Janice: Pebble-sized clods of soil are too large. Since grass seed is a small seed, we need the soil to be as fine as possible to insure good seed to soil contact. A way to get around your problem of cloddy soil conditions is to add a soil amendment, such as potting soil, compost or any soil that can be easily worked to a fine consistency. According to our regional Extension horticulturalist, Dave Robson, grass needs to be seeded before the end of April. As I mentioned before, grass seed should have good seed to soil contact. After seeding, rake the seed in to get soil contact. Do not allow the seed to dry out, this may mean daily waterings and adding a straw mulch to reduce evaporation. I hope this answers your question.