A sure sign that summer is near is the sweet aroma of lilacs waffling through the air. The lilac is a shrub of the genus Syringa. There are more than 1,000 varieties of lilacs, and they come in various colours and sizes. But these vibrant flowers don't last long; the average lilac bush only blooms a few weeks each year. And once cut, the typical blooms last five days. If you enjoy bringing your lilacs indoors, a little preparation will help keep your cut lilacs fresh as long as possible.
Choose the stems. Always choose lilac stems in the morning when they are filled with moisture from the morning dew. Warm days dehydrate flowers. Those cut at the end of the day will not recuperate from the cut and will probably have a short vase life. Look for stems with firm leaves and strong colours. To maximise vase life, choose stems with at least one-third of the flowers still in bud.
Cut the stems. Using a sharp knife or pruning shears, cut each lilac stem approximately 1 inch from the bottom of the main stem at a 45-degree angle. Cutting at an angle will help the stems stand in the vase and ensure a larger area is exposed to water for maximum water uptake. Remove any leaves, and immediately place the lilac stems into a plastic bucket of warm water with floral preservative. Cut flowers that are not provided water quickly will seal up, and the flowers will not last as long.
Prepare the stems. The key to long-lasting lilac arrangements is to move water and nutrients through the stems as soon as possible. Woody stems of lilacs do not take up water easily. To increase surface area for maximum water absorption, use a sharp knife or shears to split the end of each stem upward approximately 1 inch. Do not smash the stems with a hammer or you'll damage the vascular tissue.
Arrange the flowers. Put the prepared lilac stems in a vase of water combined with floral preservative. Floral preservative will combat bacteria, adjust water pH and provide carbohydrates necessary for a longer vase life. Double-check that no leaves or flowers are submerged in the water. Submerged foliage will retard bacterial growth, leading to foul-smelling water and a shorter vase life. Be sure to pick the correct vase size. According to flower expert Rose Edinger, the height of the lilacs should not be more than 1 1/2 times the height of the vase. Keep the vase out of the direct sunlight.
Never use household scissors to cut lilac stems. Remove wilted flowers from the arrangement. Keep arrangements away from ripening fruit.