10 Gardening Activities for December in the Southwest

1. Continue Planting Bulbs

You can continue planting bulbs through December in the Southwest. The weather is comfortable, so enjoy your time outdoors digging in the soil. If you haven’t bought bulbs yet, you can likely find deeply discounted bulbs at local garden centers or online at places such as Brent and Becky's Bulbs or Van Engelen.

2. Plant Bare-Root Trees

Some of the best bare-root trees to plant this month are bare-root fruit trees such as apple, apricot, peach, pear, persimmon, mulberry, and more. To plant bare-root trees, first remove all the packaging or plastic that the tree was transported in. Then soak the roots of the tree in water for several hours (this hydrates the roots before planting). Next, dig a hole as deep and twice as wide as the roots. Place the tree in the hole and make sure that the root flair is at or slightly above the soil level. It often helps to sprinkle roots with mycorrhizae (a fungi that helps stimulate healthy root growth). Then fill the hole, making sure the tree stays in an upright position, then water it well.

3. Propagate Plants Indoors

Propagating plants has a number of benefits. First, and most obvious, is that you are producing more plants for your garden at little to no cost. Second, you’ll learn more about how plants grow. Third, if you propagate enough plants, you can share them with friends and family. To start propagating plants, begin with the easiest types such as jade plant, rosemary, pothos, philodendron, and succulents. These types of plants can be propagated from stem cuttings and rooted in water before being transplanted to soil for continued cultivation. Watch this video on propagating pothos for a quick overview. For more information on propagating plants, get the book Plant Parenting by Leslie F. Halleck.

4. Continue Frost Preparation

Get out your frost blankets or buy them if cold weather is expected. If you have containers, bring them indoors or into a garage. They can also be wrapped with wool blankets if the freeze isn’t expected to last long. If you have plants growing in raised beds, cover them with a protection tent designed specifically for 4- by 8-foot garden beds. It’s also a good idea to wrap tender shrubs or small trees in burlap to protect them from freezing temperatures. If you are growing roses, cut stems back to 1 to 2 feet and surround them with a wire mesh cylinder. Fill the cylinder with straw or mulch to help insulate them.

5. Avoid Pruning After Frosts

If frost or cold weather damage plants it’s often best to leave dead branches, pads, or leaves on plants such as agaves, bougainvillea, cacti, shrubs, or trees until the threat of more frost has passed. Leaving the dead material can help protect plants from future frost damage. If damaged plant material is a hazard, then remove it as soon as possible or call a professional. To read more about care for frost damaged plants visit the UC Master Gardeners of Butte County blog.

6. Buy a Living Christmas Tree

Many nurseries now stock conifers for people to use as living Christmas trees. Check with your local nursery or try Moon Valley Nurseries, which has locations throughout the Southwest. They have an article about the type of tree they sell that you can use as living Christmas trees.

7. Plant Yuccas, Agaves, and Other Succulents

Yuccas, agaves, and other succulents appreciate the cooler winter weather to get established. If you have hard freezes, then wait to plant until late winter or early spring. In warmer climates with little to no frost, begin planting now. It’s still a good idea to plant cold-hardy varieties such as Yucca rostrata, Agave parryi, Agave ovatifolia, Agave Victoria-reginae, Dasylirion texanum, Hesperaloe parviflora, as well as many other sedums, stonecrops, and sempervivum. Mountain Crest Gardens has a variety of cold-hardy succulents for sale. For large varieties, visit your local nursery.

8. Expand Garden Beds

Late fall and winter months are a good time to expand garden beds. Consider removing areas of lawn that you don’t use frequently and converting them to kitchen gardens, cutting gardens, or herb gardens. This will turn an unused area of your property into a productive and nourishing location. To convert a lawn to a garden bed, remove all the grass. Be sure to get as much of the root system as possible (this can mean removing 4 to 5 inches of grass and roots). For larger areas, use a sod cutter (available to rent from hardware stores and equipment rental facilities). Cover the area with 2 to 4 inches of compost and dig in the soil or use a broadfork to open up the soil.

9. Plant Herbs

Herbs will continue growing in cooler temperatures (if you get frost be sure to give them protection or grow herbs indoors). Add to your herb garden by planting chives, chamomile, parsley, thyme, and winter savory. You can also plant edible shrubs such as bay laurel, lemon verbena, and rosemary.

10. Start Seeds Indoors for Your Vegetable Garden

If you start seeds for edible crops such as tomatoes and peppers this month, then they will be ready to transplant in February or March (a good time to start planting in Arizona and the warmer areas of the Southwest). Try heirloom varieties from seed companies such as Seed Savers Exchange, Baker Creek Heirloom Seeds, or Botanical Interests.