An editorial image illustrating different stem cuts. It does not identify a cultivar or florist.
Cutting every flower stem diagonally is not a universal rule. Japan’s Ministry of Agriculture, Forestry and Fisheries gives the example of cutting firm stems such as roses diagonally under water, while softer stems such as sunflowers are cut straight across.
Firm stems: a diagonal cut under water
For a firm rose stem, MAFF describes making a diagonal cut in clean water. MAFF explains that the diagonal increases the cut surface and that making the cut under water helps the stem take up water.
Soft stems: a straight cut
For softer stems such as sunflowers, MAFF gives a straight cut as the example. Use a clean, sharp tool so the softer tissue is not crushed unnecessarily.
Match the water depth to the flower
MAFF gives deep water—about half the vase—for roses and shallow water for sunflowers and gerberas as examples. Do not use one water depth for every flower; follow flower-specific advice from the shop.
Cleanliness matters for both
- Wash the vase and cutting tool first.
- Remove leaves that would sit below the waterline.
- Rinse slime from the stems.
- Replace old water instead of topping it up.
A slimy cut surface can indicate bacterial growth and poor water uptake. Rinse the stem, recut a small section with a clean blade, and refresh the vase water.
Follow flower-specific advice
Treatment can vary with species, cultivar, condition, and stem thickness. When the florist provides instructions, follow those rather than a general rule. If unsure, tell the shop the flower name and describe the stem.
Sources: MAFF, Handling Cut Flowers for Longer Vase Life; MAFF Kanto Regional Agricultural Administration Office, Basic Cut-Flower Care
