How to recognise fungus gnats (sciarid flies), why they appear and how to get rid of them in a cannabis grow with correct watering, yellow sticky traps, nematodes and Bti.
How to spot hermaphrodite cannabis, why a female plant grows male flowers and what to do to limit seeds in the buds, with the key prevention measures.
Why weed leaves curl down or up or droop, how to tell thirst from overwatering, and a quick checklist to find the cause and fix it.
How to spot spider mites on weed, why they multiply in warm, dry air and how to get rid of them with mechanical and biological methods, including during flowering.
How to recognise grey mould (botrytis) in hemp buds and prevent it in the grow tent, outdoors after rain and during drying and curing.
How to tell which nutrient is missing, or in excess, from the symptoms on hemp leaves, and how to correct it without making things worse.
Why hemp leaves turn yellow, how to find the cause from where the yellowing starts, and when it is perfectly normal, as in late flowering.