You can plant a bulb upside down
In the upper photo at left, you can see how similar the top and bottom of a gladiolus (Gladiolus hybrids) corm look. Sometimes you just can’t tell which side is up. Or you might be in a hurry and accidentally drop one in its planting hole with the basal plate — where the roots form — pointing up.
But, as you can see in the lower photo at left, it doesn’t make a difference. A few weeks after planting, the upside-down glad was growing at the same rate as the one planted right-side up. And if left in the ground, it looks like it would have righted itself — notice how the new stems are even beginning to turn the bulb over? While it’s not the best way to plant, setting a bulb upside down won’t prevent it from blooming.