too. And for storing dry fertilizers (I really need the lids too, but I manage to get by with heavy plastic). I agree, they might be too narrow for bareroots (expecially the ones I received this year). Might be OK for own roots for a short time, though.

Food grade buckets are easy to come by. All sorts of restaurants, bakeries, coffee shops, and delicatessens will give you free used buckets that were used for storing edibles (olives, pickles, coffee, frosting, etc.), and most will even save them for you if you ask. Your buckets probably are safe, but why risk it when you can get other ones for free that are 100% safe? If you want to recycle the buckets, most recycling centers that take plastic will accept 5 gallon buckets if they are #2 plastic.

If you put a cup full of water in a cooler (insulation) and put it in the freezer next to a cup that isn't insulated, what does the insulation do? Does it keep the water in the cup warmer? No, it helps to reduce the rate at which the cup loses heat, but ultimately both cups of water will be 0* if your freezer is set at the same temp mine is set at. HOW you insulate makes a big difference. If you set a plant in a cardboard box outdoors, the temp in the box will lag the drop in temperature of the air surrounding the box, but it will eventually equalize with the exterior temperature .......................... if it wasn't for the geo heat rising from the earth. THAT will keep what's IN the box warmer than the surrounding air. But wait - you have a layer of cardboard (insulation) under the box, blocking the upward rise of heat - what about that? That layer of cardboard is actually counterproductive. Better, that you use a box with the bottom removed to cover the plant. Where I'm heading is, the insulation must be used as a method of trapping heat from an extraneous source, or it's ineffective. In your case, wrapping the sides of the container + the top in bubble wrap and leaving the bottom uninsulated, then setting the pot directly on the ground will trap geo heat & keep roots warmer. Your Celest should be hardy in a pot where you are with no special treatment, if it's setting on the ground. I don't know about the passion fruit. On extremely cold days, bringing it into a garage would significantly moderate the lows it would be exposed to - maybe even the cover of a car port would be enough. Al