We highly recommend that you mulch your Tulip Poplar Tree with either a ground hardwood mulch or a ground cypress mulch depending on your local availability. Any type of mulch will do but cypress or hardwood mulch will be of a higher quality and provide better nutrition overall as they breakdown. Mulching helps to keep weeds away which will compete with your new investment for water and nutrients. A 2 to 3 inch layer of mulch is sufficient but remember to take care not to cover any part of the stem of the plant with mulch. Its better to leave a one inch gap of space between the mulch and the stem or trunk of the plant.