1. In a large saucepan or Dutch oven, cover dried peas with 2 quarts of water. Bring split peas to a boil; boil gently for 2 minutes. Set aside to soak for 1 hour.
2. Add ham bone, chopped onion, garlic, and pepper. Bring split pea soup to a boil; cover, reduce heat, and simmer for 2 hours, stirring occasionally.
3. Remove meat from bone; dice and return to pea soup with chopped celery and carrot.
4. Simmer split pea soup slowly for 45 minutes, stirring occasionally.
5. Taste split pea soup and add salt.