Yes,they defiantly work wonders,a handful in each hole will work magic for the plants,perfect if u have numerous plants that u want to set and forget until later in the season, just make sure there are no crystal on the first few inches of soil as they expand greatly when they are wet,if they are on the top few inches they can push out of the ground when they swell
an 8lb bucket is only $80 and they go a long way,some come with no fertilizer and some come with a 7-7-7 fert, I have never used the one with ferts,I personally use the soil moist brand