Tall, slender-neck bud vases are best suited to display flowers with naturally long stems or upright flowering clusters. The main concern when selecting a bloom for a tall bud vase is stability. You don't want a large, heavy flower or flimsy stem in a longneck vase as it may readily topple. Great flowers for a tall bud vase include roses, orchid sprays--especially oncidium, dendrobium and phalaenopsis--gladiolas, daises, daylilies, cosmos, irises, zinnias, snapdragons and larkspurs. Tulips and gerber daisies work well as long as their stems don't soften or elongate.
Too often the short, dainty flowering plants of the woodlands or early spring garden are not used in flower arrangements because they are diminutive or have weak stems. A short bud vase, such as one the size of a baby food jar can hold these delicate blooms. While a singular flower may look grand in a longneck bud vase, a cluster of small flowers has the most impact in a miniature bud vase. Prime candidates for filling it include violets, snowdrops, sweet alyssum, pansies, begonias, creeping phlox and miniature zinnias.
Accompany a flower in a bud vase by a sprig of foliage for added visual weight and interest. While you might think a bud vase filled with flowers is the only way to decorate, don't rule out using only attractive sprigs of plants with attractive leaves. The foliage could be particularly colorful--mimicking flowers--or architecturally intriguing. Ferns are a great specimen for a bud vase. Don't limit yourself, though, as David Pippin from Learn2Grow suggests, you can even create a collection of bud vases that highlight a different plant from your garden. Sprigs of herbs like rosemary or thyme can grace an appropriately sized bud vase, or use even clippings of evergreens and pussy willows for a wintery display.