Use them for cuttings or seeds.
A slice or two up from the bottom to about 3/4 inches from the top may help roots to grow faster.
These rockwool plugs feature a slit for easy insertion rooted cuttings. Ideal for growers using aeroponic EZ clone machines. They fit perfectly into the holes of any standard rockwool blocks, inserted into pebbles, or any other type of growing mediums.