Cutting at the right stage of development is the most important factor in how long a flower lasts in the vase. Cut too early and buds may not open; too late and petals drop within a day. Each flower has a specific ideal stage.
Harvest in the early morning or late evening when stems are fully hydrated. Bring a clean bucket of water to the garden and plunge stems in immediately. Use sharp, clean pruners or snips—dull blades crush stem cells and reduce water uptake. Cut stems longer than you think you need; you can always trim later.
Spike flowers (snapdragons, larkspur, stock, delphinium, foxglove): Cut when the bottom third of the spike is open.
Multi-petal focal flowers (dahlias, peonies, ranunculus): Cut at the marshmallow stage—buds that give slightly when squeezed.
Daisy-type flowers (zinnias, cosmos, rudbeckia, sunflowers): Cut when petals are upright and the center is still tight. For zinnias, use the "wiggle test"—if the stem is stiff below the bloom, it is ready.
Cluster flowers (yarrow, ageratum, celosia): Cut when three-quarters of the cluster is open.
Bulb flowers (tulips, daffodils, anemones): Cut in bud showing color. They open fully in the vase.
Get stems into water immediately. Move the bucket to a cool, dark place for at least 2–4 hours (or overnight) to let flowers hydrate fully before arranging. This step alone can add days to vase life. See conditioning for next steps.