nurtomi

Too much fertilizer

Excess salts can injure roots and leaf edges.

Fertilizer damage on a cannabis leaf; brown tips have other possible causes.
Fertilizer damage on a cannabis leaf; brown tips have other possible causes. Photo: Fenrisulfir · CC BY-SA 3.0 · Resized and converted for display.

What to look for

Consider recent fertilizer use, crusts on the potting mix and brown tips or margins. These signs also occur with other problems, so check watering and roots before assuming fertilizer is the cause.

What to do

Pause fertilizer and check drainage. If the mix is not waterlogged and the plant tolerates it, flush the pot with fresh water and let it drain fully. Resume feeding only as appropriate for the plant and product label.

Sources