Gladiolus are really a corm and not a bulb.* That's why they look so small.* There are hardy glads and tender glads.* The hardy ones will return each year but don't look much like their tender relatives which are tall with lots of flowers to a stem.
This site will explain how to grow your glads.
When weeding, the best way to make sure you are removing a weed and not a valuable plant is to pull on it. If it comes out of the ground easily, it is a valuable plant.