Call your local independent garden center and inquire as they may offer bulk delivery or know who does near you, unless you only need a little and a few bags will do. Where I garden there is a large organic farm that sells both bulk and bagged in the region, McEnroe, and I see that they have a where to buy page with a map — but maybe just call them. Some friends like Coast of Maine products, that a lot of garden centers carry. Both of those are certified organic producers, which is my preference if/when I need bagged stuff.

Hi, Geno. Usually ants are not looking to eat a plant, as much as being attracted by something else, I believe — for instance, by the sticky secretion made by aphids, called honeydew. I do know that aphids can be parasitized by wasps (like this) but as for ants on the roots of a tomato specifically, and so on, I don’t think it’s about the tomato specifically. I would be inclined to use water to try to dislodge/discourage them and also check the plant carefully for signs of aphid infestation or honeydew.