Those green bumps are likely roots starting to grow, but what's odd is why they're green - they should be white if they're not exposed to daylight, so maybe you didn't bury it properly? Just replant it and leave it alone; over time, hopefully, it will put out more roots and more topgrowth.
Looking again, the stump at the base of the plant is quite short; you say you buried the base under soil, but its possible that some light did get to the root nubs because of the shortness of the stump. Over time, they should grow on and become paler, but don't be tempted to look! You'll know over time if the plant has produced good roots because the top will start getting bigger.