These should be carefully gathered, as they are excellent to mix with hot-bed material. They do not heat so rapidly as stable-manure, and in this have an advantage, as tempering the violence makes manure last longer and maintain a more regular heat. They are excellent material to put round cold frames to protect half-hardy plants. A board is put up to the height of the frame boards, and about a foot or more from them, and the leaves filled in between. If the plants are somewhat tender, the bottom of the frames may be filled in a few feet with the leaves. Fallen leaves, after having been two or three years decaying, make admirable stuff for potting plants and for flowers in general.