Question
The piece which broke off is close to 10 inches long (only 1-12 inch diameter). How deep should I put it in the pot?

Answer
Robin,

After letting it "heal" for at least a couple of weeks, you can plant it about 3 inches deep in the soil. Water it, then don't water again until the soil is dry. If the cutting roots, it will take about a month or more, so be patient. Hope this helps.

Sincerely,

Greg