Grow your own cat grass.Cats love to nibble tender, sweet oats. Sprouts in 3 -4 days.Growing is simple. Fill a shallow bowl or saucer with moist potting soil, sprinkle oats over the soil at about 10 seeds per square inch. Water regularly and provide plenty of light. Planting Tip: Pre-soak the oat seeds in warm water for 10 hours before planting.