December Gardening Activities - Region 5

Gardening Tips for December

Rocky Mountain and California Mountain Gardens

Learn2Grow Region 5 Map

States in the region:

Utah, Colorado, Wyoming, Idaho, California (Mountains)

Key Issues for December

  • Delight children this holiday season with the gift of gardening! Growums garden kits are designed to show kids and adults alike how awesome and easy it is to grow their own vegetables and herbs – and they encourage kids to eat healthy foods! Six fun garden themes are available (Herb, Pizza, Ratatouille, Salad, Stir-Fry and Taco), as well as three mini kits (Fruit Cup, Melon Blast and Pumpkin Patch). Visit to learn more!
  • Help your cut Christmas tree last through the holidays: Keep it moist and choose a spot away from drying air ducts and any heat sources, including TVs, radiators and fireplaces. (Remember, dry plant material is a fire hazard! Keep your trees watered and fresh.)
  • Enliven your dull winter garden or patio: Fill outdoor planters with cut greens. (Branch cuttings of holly, pine, spruce, juniper and other greens and berries may even increase bird activity on your deck or balcony.) Just be sure that the containers and urns you use are winter-hardy – ones that won’t crack or shatter in freezing temperatures.
  • Continue to water trees and shrubs, as long as the ground isn’t frozen. When it starts getting to that freezing point, drain your garden hoses and store them (coiled compactly) in the garage or basement. Take note of any that need replacement or repair. Do keep at least one hose handy for watering during any periods of warmer weather this winter. If there’s a thaw, you should water – especially evergreens.
  • Deck the halls with a traditional holiday favorite: the poinsettia. Today’s beauties come in a variety of colors, including the classic red, as well as shades of white, pink, purple and mottled/spotted. (Fun fact: The poinsettia is actually a medium-sized deciduous shrub native to western Mexico!)
  • Buy cyclamen, amaryllis (in bud) and other holiday plants early, so you’ll have weeks – not days – of enjoyment.
  • Give a personalized, inexpensive gift for the holidays that keeps on growing: seeds from your garden! Homemade holiday cards and ornaments containing seeds are as fun to make as they are to give – and grow!
  • Consider buying a balled-and-burlapped or container Christmas tree that you can enjoy inside your home, then make a permanent part of your landscape after the holidays. Keep the tree outside until you’re ready to bring it indoors (7-10 days inside). Plant it after the New Year – and remember to water!
  • Try the Norfolk Island pine as a containerized Christmas tree. This tropical plant is native to Norfolk Island east of Australia. (A bright-light indoor spot is a must for this beauty!)
  • If you haven’t done so already, take the time to clean your digging tools and sharpen pruners, garden hoes and shovel blades. (A nice present for the other home gardeners in your life is to have all of their tools professionally sharpened, too.)
  • Consider adding snowberry (Symphoricarpos albus) to your landscape. This adaptable native plant resembles popcorn, featuring an abundance of clustered, white fruits that accompany fuzzy, medium-green leaves from late summer into winter (and remain for several weeks after leaf drop). Birds are often attracted to the fruit, making this small, deciduous shrub a viable food source for winter wildlife.
  • If needed, apply horticultural oil as a dormant application on fruit and ornamental trees and shrubs. This smothers any potential insects that want to overwinter on desirable plants. Always read and follow all label directions and warnings carefully before you spray, and apply the product when air temperatures will be above freezing for 24 hours after the application.
  • Take care of our feathered friends. A source of fresh water and food will encourage them to your landscape. Keep feeders stocked so birds don’t have to search for food. If you have a birdbath, consider getting a birdbath heater to avoid frozen water in the colder areas of your region. If you’ve never tried feeding birds before, go the festive route: Creating a holiday bird-feeding tree is a fun way to get started!
  • Care for your roses: Apply protective mulch to them once the soil is frozen. Consider a light, airy mulch (like pine needles) to protect your plants from alternating periods of freezing and thawing. Roses with long canes that can whip around in winter winds can be pruned back 1/3 of their length, but avoid the urge to do any hard pruning just yet. (That work is better done in early spring, before bud break.)
  • Winterize your lawn equipment. After that final mow of the season, run your lawn mower dry of any remaining fuel, hose off grass clippings, pull the spark plugs, then park the mower in the shed or garage for a well-deserved winter’s nap. (You’ll be a step ahead next spring if you have the blades sharpened over winter, too.)
  • Bring all your outdoor terra-cotta pots back indoors (or to another sheltered location) so they won’t crack and break in winter’s cold. Empty those that are filled with spent, dead plants and clean containers with 9 parts water to 1 part bleach. Let the pots soak in this solution for at least an hour (or even overnight) to remove any stubborn residue. Rinse, dry and store them away for winter, so you’ll be ready to plant come spring.
  • Walk around your garden (while the weather’s still acceptable) and make any final notations about this year’s gardening successes and failures. By the time spring rolls around, you’ll have forgotten about the good, the bad and the ugly! Keep your pictures and notes in one accessible location – like in a garden journal. (You’ll be thankful you did when gardening catalogs start appearing in your mailbox.)
  • Help your houseplants in winter by allowing them to “rest” for a few months. Avoid fertilizing until late February.
  • Get a compost keeper for the kitchen. (Consider adding it to your holiday “wish list.”) Some produce scraps you’d otherwise throw away can be used to make great compost for your spring garden.