The long, elegant stems bursting with blooms of the gladiolus has always been a favourite to grow in the garden and as a cut flower for floral arrangements. Grown from a bulb, the gladiolus is available in a rainbow of colours. New hybrids of gladiolus are continually being developed to offer not only more variety of colour, but also in size and hardiness. Gladiolus can be grown in full size with flower stems reaching over 90 cm (3 feet) tall, dwarf gladiolus with much shorter stems, or hardy gladiolus, with patterned petals and the ability to withstand cooler soil temperature, unlike traditional gladiolus.
Fresh cut gladiolus stems can have a vase life of six to 12 days, depending on several conditions. From a vendor, select straight, strong stems that are fresh and have flower buds just on the verge of opening will prolong your gladiolus' vase life. Only the first two or three floret buds at the bottom of the stem should have the appearance of getting ready to open and bloom. From your garden, you should cut gladiolus stems that have several buds one quarter to one half open.
As soon as you have cut your gladiolus stems, condition them by placing the cut stems in a mix of water and floral preservative. Be sure the water is warm; gladiolus blossoms will not fully open in cool or cold water or temperatures. Place the container of gladiolus in a dark, cool location for several hours to harden off the flowers before making your flower arrangement. Cut 2.5 cm (1 inch) of stem off with a sharp knife and immediately place the cut stem in a solution, according to directions, of floral preservative and non-fluoridated water. Gladiolus are sensitive to fluoride, which causes petal damage and unopened florets.
To keep your cut gladiolus looking fresh, check the water level daily since gladiolus are heavy consumers. Change the water and preservative mixture every two to three days, remembering to use non-fluoridated, warm water. When you change the water mixture, trim the bottom of the stems by one inch to reopen the stem for better water uptake. Pinch off any dying blooms to keep the gladiolus visually fresh. Make sure you place your fresh cut gladiolus away from any ripening fruit or vegetables because the gas ethylene emitted from fruits and vegetables will quicken the demise of your flowers.