The seeds, at least, have a near 100% germ rate. Stratified in fridge for 4 weeks and they germinated 4-5 days after.
It was easy to do as I purchased a nematode hose attachment sprayer that self emptied so i knew when i had used all the nematodes. As many reviews stated the best results would be to do it again in late September I phoned to order some more for that time period, and you only do the one order a year. It was disappointing as I wanted to make sure I got rid of the grubs as the racoons were tearing up my back yard.
Direct sowed these in May and had flowers by early July! So pretty and exactly like the pictures.
So far the Nematodes seem to be controlling all sorts of pests in our large open bottom galvanized raised beds. We noticed some early issues with leaf miner in the beets and turnips but since we applied the nematodes the damage has been drastically reduced. No cabbage root maggots in the crucifers planted in those beds either. We are still waiting to see if the carrots come up nice and pest free. Very happy so far.