Growing thryallis shrubs is not difficult if you live in the right climate. Find a location in your garden with full sun to help this bush grow best and produce the most flowers. Once your thryallis is established, it will tolerate drought well so watering is not usually necessary. Thryallis shrub care is not very labor intensive, one great reason to use it as an ornamental shrub. There are no known pests or diseases to worry about and not even deer will nibble on this shrub. The only maintenance you may need to perform is occasional pruning. How much you prune it and how often will depend on the formality you prefer. These shrubs can be trimmed into tight shapes, thanks to their density, but they can also be left to grow more natural and still look nice.