Memorial Day is a patriotic holiday and the flowers that are most often used reflect patriotic colors of red, white and blue. Some red flowers available include geraniums, roses, lilies, cosmos, poppies and tulips. White flowers include daisies, peonies, dogwood, geraniums, lilacs and roses. Choices of blue flowers are iris, delphiniums, cornflowers and delphiniums. You can also make your arrangement using a single color of flowers and add a florist's bow made with the other two colors.
A beautiful memorial is a wreath. They are easy to craft with artificial silk flowers and can be made in a number of different styles. Start with a commercial wreath form that is made of straw or grapevines. Choose three different kinds of flowers and some greens. Cut the stems off your flowers and hot glue them to your wreath form. You can cover the entire front surface in a pleasing design or cluster a few flowers in a section of the form. Fill the spaces between the flowers with green leaves. You can add miniature flags, stars or a florist's bow with streamers. Display the wreath on a simple wire easel beside the head stone.
Silk flowers can be arranged as a hand-tied bouquet, as a potted plant or in a more elaborate urn. For a bouquet, choose flowers that are three or four different sizes. Hold the stems in your hand while adding the flowers to your bouquet. When you are pleased with the design, secure the stems with rubber bands. Spiral satin ribbon around the stems and secure the ends with a dot of hot glue. To make a potted plant or an urn, glue plastic florist's foam in the bottom of a weatherproof container. Hot glue the ends of the flower stems onto the foam. Place sheet moss to the top of the planter hot glue it in place to hide the foam.
Check with your local cemetery about its restrictions. Some cemeteries provide in ground vases and do not permit anything larger to be set on the grave. They can reserve the right to remove anything that is not in compliance with their guidelines. Avoid glass containers, and use containers that will withstand the elements.