Hi skeeziks,

The sun/shade thing is just serendipitous, (maybe weaker bulbs or smaller varieties just happened to end up there or there are other garden conditions in play).

Asiatics in particular like full sun and while Orientals can tolerate some shade they need to get ~ 4 hours of direct sun to do well. You are correct to feel that the situation should be reversed. In fact, the lilies planted under lots of trees receiving only dappled shade are not going to do well at all (sorry!). They may do OK for a year or two but will peter out. I wish it were different since most of my yard is the same type of shade as yours. I'm planting Maryland woodland natives in those areas.

Your soil also sounds fine. I have the same clay you do and have even gotten lilies to grow pretty well without amending. (And Mid-Atlantic clay is pretty tough stuff!) With amendments it should work well. Just be sure that with the clay that they are not planted in a "wet spot".

As for potential culprits,

Late Planting:
When in the Spring did you plant these bulbs? If you planted them in early Spring (mid April) your asiatics should have already bloomed by now. If you planted them is late Spring they could be way off schedule. Orientals are much later (normally bloom mid July - August) and if they were planted late would be even later than normal. Are you sure they have stopped growing?

Bulb Condition:
What size were the bulbs? (Small bulbs = small plants with few if any buds.) Did they have any roots? Were they moist? Were these bulbs intended for Spring sale (or Fall leftovers), did it look like they sat on the shelf for a long time. Lily bulbs don't go fully dormant and so shouldn't be out of the ground for long periods unless packed away with moist peat moss and refrigerated over the winter. A stressed bulb puts its energy into growing new roots and recovering and sometimes doesn't put up foliage at all the first year.

Bulb Variety:
In addition to being short are the short plants also immature looking (thin stems and smaller leaves)? If immature that indicates a small bulb. If not, there are pixie asiatics that only get 1 foot tall when full grown.

If you bought one of those mixed boxes of bulbs from a Sam's Club or other large chain retailer, they sit on the shelves WAY longer than they should, the bulbs are usually tiny compared to what you get from mailorder bulb companies, dry, and have little to no roots. The good news is that hybrid lilies can take a great deal of abuse and come back and perform well. Believe me, I had some Home Depot oriental bulbs I did everything in my power to kill and they are currently 5'-6' tall and full of buds.

Next year you will probably discover that your lilies in part sun do great. If you decide to move the lilies that are in shade wait until their foliage dies back in the Fall.

-Helen

My bulbs were from Sam's, and I (mistakenly?) planted them last fall. Are you saying there is a chance that next year I'll have some flowers in addition to the beautiful foliage? Should I leave them alone?

Thanks.

I don't think you mistakenly planted them in the fall. I have always planted mine in the fall. Nurseries sell them in the fall. I've had trumpet lilies not come up at all after overwintering, and I've been told it is our midwestern clay soil because they don't prefer a quicker draining sandy soil. Asiatics are easy to grow. My asiatics have always been in part sun and done fine. I can't speak for the non blooming problem. Never had that happen. Lilies do bloom more profusely with each passing year.