You're going to need more sun. I don't know how they would do in shade. I think if they did grow, they'd be floppy since they're so tall.

I have some alliums (unkown kind but not Gladiator) in a shady bed that was originally sunny. They grow each year but do not really flourish; do not always bloom and look wimpy when they do.

I too bought Gladiators so I hope you will get more answers! It's interesting to know you have successfully grown lilies there. It must be a tall tree and therefore enough light gets in from the sides.

Hi Keith. I have grown gladiators for 2 years in partial shade. They have been fine except that they grow so tall, about 5 feet, that I have to stake them in wet weather. I think they are one of the tallest alliums, but not the biggest ball. You might want to try the globemaster. I grow some in partial shade and some in full sun. They ones in partial shade don't get quite so big, but they are fine. The stalk in a sturdy 3' and doesn't need staking. The ball is HUGE! And it smells wonderful, too. I would research growing under Walnut trees, though. They poison some plants growing underneath them. Good luck!