May or June are good months to plant the corms or bulbs of gladiolas. The common glad is actually a tender bulb and will not return each year unless it is protected from winter freezing. There are different types of glads however and some are even winter hardy. After your glads bloom you can dig them up in the fall and store them indoors over the winter for replanting. In the Pacific Northwest glads may overwinter if you grow them in soil that is very well drained such as in a rockery or raised beds. Keep growing, Marianne Binetti