Depending on the amount of artichokes you're steaming it takes between 25 to 35 minutes to steam the artichokes and then they'll be ready to eat.
If you have just a little bit of artichokes you're steaming such as for a single serving then steaming the artichokes for 25 minutes should be enough time.
But if you're steaming more than a single serving of artichokes at a time it can take up to 35 minutes for them to be fully done and ready to eat.
To steam the artichokes put the artichokes in a steamer basket, stem-side up and steam them until the heart is tender when pierced with a tip of a paring knife, and inner leaves pull out easily.
Artichokes can also be eaten raw if you want too eat them raw so they are safe to eat no matter how long you steam them for.