Also try this it monitors illuminates Nats and monitors at the same time. The Yellow paper believe it or not works really well…lay it flat under plant DO NOT! Let it touch your plant it’s extreamly sticky and won’t let go of leafs and stems.
Granules put in small lid or saucer bit of water under plant
Never used nematodes before
Don’t know if this works in Grobo but it works in my tents …something is to Moist NATS!