Dendrobium orchids are not only exotically beautiful they are long-lived flowers both on the plant and when harvested as a cut flower. Whether harvesting a bloom at the peak of beauty or cutting down the stem of a spent flower to encourage rebloom, a few household items are all you need to do the job properly.
Prepare clean cutting tools by wiping the blades of your secateurs or scissors with cotton wadding doused in isopropyl alcohol. This will prevent bacteria transfer onto the living tissues of the dendrobium orchid plant.
Cut down a dying dendrobium flower stalk when all the blooms have dropped off and at least three-fourths of the length of the green spike stem has turned brown and desiccated to a crispy state. Orchids can recoup nutrients and moisture stored in the stem as the flower dies so always wait to cut the flower stem until it resembles a dried brown twig.
Harvest fresh dendrobium blooms by cutting down the thin flower stalk with clean sharp secateurs or scissors. Place the cut low on the stem just above where the thin green stem connects to the wide fleshy segmented pseudobulb. Be careful not to cut into or near the flesh of the pseudobulb.
Plunge the fresh cut bloom immediately into a vase of cool water treated with one to two drops of household bleach and a teaspoon of sugar. The bleach will kill bacteria in the vase and the sugar will feed the bloom. Replace the water and preservatives every day or every other day to prolong the life of the cut orchid.