December is the time to begin enjoying your home-grown citrus. (Photo: USDA)

Tasks

• Apply pre-emergent herbicide to lawns and beds later this month
• Deep-water trees and native plants if rainfall has been light

Pruning

• This is the time to work on dormant, deciduous plants - shrubs, vines, grapes, and roses, plus fruit and nut trees
• Crepe myrtles and redbuds may be pruned now
• Cut back and divide perennials

Fertilizing

• No fertilization is recommended this month
• When you do fertilize, always read labels carefully before application. Consult a plant expert at a nursery or a Master Gardener if you have questions

Planting

• This is the beginning of bare-root planting season. It is difficult to visualize the potential of bare-root plants, but they usually come with pictures to give you an idea
• Bulbs, corms, tubers: canna and crocosmia
• Fruits and vegetables: asparagus, cabbage, and bare-root berries
• Trees, shrubs, vines: azalea and camellia

Enjoy now

• Annuals and perennials: snapdragon (Antirrhinum), calendula, and Chrysanthemum Paludosum, Holiday cactus (Schlumbergera)
• Bulbs, corms, tubers: crocus and cyclamen
• Fruits and vegetables: beets, bok choy, chives, and mandarin oranges

Things to ponder

• This is a good time to look through seed catalogs
• Wood ashes are not beneficial in the garden as they increase soil alkalinity

Plant Iceland poppy transplants now for stand-out spring flowers. (Photo: Pxhere)

Tasks

• Monitor rainfall and adjust automatic sprinklers accordingly.  If rainfall is adequate, warm-season grasses require no supplemental irrigation
• Spray stone-fruit, apple, pear, nut, and flowering trees, and roses with dormant oil spray
• Now that the soil is cool and damp, sow seeds of spring wildflowers such as California poppy, clarkia and cornflower

Pruning

• Remove leaves from roses to force them into dormancy in preparation for pruning next month
• Prune out fire blight infections.  Cut the infected shoot or branch at its point of origin

Fertilizing

• Fertilize cool-season annuals, perennials and vegetables with a light, high-nitrogen or organic fertilizer

Planting

• This is not a big planting month unless you have purchased plants or bulbs and have not yet planted them
• Fruits and vegetables: radishes, spinach, plant from seed
• Annuals: forget-me-not (Myosotis), Iceland poppy (Papaver nudicaule), fairy primrose (Primula malacoides)

Enjoy now

• Annuals and perennials: stock (Matthiola), Iceland poppy (Papaver nudicaule)
• Bulbs, corms, tubers: paperwhite (Narcissus)
• Trees, shrubs, vines: heavenly bamboo (Nandina) Maidenhair tree (Ginkgo biloba)
• Fruits and vegetables: persimmons, potatoes, Savoy cabbage, snow peas

Things to ponder

• Be alert for frost warnings and cover tender plants when freezing temperatures are expected. Apply a layer of mulch to protect roots of vulnerable plants
• Amaryllis bulbs will bloom indoors and may do well planted outside with some shade and rich, well-drained soil

Source: Adapted from A Gardener's Companion for the Central San Joaquin Valley, 3rd edition, currently available from Fresno County Master Gardeners for $30. These can be purchased at our demonstration garden - Garden of the Sun (1750 N. Winery (McKinley/Winery), open Mondays, Wednesdays, and Fridays from 9 am to noon, and via email at mgfresno@ucdavis.edu. Gardening questions answered as well at mgfresno@ucdavis.edu. 

Water citrus now to produce a good crop next year. Wait until spring to plant new citrus trees. (Photo: USDA)

Tasks

• Water citrus trees well now to produce a good crop next year
• Check and improve drainage around plants in low areas
• Monitor rainfall and adjust water accordingly to keep soil moist for new plantings

Pruning

• Cut back chrysanthemums to 6 inches
• Prune back spent wisteria canes
• Do not apply any treatments to pruning cuts or other plant wounds because these materials are ineffective and often detrimental

Fertilizing

• Fertilize cool-season annuals, perennials and vegetables with a light, high-nitrogen or organic fertilizer

Planting

• Bare-root planting season begins this month. Consider the hardiness of the rootstock when selecting bare-root fruit trees
• Citrus, avocado, and other frost-tender plants should be planted in spring after the danger of frost has passed
• Fruits and vegetables: asparagus (transplant), onions, parsley
• Annuals: toadflax (Linaria maroccana), stock (Matthiola incana)

When lots of rain is in the forecast, turn off the automatic sprinklers. But when it's dry, don't forget to provide water for new plantings. (Photo: Wikimedia Commons)

• Annuals and perennials: toadflax (Linaria maroccana)
• Bulbs, corms, tubers: paperwhite (Narcissus)
• Trees, shrubs, vines: holly (Ilex), Koreanspice (Viburnum carlesii)
• Fruits and vegetables: Brussels sprouts, citrus, sweet potatoes

Things to ponder

Use trimmings of magnolias, juniper, pine and redwoods for holiday greens. Deodar cedar, spruce and western hemlock lose needles quickly

When shopping for the holidays, consider gifts of gardening tools. (Photo: Alabama Extension)

Tasks

• Monitor ground moisture, especially in beds and under eaves and patios
• Store unused fertilizers and pesticides in a dry place
• Dig and divide overcrowded dahlia tubers and store in a cool, dry place. Replant in late February

Pruning

• Remove dead foliage and stems from dormant perennials
• Prune junipers during cool weather to prevent sunburn
• Prune and trellis caneberries

Fertilizing

• Feed cool weather plants and vegetables

Planting

• The time for fall planting is coming to an end
• Order bare-root roses and perennials from gardening websites or catalogs
• Fruits and vegetables: Lettuce, peas, edible pod peas - plant from seed or six-packs
• Trees, shrubs, vines: fig, walnut (Juglans), crabapple (Malus)
• Annuals: larkspur (Consolida), flowering kale

Enjoy now

• Annuals and perennials: cyclamen, dianthus
• Bulbs, corms, tubers: paperwhite (Narcissus)
• Trees, shrubs, vines: barberry (Berberis)
• Fruits and vegetables: cauliflower, comice pears

Things to ponder

• Enjoy the quiet of the winter garden
• At the end of the month, apply dormant oil spray to deciduous fruit with copper fungicides, to control shot hole disease on twigs
• Avoid overhead irrigation if frost is expected

Historic frost dates

• Zone 8: November 15 through March 15
• Zone 9: December 15 through February 15