Article: Cut 1 inch (2.5 cm) off the stems at an angle and change the water every 2 days to keep the spikes and florets looking fresh. Use a sharp blade to slice off each end at an angle about 1 inch (2.5 cm) up the stem.  It’s important to clip them regularly because microbes will grow at the base and block the flow of water up the stem. If you notice the ends are slimy or dark green after snipping the end, cut it again about 1 inch (2.5 cm) at a time until you see a fresh base. Cut gladiolus will last anywhere from 6 to 12 days depending on the health of the plant when you cut it and how you take care of it. Plant food is made of sugar, an acid, and bleach; the mixture feeds the plants while keeping bacteria or mold from growing. Every time you change the water and snip the ends, stir some plant food into the water. The feed will give the flower more nutrients and keep it healthy for longer.  You can buy cut flower feed at any superstore or grocery store that has a plant nursery. You can also use half a crushed aspirin pill instead of flower feed. Inspect the stalks twice a week and pinch off any wilted or scraggly-looking florets. This will not only improve the look of the flowers but it will allow new, healthier blooms to grow.  Wilted florets will appear shriveled and limp or show signs of discoloration (like darkening or browning). Remove each flower as it begins to wilt—don't wait until the seed head begins to form. Take care to remove not just the shriveled petals but also the swollen bit at the base of the dead flower (where it connects onto the main flower stem). This is the bit that forms the seed.

What is a summary?
Change the water and recut the stems by 1 inch (2.5 cm) every 2 days. Feed your gladiolus with plant food with each water change. Deadhead your gladiolus twice a week to improve their appearance.