Troubleshooting
Heavy Metal Switch Grass problems — and how to fix them
Heavy Metal Switch Grass (Panicum virgatum 'Heavy Metal') is generally forgiving once you match its basics, but a few issues come up again and again. Here is what each one looks like, why it happens, and the fix.
Loss of upright form
The hallmark stiff stems splay open in shade or rich soil; plant in full sun and withhold fertiliser to keep it columnar.
Faded blue colour
The steel-blue tone weakens in shade; a fully sunny position maximises the metallic cast that gives the cultivar its name.
Self-seeding
Can produce seedling volunteers in good conditions; remove seed heads in late winter if you want to prevent self-sowing.
Rust disease
Rust pustules may develop in humid, congested plantings; divide overcrowded clumps and improve airflow to limit it.
Prevent heavy metal switch grass problems before they start
Most heavy metal switch grass issues are care-mismatch, not bad luck. Dial in the basics:
Looking for heavy metal switch grass in general rather than its problems? Read the full heavy metal switch grass care guide — light, water, soil and feeding.
Heavy Metal Switch Grass problems — FAQ
Why is my heavy metal switch grass loss of upright form?
The hallmark stiff stems splay open in shade or rich soil; plant in full sun and withhold fertiliser to keep it columnar.
Why is my heavy metal switch grass faded blue colour?
The steel-blue tone weakens in shade; a fully sunny position maximises the metallic cast that gives the cultivar its name.
Why is my heavy metal switch grass self-seeding?
Can produce seedling volunteers in good conditions; remove seed heads in late winter if you want to prevent self-sowing.
Why is my heavy metal switch grass rust disease?
Rust pustules may develop in humid, congested plantings; divide overcrowded clumps and improve airflow to limit it.