Spray peach and nectarine trees with an organic copper-based material before bud swell and bud break to prevent the later development of peach leaf curl, shown above. The product is available at nurseries and home stores. (Photo: Wikimedia Commons)

Tasks

• Peruse seed catalogs looking for disease-resistant strains.
• Shop now for bare root grape and berry vines.
• Deeply water trees and native plants if rainfall has been light.
• Peach leaf curl is best controlled by fixed copper spray at bud swell before bud break.

Pruning

• Crepe myrtles and redbuds may be pruned now.
• Do not apply any treatment to pruning cuts or other wounds because these materials are ineffective and often are detrimental.
• Wait to prune spring-flowering shrubs until after they bloom.

Planting

• Planting annuals and perennials for spring bloom starts next month, look now for new varieties of spring vegetables and summer blooming bulbs.
• Sow seeds of summer annuals and vegetables in flats in a protected location or indoors.

Enjoy now

• Annuals and perennials: Iceland poppy (Papaver nudicaule), camellias, Callistemon ‘Little John.'
• Bulbs, corms, tubers: freesia, daffodil, crocus.
• Fruits and vegetables:  lemon, navel orange and spinach.

Things to ponder

• Sharp tools make cleaner cuts. Clean and maintain pruning equipment.
• This is a good time to divide African violets for early spring bloom.
• When the soil is cold and wet, citrus trees and other plants may not be able to make efficient use of iron, nitrogen and other nutrients even though there is an adequate supply available in the root zone. This problem usually disappears when soil conditions improve, and no further action is required.
• Automatic sprinklers should be turned off completely during periods of rainfall.

Citrus fruit is abundant in the winter. Enjoy now! (Photo: PickPik)

Tasks

Rainfall may not reach areas under eaves and overhangs. Check soil moisture and apply supplemental water if needed.

Apply preemergent herbicide to lawns and beds in the latter part of the month to control crabgrass and other early germinating weeds.

Pruning

Finish pruning roses and deciduous fruit trees by the end of the month.

At bud swell, spray deciduous fruit, almond trees and roses with dormant oil to prevent and control over-wintering insects.

Prune out fire blight infections. Remove the infected shoot or branch at its point of origin.

Fertilizing

Fertilize spring-flowering perennials, annuals, bulbs and shrubs.

Yellow foliage, particularly the youngest leaves, may be attributed to iron deficiency. Yellowing in older leaves may be attributed to nitrogen deficiency.

Prune out shoots and branches that show symptoms of fire blight infection. (Photo: UC IPM)

Group plants with similar water needs together.

This is a good time to move perennials, shrubs or small trees.

Spring planting season begins next month. Work on your garden plans and be ready to start next month.

Enjoy now

Annuals and perennials: feverfew (Chrysanthemum parthenium), toadflax (Linaria maroccana), cyclamen.

Citrus fruits are abundant now - use them to brighten up the winter menu.

Things to ponder

Leave frost-damaged growth on tender plants as protection until the danger of frost is past. Begin pruning as new growth emerges.

January is time to plant roses. (Photos: Jeannette Warnert)

Tasks

• New roses of many varieties are featured in magazines and articles - or view them online. Look for those you like, select ones that are suitable for your area, and buy them bare root. Consider the aesthetic qualities of roses as well as size when placing them in the landscape.
• Soak bare root plants for two to four hours in a bucket of water to rehydrate roots before planting.

Pruning

• Prune existing roses to remove diseased and damaged wood, regulate size and shape, and improve bloom quality.
• Use clean, sharp tools to avoid splitting or crushing canes and branches, cut one-quarter inch above a bud or leaf joint and make cuts at a 45° angle to the branch.
• Leave three to five canes in a vase-shaped configuration when pruning hybrid teas, grandifloras or floribundas.
• Remove leaves from roses to force dormancy, if this task has not already been done.

Fertilizing

• Roses have a long growing and blooming season here, so a regular feeding schedule is important. Usual fertilizing months for established plants are February and September.
• At planting time, apply a rose fertilizer to new plants.

Planting

• This is the time to move and transplant roses. Prepare a hole two feet wide and deep enough to keep the graft above ground level.
• Make a mound of soil in the middle of the hole. Spread the roots as much as possible and place the rose on the mound. Add soil until the hole is about two-thirds full then fill it with water and let it soak in. Finish filling the hole and water again. Use the regular soil and tamp down to remove any air pockets.
• Fertilize with a rose planting product and follow label instructions. Remember to water regularly if there has not been any rain.
• Dress beds with organic material and mulch to control weeds.
• Keep mulch back from the base of the rose plant.
• Water if rainfall is less than normal.

Enjoy now

• Survey the completion of the first task of the new year, pruning roses, and look forward to the first spring rose in April.

Things to ponder

• Roses grow to different heights depending on the variety - from the lower landscape/shrub roses and floribundas to the taller hybrid tea and grandifloras. Keep this in mind when placing roses in your garden.

Roses are available in many varieties at nurseries, garden centers and online in January.

Woodsorrel, the shamrock-like plant in the foreground pictured in December, is a perennial herb that is not native to California. Some people like its yellow flowers in the spring, but it can be invasive. (Photos: Jeannette Warnert)

Tasks

• Control cool-season weeds before they mature and go to seed.
• Plants planted last spring and fall may need water if rainfall has been inadequate.
• Run sprinklers periodically through their cycles to maintain clean lines and to exercise the valves.

Pruning

• When harvesting blooms for arrangements, make cuts with an eye toward shaping the plant.
• Prune and shape dormant deciduous plants – shrubs and perennials.
• Cut away 50% of last year's growth on peaches and nectarines.
• Remove leaves from roses in January to force the plant into dormancy. This is not necessary with shrub or groundcover roses.

Fertilizing

• Apply nitrogen fertilizer to citrus trees prior to bloom.
• Always read labels carefully before applying fertilizer. Use only if necessary.

To control a nutsedge infestation, pull out the plants by hand, ensuring that the tubers on the roots are removed.

• Bare root planting season continues.
• Peas (both edible and decorative varieties) can be planted this month.  Before planting, soak dried peas between damp paper towels in a shallow dish. Cover loosely with plastic and keep towels moist.  Plant seeds when they're just beginning to sprout.

Enjoy now

• Annuals and perennials: Primrose (Primula polyantha), English primrose (Primula vulgaris), pansy (Viola), sweet violet (Viola odorata), Poinsettia (Euphorbia pulcherrima).
• Bulbs, corms, tubers: squill (Scilla bifolia), ‘Paper White' narcissus (Tazetta daffodils).
• Trees, shrubs, vines: Anthony Waterer spirea (Spiraea japonica), bridal wreath spirea (Spiraea prunifolia).
• Fruits and vegetables: lemons, navel orange, parsley.

Things to ponder

• Frost is possible when it is clear enough to see the stars.  Remember to leave frost-damaged foliage until danger of frost has passed. Prune later if needed.
• Remove fallen camellia blooms promptly to prevent petal blight on next year's flowers.