January Gardening Tips for the Willamette Valley

by Rod Smith

Former Iowa Certified Nurseryman and
Oregon Certified Nursery Professional

© 2002-2023 Rodney A. Smith
All rights reserved.

Winter Weather

Protect broadleaf evergreens from cold weather by covering them with bedsheets or plastic. Tender plants, such as waxleaf privet, fragrant daphne and pittosporum need protection from temperatures below 25 degrees. Almost all broadleaf evergreens need protection from temperatures below 15 degrees. Remove clear plastic if the sun comes out or plants will overheat. Black plastic can be left on the plants for up to a week without damage. Garden blanket can also be left on because it breathes.

Spraying broadleaf evergreens with Wilt-Pruf will protect them against windburn.

Brush snow off of plants with an upward motion so branches are not broken. Excessive ice can be melted off with water but watch for re-freezing.

Stored plants

Check stored dahlias, begonias and gladiolus. Sprinkle lightly with water if they are shriveled. Make sure they are kept between 33 and 40 degrees.

Check stored geraniums and fuchsias. The soil should be kept slightly moist, moist enough that plants do not shrivel, but dry enough that mold does not grow.


Now is the time to prune, shape and train fruit trees and grapes. Pruning removes weak or diseased branches and insures good air circulation to help prevent diseases. Summer flowering deciduous shrubs, such as hydrangeas and rose of sharon, also can be pruned now. Spring flowering shrubs, such as forsythia and lilacs, could be pruned now, but flowers will be cut off if they are pruned before they bloom. Wait until summer to prune plants that are too big, because winter pruning makes them grow even faster.


Slugs will be after the first thing that comes up - your early bulbs and perennials. Protect them with slug baits. The spray on formulas or Sluggo are safer for pets.

Many insects and diseases overwinter in branches, tree trunks, and plant debris. Dormant sprays can be the most important pest control of the year. Full strength mixtures of lime-sulfur and oil can be used when plants are dormant. Many insects and disease spores can be destroyed before they start to multiply. For best results, spray on a warm day with no rain or freezing weather expected for at least 8 hours.
WARNING!! If you click on a link and a blank screen opens, then connects to a strange website, especially if you see a robot, CLOSE THE NEW WINDOW IMMEDIATELY!! The links will work correctly after the first time.
January | February | March | April | May | June | July
August | September | October | November | December

hit counter