OR...you could take lemons and make lemonade by limbing them up from the bottom and exposing those trunks. Some of the prettiest tree form hollies I've ever seen were Nellies.

I would resist any temptation of pruning out the trunks.

Nellie R. Stevens are typically multi-trunked. If your trees are young, they might appear weak to you because they just haven't hit their stride. Regardless of the characteristic multiple trunks, yours will grow into the typically loose pyramid shape and should keep their dense, symmetrical shape without pruning.

Newly purchased stock often grown fast by grower trying to turn it over as fast as possible, with more normal growth resuming in purchaser's landscape.

Thanks for the replies, it helps. I can very much resist pruning them since it's their natural shape I love. I did not realize nellie stevens had multi trunks, my growing experience has been American Hollies - which I never, ever pruned - with a single trunk. I prefer the dense foliage of the NS. I had been reading that you can turn a NS into more of a shrub by pruning the daylights out of it, so was concerned I bought shrub forms, but I want trees. The ones I bought are very healthy, and here I am planting the poor things right before summer. I'd hate to prune on top of that.

I am considering planting Nellie Stevens Holly for privacy on my property. However, I have powerlines that cross the property and the restriction is 15'. My question is whether I would be able to keep the Nellies limited to 15' by pruning/trimming.

I have a few Nellie stevens hollies that were too close to some other shrubs so the sides are flat where they couldn't grow correctly. I have since removed those other shrubs and left the hollies. How do I reshape them to the pyramid that they should be?