10 Gardening Activities for December in Southern California

1. Get a Living Christmas Tree

Consider buying a Christmas tree that will live on after the holiday season is over. One way to do this is by renting a tree that you can have delivered to you by a service such as The Living Christmas Co. They deliver live, un-cut trees in containers and pick up the trees at the end of the season. The company keeps the trees alive from season to season or they plant them in Southern California if they get too large. Another way to enjoy a living Christmas tree in your home is to buy one at your local nursery. Look for a large specimen of Aleppo pine, white spruce, blue spruce, Colorado blue spruce, deodar cedar, or other conifers that have a pyramidal shape. For an alternative tree, try a Norfolk Island pine. Then keep your tree alive from year to year or plant it in your garden when the holiday season is over.

2. Prune Trees Before Winter Storms

If you live in an area with high wind or snow, consider trimming any dead or broken branches. Falling branches can be a safety hazard and may destroy areas of your garden. For larger trees, it’s a good idea to hire a certified arborist. Find an arborist through the International Society of Arboriculture (ISA).

3. Continue Planting Natives & Mediterranean Plants

This is the middle of the holiday season, but for Southern Californians it’s also prime planting season. Continue planting California natives as well as Mediterranean plants. For natives, a few easy-to-grow beautiful plants include deer grass, coffeeberry, toyon, monkey flower, oak trees, California fuchsia, manzanita, and salvia (‘Celestial Blue’, ‘Pozo Blue’, or Salvia clevelandii). For Mediterranean plants try rosemary, olive trees, lamb’s ear, Jerusalem sage, rock rose, or Italian cypress.

4. Care for Avocados

Don’t feed your avocados this month as they are finished putting on new growth until early spring. The trees may also show some leaf drop, but don’t be alarmed. This is natural. Avocados drop leaves frequently, creating a natural mulch around the base of the tree. It’s often best to leave the leaf litter under the branches of the tree which helps keep the roots cool—something avocado trees prefer.

5. Add Garden Structure

As deciduous trees lose their leaves and the flowers of summer and fall fade, structural elements in your garden take center stage. This means it’s the perfect time to assess your garden for structural interest. Structure can come in many forms—arbors and trellises, sculptures, well placed screens or landscape walls, or even shapely evergreen trees and hedges.

6. Give Your Roses Some Late-Season Care

Late fall and early winter are a good time to transplant or move roses in Southern California because the weather is typically cooler and there’s more moisture. This provides the ideal conditions for roses to get established. Be sure to give transplanted roses ample water. If you have established roses, stop watering them and let them form rose hips that you can leave on the plant or use for jams, teas, oils, and more. You can also plant bare-root roses at the end of this month and into early winter. Look for bare-root roses in garden centers or from online retailers such as Proven Winners or David Austin.

7. Avoid Cutting Ornamental Grasses & Hydrangeas

Too often, the gorgeous tawny colors of ornamental grasses are cut back in the fall or early winter. Let your ornamental grasses stay until spring and wait to cut them back at the first sign of new growth. Once cut back, the new growth will start growing quickly. This way you can enjoy the beautiful grasses for as long as possible and avoid long periods of cut-back (when grasses look like stumps). It’s too late to cut back hydrangeas. Since hydrangeas bloom on old wood, pruning now would cut off next season’s flowers. Wait to prune until after next season’s blooms fade. Learn more about pruning hydrangeas.

8. Visit an Off-Beat Botanic Garden

There are botanic gardens all throughout Southern California. While there are wonderful, well-known gardens such as The Huntington, there are other lesser-known botanic gardens that are also beautiful to visit in winter. Here are a few to check out: Los Angeles Arboretum (San Marino), San Diego Botanic Garden (Encinitas), Virginia Robinson Gardens (Beverly Hills), Sunnylands (Rancho Mirage), Lotusland (Montecito). Plan a day trip or visit when you make your way to one of these cities. Many of these gardens have cacti, aloe, and other succulent collections that are beautiful in the late-fall and winter months. You may also want to check out our self-guided day trip to three awesome LA gardens.

9. Grow Bulbs Indoors

Consider expanding your indoor bulb growing beyond potted amaryllis. You can force bulbs to grow elegantly in glass containers or set up pots with soil. You can also grow pre-chilled bulbs such as tulips, daffodils, hyacinths, paperwhites, and others in containers filled with soil. Online retailers also have bulb gardens sold as a set.

10. Edge Your Garden Beds

If you have garden beds that abut grass or if you have garden paths through beds, edge them with a garden edger. This will keep your beds and paths looking neat. Clean edges will also help keep plants from being trampled or run over by a lawn mower. It’s also a good time to expand you garden beds if you’ve been thinking of doing so. Cut out and remove grass or other debris. Then cover the soil with 2 to 4 inches of organic mulch. If you need to replace your edging, consider steel edging, plastic edging, or concrete curbing.