Hi, Debbie > I don't use grit on anything because a fine layer of grit on the top of any pot of bulb seeds will turn into a thin layer of cement as soon as the temperature reaches 89F here From this I assume you use a "grit" that includes the "fines" or sand. It is also possible to get what is called (for instance) 3/8 "open", meaning the largest particles are 3/8", and the smaller pieces, or "sand", are sieved out. If you can't get a larger "grit" size, try sifting out the smaller particles. An aquarium supply store often carries "aquarium sand" in larger sizes-1/8 to 1/4". If you have access to a farm store, ask what they have for poultry or chicken grit. I use pumice for pot toppings for most things that will germinate while it is still raining, but pumice will dry out and blow around in the summer, so for anything that takes a while to germinate, "grit" is a better choice. I'm still amazed, after years of seeing it, at how much cooler it is, and how much moister, below a few inches of either one. Ken