Are your plants in pots,or are they growing in the ground?If they are in pots,it will be easier for fertilization.If in the ground,poke holes around the base of the plants,maybe with some bailing wire or something,and use a liquid fertilizer around Easter time in your area.Only feed them twice,though-Lewisias don't like overly rich soil.

Thanks for the reply, but my question about bloom habit versus growth habit remains unanswered.

My plants are in the ground, and grow like weeds without any fertilizer.

My plants do the same thing, the ones that form clumps seem to bloom a lot less than the singles. But it must take a lot of energy to make all those pups. I have also noticed that the plants divided from the "clumpers" keep that growth characteristic and keep clumping and blooming less...

Thanks, Hap. I may root a few pups of my favorite bloom color and just keep breaking off the rest.

The fellow at Rare Plant Research said the same thing--the growth/bloom habit of any Lewisia plant depends on the original clone's habit.