The telltale sign of spider mites is many white or yellow dots on the top of fan leaves. If the infestation is really bad, there will be webbing on the buds. Actual spider mites appear on the underside of fan leaves as tiny white dots, hard to see with the naked eye.
Here are some basic guidelines for keeping cannabis plants healthy and pest-free:
You can spray weed plants with safe, approved insecticides to get rid of spider mites. Be sure to check your state’s list of approved insecticides.
Root aphids in cannabis
They’re hard to spot with the naked eye, but infested cannabis plants show little white dots on the back of leaves. Spider mites also spin little webs, so if you see anything that looks like miniature cobwebs on top of marijuana leaves, it’s likely spider mites.
A severe infestation will lead to pale foliage and a general loss of vigor that will leave plants susceptible to disease, especially root rot. Adult gnats do not directly harm the plant, but they are vectors for disease, and also easily get trapped in resinous flowers—nobody wants to smoke bugs in their buds.
However, pyrethrum—derived from chrysanthemum flowers—is a natural insecticide that is very effective at killing mites. Three applications at 5-10 day intervals should significantly knock down and even eliminate spider mites.
Fungus gnats are grey or black long-legged flies 2-4 mm long, and they resemble tiny mosquitoes. Their larvae are white or transparent, 4-6 mm long, and live in soil where they feed on roots, organic matter, and fungus.
It’s time to fight back against cannabis bugs, mold and pests!
Slugs / Snails
Slugs and snails usually come out at night, leaving holes in leaves with scalloped edges from their individual bite marks. They also leave slime trails on leaves and on the ground.
If you want a list of safe, all-natural pesticides that can get rid of most of the pests on this list, check out this page: https://www.growweedeasy.com/safe-cannabis-pesticides
These bugs come in almost every color known to man so sometimes it can be tough to tell what they are just from looking. However, they all make clusters of spots on your leaves where they’ve sucked out all the sap, so if you see spots like this you know you’ve got leafhoppers!
Leaf Septoria / Yellow Leaf Spot
This fungus causes round yellow or brown spots, with symptoms often starting on lower parts of the plant