Cannabis plants are magnets for pests and mold. Whiteflies and spider mites can transmit viruses, destroying plants. Molds can kill plants or linger on harvested plants, getting into the lungs of those who smoke the infected plant.

Some growers control these with predatory insects, natural oils and chemicals made by bacteria. No pesticides are federally approved for cannabis and California restricts what can be used. Weed tests show growers using prohibited pesticides, including smoke fumigants, bug bombs and growth hormones. Plants also can be contaminated by pesticides in the soil and air, including drift from nearby farms.

Pesticides absorbed by plants can be concentrated when stems and leaves left after harvest — sold in bulk as cannabis biomass — are processed into high-THC concentrates used to make vapes, edibles and other products.

Cannabis plants are magnets for pests and mold. Whiteflies and spider mites can transmit viruses, destroying plants. Molds can kill plants or linger on harvested plants, getting into the lungs of those who smoke the infected plant.

Some growers control these with predatory insects, natural oils and chemicals made by bacteria. No pesticides are federally approved for cannabis and California restricts what can be used. Weed tests show growers using prohibited pesticides, including smoke fumigants, bug bombs and growth hormones. Plants also can be contaminated by pesticides in the soil and air, including drift from nearby farms.

Pesticides absorbed by plants can be concentrated when stems and leaves left after harvest — sold in bulk as cannabis biomass — are processed into high-THC concentrates used to make vapes, edibles and other products.

Cannabis plants are magnets for pests and mold. Whiteflies and spider mites can transmit viruses, destroying plants. Molds can kill plants or linger on harvested plants, getting into the lungs of those who smoke the infected plant.

Some growers control these with predatory insects, natural oils and chemicals made by bacteria. No pesticides are federally approved for cannabis and California restricts what can be used. Weed tests show growers using prohibited pesticides, including smoke fumigants, bug bombs and growth hormones. Plants also can be contaminated by pesticides in the soil and air, including drift from nearby farms.

Pesticides absorbed by plants can be concentrated when stems and leaves left after harvest — sold in bulk as cannabis biomass — are processed into high-THC concentrates used to make vapes, edibles and other products.

Cannabis plants are magnets for pests and mold. Whiteflies and spider mites can transmit viruses, destroying plants. Molds can kill plants or linger on harvested plants, getting into the lungs of those who smoke the infected plant.

Some growers control these with predatory insects, natural oils and chemicals made by bacteria. No pesticides are federally approved for cannabis and California restricts what can be used. Weed tests show growers using prohibited pesticides, including smoke fumigants, bug bombs and growth hormones. Plants also can be contaminated by pesticides in the soil and air, including drift from nearby farms.

Pesticides absorbed by plants can be concentrated when stems and leaves left after harvest – sold in bulk as cannabis biomass – are processed into high-THC concentrates used to make vapes, edibles and other products.

Cannabis plants are magnets for pests and mold. Whiteflies and spider mites can transmit viruses, destroying plants. Molds can kill plants or linger on harvested plants, getting into the lungs of those who smoke the infected plant.

Some growers control these with predatory insects, natural oils and chemicals made by bacteria. No pesticides are federally approved for cannabis and California restricts what can be used. Weed tests show growers using prohibited pesticides, including smoke fumigants, bug bombs and growth hormones. Plants also can be contaminated by pesticides in the soil and air, including drift from nearby farms.

Pesticides absorbed by plants can be concentrated when stems and leaves left after harvest – sold in bulk as cannabis biomass – are processed into high-THC concentrates used to make vapes, edibles and other products.

Cannabis plants are magnets for pests and mold. Whiteflies and spider mites can transmit viruses, destroying plants. Molds can kill plants or linger on harvested plants, getting into the lungs of those who smoke the infected plant.

Some growers control these with predatory insects, natural oils and chemicals made by bacteria. No pesticides are federally approved for cannabis and California restricts what can be used. Weed tests show growers using prohibited pesticides, including smoke fumigants, bug bombs and growth hormones. Plants also can be contaminated by pesticides in the soil and air, including drift from nearby farms.

Pesticides absorbed by plants can be concentrated when stems and leaves left after harvest – sold in bulk as cannabis biomass – are processed into high-THC concentrates used to make vapes, edibles and other products.