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Copper Deficiency

Problem: A cannabis copper deficiency is rare and manifests itself as leaves curling back, lack of growth, and unusual dark coloring of the leaves. Copper doesn't move easily through the plant and is considered "low-mobile."

Symptoms of New (Young) Leaves

  • Dark or twisted
  • Purple or blue undertones
  • Metallic sheen on leaves
  • Leaves turn under
  • Tips may turn yellow or white

Symptoms of Older Leaves

  • Older leaves may show signs of pale yellow or white

Other Copper Deficiency Symptoms

  • Buds do not ripen, or grow very slowly
  • Pistils (hairs) on female plants may not grow properly
  • Plant may wilt or have limp leaves
  • New growth has difficulty opening up

It is very unlikely that there is no copper available in your water or soil, so usually a copper deficiency in cannabis is caused by a pH problem at the roots that is restricting access to nutrients.

Often it is a problem with another nutrient or with the pH that causes the appearance of a copper deficiency.

This marijuana plant is showing signs of a copper deficiencyA close up of a cannabis plant that is showing signs of a copper deficiency with dark, twisted leaves

Copper toxicity (too much copper) in cannabis plants is rare, though a severe case of too much copper can cause a quick death to the plant.

Solution For Cannabis Copper Deficiency

If you suspect your growing cannabis plant has a copper deficiency, flush your system with clean, pH'd water that contains a regular dose of cannabis-friendly nutrients. This will remove any nutrient salts that may be affected the uptake of copper and help restore pH to the proper levels..

Watch to make sure that the problem starts to clear up within a couple of days. Old growth may not recover, but new growth should be healthy.

  • In soil, copper is best absorbed by the roots in the 6.0 - 7.0 pH range
  • In hydro, copper is best absorbed by the roots in the 5.5 - 6.5 pH range

If you cannot get rid of a cannabis copper deficiency, please consult our 6-Step Cure to 99% of Cannabis Growing Problems

Cannabis Copper Deficiency - Dark, twisted, unhealthy leaves -
Big Symptom Picture: 
Leaf Color: 
Pale Color Leaves
Yellow Leaves - Lower, older leaves
Dark or Purple Leaves
Leaf Symptoms: 
Upper Leaves / Newer Growth Affected
Lower Leaves / Older Growth Affected
Slow Growth
Twisted Growth
Abnormal Growth
Leaves Curl Under
Wilting / Drooping
Plant Symptoms: 
Weak Stems
Slow Growth
Twisted Growth
Leaves Curl Under