You made a tiny mistake when randomising flower offset, and instead of offsetting Z you are offsetting the Y axis.

Right now I'm seeing partially floating / burried flowers, but put them in a row along the X axis, and you will see them all line up perfectly, without any shift in their Z position.

Good job me! Thanks, will fix.

easy mistake to make, especially when working with variables that are not explicitly named 'axisX' or some such.

I did notice you kept the Y randomisation, you might want to limit how much it can randomise upward, cause I noticed one of my flowers floating above the block, and it looks strange that way (downward is not a big deal, and does indeed look nice)