Arizona Garden in December
"The gardening season officially begins on January 1st, and ends on December 31." - Marie Huston
Nowhere is this quote more true than in Arizona. While many parts of the country are dreaming of gardening and circling what they would like to plant in seed catalogs, in Arizona we are harvesting pounds of citrus and vegetables and planting seeds.
The Arizona garden in December is a beautiful place. Chilly morning weather makes afternoon my favorite time of day to be in the garden. Fall planting in September and October yields harvests in the Arizona garden in December. Watch the weather reports carefully and be prepared to cover frost-sensitive plants if we get a freeze. Cool temperatures in December help cool season plants to thrive.
Keep reading for December garden inspiration, a December garden checklist, and a list of which flowers, herbs and vegetables to plant in your Arizona garden in December.
Vegetables growing in the Arizona garden in December
Tomatoes planted in July – September are producing. The cooler temperatures mean they take longer to ripen. Once temperatures drop below 55 degrees at night, the plant will not set new fruit, but fruit on the plant will continue to ripen. Tomato plants are frost-sensitive; cover if temperatures fall below 35 degrees F. December is the time to start tomato seeds indoors for planting in February and March.
Swiss chard is a staple in my garden year round, but the newly-planted tender Swiss chard in the December garden is especially delicious. Continue to harvest outer leaves throughout the winter. Most years many of my Swiss chard plants will produce through the summer as well. I like to replant and begin with fresh plants in the fall.
Flowers growing in the Arizona garden in December
Check at the end of this post for a list of cool-season flowers that do well in Arizona. Many of them can be planted in December. Marigolds that are planted now will thrive until the heat of April or May.
Gaziana is a low-growing, trailing evergreen perennial which grows 6 to 8 inches tall and 2 to 3 feet wide. Grows best in full sun with well-drained soil.
Continue to plant Dianthus. This cold-hardy annual will bloom until temperatures begin to climb in late spring.
Fruit trees in the Arizona garden in December
Cooler temperatures cause citrus fruits to change color, but color is not always an indicator of sweetness. Fruit does not sweeten once picked. Check for ripeness and desired sweetness by sampling the fruit.
- Do not prune citrus this month.
- Water citrus deeply once this month.
Deciduous fruit trees such as peach, pear, and plum are losing their leaves. If all leaves do not fall, strip leaves to encourage dormancy.
- When the scaffold is visible, prune deciduous fruit trees through February. Make cuts carefully and do not remove more than 25 percent of tree.
- December or January is a good time to use a dormant oil spray such as Neem Oil on fruit trees to help prevent pests.
Herbs in the Arizona garden in December
Garlic chives are one of the easiest herbs to grow in Arizona. Harvest young stalks and use in eggs, marinades, and Asian dishes. Divide garlic chives next month if the clumps are overgrown.
Chamomile is an herb in the Asteraceae plant family. A natural remedy for several health conditions that is often consumed as tea made by drying flowers and seeping them in hot water.
Parsley grows well in the cooler weather of December. If you use a lot of parsley, consider succession planting it (planting every 3 weeks).
Arizona garden in December to-do list:
- Start seeds indoors for tomatoes and peppers this month. They will be ready to plant by February or March.
- Begin planning for February and March plantings: order seeds, decide which areas in your garden to plant in (it is best to rotate where you plant your crops each year).
- Plant cold-tolerant trees, bushes and perennials if you must, but protect new plants from freezing temperatures. Visit amwua.org for a list of more than two hundred landscape plants that do well in Arizona’s climate.
- Wait until February to plant frost-sensitive plants such as lantana and hibiscus.
- December in Arizona is a good time to plant fruit trees. Look for varieties which require less than 400 chill hours.
- Water trees and shrubs deeply no more than once every 14-28 days, less often if we get a heavy rain. Wateruseitwisely.com is a helpful resource for landscape watering guidelines.
- Most annual plants are not growing actively and have minimal water needs. Be careful to not over-water this month. Water to a depth of about 6 inches and allow top of soil to dry out before watering again.
- Plants in containers will need less water in December as well. Before watering, check with a moisture meter or make sure top inch or so of soil has dried out.
- Do not prune frost-tender plants this month.
- It is okay to lightly prune spent flowers and dead canes on your established roses in December. Wait until January to remove spent flowers and dead canes in newly-planted roses.
- Prune dead branches out of cold-hardy trees and shrubs. December is a good time to prune dormant woody trees and shrubs. See benefits below.
- Do not fertilize this month.
Protect from freezing temperatures (below 32 degrees F.):
- Have burlap or frost cloth on hand to protect newly-planted citrus and other frost-sensitive plants from frost.
- Plants in containers are more susceptible to freezing temperatures than those in the ground.
- Harvest fruit and clean-up around fruit trees. Fallen fruit and leaves are inviting for pests.
- Save all the leaves that are falling from Ash, Vitex, Elm and other deciduous trees this month. If you planted a winter lawn, the grass clippings combined with fallen leaves are the perfect combination for the compost pile. If you decide not to compost, bag leaves and let them decompose; they will be ready to spread on plants as leaf mulch by spring.
Benefits of pruning woody plants in cool weather:
- Pruning done in warmer months stimulates new growth; when plant is dormant, growth is not stimulated by pruning.
- Pests that can invade pruning cuts are dormant in cooler weather.
- Once leaves have dropped, the overall shape (scaffold) of the tree is easier to see. Spotting crossed or damaged branches is easier.
- Wounds made by pruning in winter will heal quickly in the spring.
What to plant in the Arizona garden in December
- Borage, Catnip, Chamomile, Chives, Cilantro, Dill, Fennell, Garlic Chives, Lavender, Parsley, Rosemary, Thyme
Plant transplants of cold-hardy annuals listed below instead of seeds. Many seeds will not germinate in the cooler month of December; wait to plant seeds until the middle of January.
- African Daisy, Ageratum, Alyssum, Aster, Baby’s Breath, Calendula, Carnation, Dianthus, Echinacea, Forget-Me-Not, Geranium, Gloriosa Daisy, Lobelia, Marigold, Nasturtium, Painted Daisy, Petunia, Poppy, Rudbeckia, Snapdragon, Stock, Straw Flower, Sweet Pea, Verbena