Reverse of each packet includes the heading "Easy to Grow Wildflowers", and the following copy: "This packet contains a mixture of favorite annual wildflowers, including red poppies, annual baby's breath, cornflowers and others. These flowers are annuals - they'll sprout and only bloom in the first year, although some will reseed. For perennials or to learn more about wildflowers, as well as flower bulbs, perennial plants and more, visit us at AmericanMeadows.com." Postcard size is 6 1/2" wide x 4" tall. When mailing, please contact your local USPS to determine the exact postage rates.