Cannabis plant problems
Find what is wrong with your plant by what you see, then fix it. Not sure? Send a photo to the Grow Doctor.
Nutrients
- Carenza di azoto: Lower, older leaves turn pale green, then evenly yellow from the tip inwards
- Eccesso di azoto (l'artiglio): Leaves are very dark green, almost shiny
- Carenza di fosforo: Dark, dull or bluish green leaves with brown to purple patches, often on older leaves
- Carenza di potassio: Leaf edges and tips turn yellow, then brown and crispy, starting on older leaves
- Carenza di calcio: Small brown spots with sharp edges on new and middle leaves
- Carenza di magnesio: Yellowing between the veins of older and middle leaves while the veins stay green
- Carenza di ferro: The newest leaves turn pale yellow while their veins stay green
- Carenza di zolfo: New leaves turn evenly lime green or yellow, veins included
- Carenza di zinco: New leaves are small, narrow and wrinkled
- Carenza di manganese: Yellowing between veins on new and middle leaves with a thin green border along the veins
- Carenza di boro: Growing tips die back or grow hollow and twisted
- Bruciatura da nutrienti: Leaf tips turn yellow, then brown and crispy, a few millimetres in
- Blocco di pH: Several deficiencies at once: yellowing, spots and burnt edges together
Water and roots
- Eccesso di acqua: The whole plant droops with leaves that feel firm and swollen, not limp
- Carenza di acqua: Leaves hang limp and soft, like they have no strength
- Marciume radicale: The plant wilts even when the medium is wet
Light, heat and air
- Bruciatura e sbiancamento da luce: The top leaves closest to the light turn yellow or white while their veins stay green
- Stress da calore: Leaves fold upwards along the middle like a taco
- Stress da freddo: Leaves and stems turn purple (beyond what the strain normally shows)
- Aria troppo secca: Leaves curl and feel thin and dry
- Aria troppo umida: Water drops on leaves or walls in the morning
- Cime a coda di volpe: Small spires of new calyxes stack on top of the buds
- Piantine allungate e filanti: Long thin stems that fall over
- Bruciatura da vento: Leaves near a fan are clawed, dry or torn
- Ermafroditi e banane: Yellow banana shaped growths (nanners) appear between the buds
Pests
- Ragnetti rossi: Tiny white or yellow dots on the top of leaves
- Tripidi: Silvery, shiny scratches on leaves
- Moscerini del fungo: Small black flies around the soil surface
- Afidi: Clusters of small soft green, black or white insects under leaves and on new shoots
- Mosche bianche: Small white flying insects that rise when you touch the plant
- Bruchi e larve delle cime: Holes eaten in leaves
- Acari rugginosi e acari larghi: Leaves curl up at the edges and turn shiny, glossy or bronze
- Afidi delle radici: Plants stall and yellow without a clear reason
Diseases
- Oidio o mal bianco: White, flour like patches on the top of leaves
- Marciume delle cime (botrytis): A bud has brown, dry or slimy parts inside
- Macchie fogliari da septoria: Round yellow spots on lower leaves that turn brown with a yellow halo
- Collasso dei semenzai: A seedling suddenly falls over
- Avvizzimento da fusarium: Leaves yellow and wilt on one side or one branch first
- Viroide latente del luppolo (HLVd): Plants grow smaller than expected and stay stunted
Handling and timing
- Una pianta maschio: Small round balls on short stems where branches meet the main stem
- Shock da trapianto: The plant droops for a day or two after repotting
- Semi che non germinano: No taproot after 5 to 7 days
- Autofiorente stentata: An autoflower starts flowering while still very small
- Raccolto troppo presto o troppo tardi: Early: most trichomes are still clear, pistils mostly white, effect thin and racy