When can I return to work after having a lumbar discectomy?

Depends. Most discectomy patients can return to a sedentary job within 3-6 weeks. Patients with physical demanding jobs may require reconditioning afterwards and may have a slightly longer return to work.
2-6 weeks. To a degree, it depends on what you do at work. It also depends on your surgeon's preference. In general, if your work is sedentary, you can usually return in 2-3 weeks. For moderate work, 4-6 weeks. For very strenuos work, 6-8 weeks.