Birds live in trees, so you may wonder how plants can harm your cockatiel, but the fact remains that some plants are toxic to your pet, even if your bird doesn’t know it and may try to nibble it. The following listing shows plants to keep away from your cockatiel and vice versa.
| Avocado | Lobelia |
| Black locust | Lupine |
| Clematis | Oleander |
| Crown vetch | Philodendron |
| Dieffenbachia | Poinsettia |
| Eggplant | Rhododendron |
| Foxglove | Rhubarb leaves |
| Hemlock | Virginia creeper |
| Lily of the valley | Yew |