January gardening guide: What indoor and outdoor plants need for an Oregon winter

OSU Extension offers timely guidance on pest control, fertilization, garden maintenance, and other topics. Not every region in Oregon will benefit equally from these suggestions. Get in touch with the Extension office in your area for further details.

Sustainable gardening techniques are promoted by the Oregon State University Extension Service.

Instead of using reactive pest treatment, use preventive pest management. Prior to taking action, identify and track issues, then choose the least harmful course of action. Predators and parasitoids that consume insect pests are examples of biological control agents that should be preserved.

Planning

• 
  Plan to replace varieties of ornamental plants that are susceptible to disease with

  resistant cultivars

  in February.
  

• 
  Take

  hardwood cuttings

  of deciduous ornamental shrubs and trees for propagation.
  

• 
  Order a soil test to determine your garden s nutrient needs. Contact

  your local Extension office

  for a list of laboratories or view

  Analytical Laboratories Serving Oregon.

• 
  Begin planning this year s

  vegetable garden

  in western Oregon and

  central Oregon

  . Check with local retail garden or nursery stores for seeds and seed catalogs.
  

• 
  Keep a garden journal. Consult your journal in the winter, so you can better plan for the growing season.
  

Maintenance and cleanup

• 
  Central/Eastern Oregon: To prevent winter damage from drying, water plants deeply every six to eight weeks, when the temperatures are above freezing.
  
• 
  Place windbreaks to protect sensitive landscape evergreens against cold, drying winds.
  
• 
  Reapply or redistribute

  mulch

  that has blown or washed away during winter.
  

• 
  Clean pruners and other small garden tools with rubbing alcohol.
  
• 
  Western Oregon: Water landscape plants underneath wide eaves and in other sites shielded from rain.
  
• 
  Western Oregon: Do not walk on lawns until frost has melted.
  

Pest monitoring and management

Read the pesticide label carefully and only use chemical controls when absolutely required. Think on cultural controls first, followed by biological and physical controls. Select the least harmful options and use them sparingly. Horticultural oils, insecticidal soaps, botanical insecticides, and both synthetic and organic pesticides are a few examples.

• 
  Scout cherry trees for signs and symptoms of bacterial canker. Remove infected branches with a clean pruner or saw. Sterilize tools before each new cut. Burn or send the branches to a landfill before bloom. See

  Managing Diseases and Insects in Home Orchards

  .
  

• 
  Watch for field mice damage on lower trunks of trees and shrubs. Eliminate hiding places by removing weeds. Use traps and approved baits as necessary.
  
• 
  Use dormant sprays of lime sulfur or copper fungicide on roses for general disease control, or plan to replace susceptible varieties with

  resistant cultivars

  in February.
  

• 
  Western Oregon:

  Moss in lawn

  may mean too much shade or poor drainage. Modify site conditions if moss is bothersome.
  

• 
  Mid-January: Spray peach trees with approved fungicides to combat

  peach leaf curl and shothole

  . Or plant curl-resistant cultivars such as Frost , Q1-8 or Creswell .
  

• 
  Monitor landscape plants for problems. Don t treat unless a problem is identified.
  

Houseplants and indoor gardening

• 
  Monitor

  houseplants

  for correct water and fertilizer; guard against insect infestations; clean dust from leaves.
  

• 
  Protect sensitive plants such as weeping figs from cold drafts in the house.
  
• 
  Propagate split-leaf philodendrons and other leggy indoor plants by air-layering or vegetative cuttings.
  
• 
  Plant dwarf annual flowers such as coleus, impatiens and seedling geraniums inside as houseplants.
  
• 
  Western Oregon: Gather branches of quince, forsythia and flowering cherries and bring them indoors to force an early bloom.
  

Trade-name goods and services are solely used as examples. The Oregon State University Extension Service does not support these goods and services or aim to discriminate against those that are not listed.

Extension Service at OSU