Last week I did some cemetery flower arrangements for you and I used floral foam in the plastic containers. I meant to tell you that you DO NOT HAVE TO USE FLORAL FOAM in those containers. I like to use it because it keeps the flowers where I want them to be. But, those plastic containers hold quite a bit of water, and the style that I used is generous in size so you could easily place a store bought bouquet of flowers right into one of those containers. Flower will last longer in a vase of water than they will in floral foam too! I’d also suggest using flowers that are longer lasting like carnations, mums, alstromeria, orchids vs. roses, delphinium, dahlia, tulips, gardenias and hydrangea which would not hold up that well in an outside, uncontroled temperature.