Aloe greatheadii is much like aloe globuligemma. They make excellent garden plants especially in the drier regions of South Africa. Being a succulent it is water-resistant and it is frost resistant making it able to survive in extremely cold conditions.
If overwatered it will damp off instead of germinating well. Use a mixture of river sand, soil and compost to sow the seeds. Sprinkle evenly and cover with a layer of small pebbles. Keep your seed tray in a warm dry corner and do not allow it to dry out. You may transplant the seedlings after one year.
To cultivate by cutting remove the offspring from the parent with a sharp pruning knife. Place the cuttings in the same mixture that you would use for the seeds, but add a top layer of river sand and use a root hormone to stimulate root growth.
If you are using damaged plants for cultivation use a fungicide to treat the damaged roots and stems. Let the wound dry out and heal for a few weeks before planting.