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Your Winter Garden: Pest tips for houseplants

By Julie Weisenhorn, Extension Educator - Horticulture

Just like in our summer gardens, we need to keep an eye out for pests in our indoor winter gardens (houseplants). Pests may sometimes hitchhike on houseplants that spend the summer outdoors, and emerge in the warmth of our homes. New plants may also bring in new pests. Insect eggs laid on the underside of leaves or in the soil may hatch indoors and suddenly appear too.

Hand showing plant debris accumulated on the soil of a potted plant.
Remove plant debris
Tips to reducing pest issues in your winter garden:

Groom plants that come in from the outside. Clear away dead plant debris (leaves, flowers) and prune off dead or overgrown stems and branches. Remove dust that can filter light by wiping off leaves with a soft, damp cloth or spraying the plant with water.

Scout for signs and presence of pests.
Look at the undersides of leaves and along edges and the bottom of  pots for insects and egg masses and remove or treat. Shiny, sticky leaf surfaces (honeydew) can be a sign of sucking insects like scale and aphids. Fine webbing is a sign of spider mites. Household insects

Some plants may be outgrowing their containers and need re-potting. 
Take this opportunity 
to check the underside of the plant as well as
roots, and to prune off any roots that are dark brown and mushy.
Re-pot plants in fresh, sterile soil and a clean pot.
Use fresh soil and a clean pot.

Give new plants plenty of space. Quarantine new plants for a couple of weeks away from your current, pest-free plants to make sure the new fella is pest-free too.

Follow pesticide labels. Many pests can be eliminated from houseplants by hand-picking, wash or a blast of water. If you do choose to treat with a chemical, use one for houseplants and follow all pesticide label precautions. This is especially important with indoor plants as they live where we live. Household Insect Control
    Examine all parts of plants.
    Cottony scale on orchid
  • Look to treat outside on one of those warm winter days or in a ventilated garage. 
  • Bag the plant in a plastic garbage bag, and poke a small hole in the bag for your spray nozzle. Then spray, apply a piece of tape over the hole, and let the plant site covered. Remove the bag when the plant is dry. This contains the pesticide till dry and protects furniture and walls from spray. 

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