December Gardening Tips

As the days grow cooler and shorter, plant growth comes to a near halt this time of year. Be prepared to protect your plants from frost and possibly some dry heat if a heat wave comes through. With all the holiday planning this time of year, you may find yourself too busy to work in the yard. Don’t worry; most plants will do fine with little help right now. Hopefully you prepared them for winter in the fall and can now sit back and relax. You can still get away with planting most fall plants, but don’t wait to long. You can get an early start on planting bare roots or at least shop for them now.

What to Plant

  1. Choose and plant camellias and azaleas this month while they are in bloom. They are best planted while in bloom. You’ll be able to see which colors you like best before you buy them at the nursery.
  2. Continue to plant winter herbs. Cilantro, chickweed, chives are all good choices.
  3. Continue to plant cool season vegetables that can tolerate cooler temperatures. Broccoli, Brussels sprouts, cabbage, cauliflower, celery, kale, kohlrabi, mustard, lettuce and other greens, root crops like beets, carrots, radishes and turnips are all good choices.
  4. Finish planting any spring-flowering bulbs that do not require pre-chilling. Try to plant before the end of December. If you plant too late the flowers will be fewer and smaller. Tulips, crocus and hyacinths should be refrigerated for 6 – 8 weeks before planting. They need cooler ground temperatures so start planting around Christmas unless there’s a heat wave. If a heat wave occurs wait until it cools down again, but plant before mid-January.
  5. Continue to plant Wildflowers from seed. We recommend Stover® Seeds for their quality. A wildflower can be considered any annual or perennial that reseeds itself; fall cosmos, gaillardia, annual gypsophila, foxglove, larkspur, nasturtiums and violas. Varieties that grow wild in California are Chinese houses, several Clarkias, chocolate-bell fritillarias, desert bluebells, California poppies, mariposa lilies, owl’s clover and others.
  6. Continue to plant California Natives. For more information on natives visit Las Pilitas Nursery – When to Plant
  7. Now is a good time to plant or repair lawns with cool season grasses! Whether you are starting a new lawn or repairing thin areas of your existing turf, we have many options available in different sizes to fit your growing area.
  8. Grangetto’s Tall or Dwarf Fescue Seed
  9. Marathon® I or Marathon® II Lawn Seed
  10. Am Sod® Tall or Dwarf Fescue Sod
Feeding and Maintenance


  1. Keep Lawns Healthy: Rake falling leaves from lawns as leaves could impede lawn growth. If a lawn is in need of repair – sow in annual rye seeds to cover brown spots and to introduce new growth. After seeding, scatter a light covering of soil amendment and water thoroughly.
  2. Feed cool-season lawns with Best® Nitra King 19-4-4, but don’t feed warm-season lawns (except for Bermuda that’s over-seeded with winter ryegrass)
  3. Control rust on cool-season lawns by fertilizing and mowing them, including Bermuda that’s over-seeded with winter rye grass.
  4. Mow cool season lawns as needed including bermuda that is over-seeded with winter ryegrass. Do not mow warm-season lawns, except St. Augustine (if it continues to grow).

Plants, Trees and Shrubs

  1. VEGETABLES – Between harvests you can still plant most cool-season vegetables such as broccoli, Brussels sprouts, cabbage, cauliflower, celery, kale, kohlrabi, mustard, lettuce and other greens, and root crops like beets, carrots, radishes, and turnips. Harvest winter vegetables as soon as they mature. Clean-up old, fallen veggies and fruit as needed to prevent disease.
  2. HERBS – You can prune your rosemary, sage & lavender to shape it. Harvest lemongrass, chaste berries, ginkgo leaves and fennel seed. Plant perennials such as rosemary, lavender and thyme.
  3. FRUIT TREES & VINES – Provide frost protection to young avocado, citrus and other subtropical fruit trees. We have many options available for frost protection. Prune cane berries other than low-chill raspberries. Grapes. Prune Grapes from December through early January.
  4. DECIDUOUS FRUIT TREES – Prune trees and vines after their foliage has dropped. Spray dormant deciduous trees and vines with Horticultural Oil to kill scale, insects, spider mites and other over-wintering pests. Spray peach and nectarine trees with a recommended fungicide to control peach leaf curl. Order low chill, bare root trees and vines to plant in now or January.
  5. FLOWERS & PLANTS – Feed cool season flowers with a complete fertilizer for growth and bloom. Use Gro Power® Flower N’ Bloom. Feed shade plants for bloom; give adequate light. Purchase poinsettias early in the month. Cut off flower spikes that have bloomed from dwarf foxgloves and delphiniums.
  6. ROSES – Buy new bare root roses around the second to third week of December. Plant bare root roses after soaking the roots in a bucket for at least 24 hours. If the rose comes in a cardboard container, remove and trim any broken roots before soaking in water.
  7. FERNS – Most ferns aren’t growing much this time of year so don’t over water them. Trim off dead fronds. Don’t feed until spring.
  8. PLUMERIA – You should have prepared your plumerias for winter dormancy by now. Be sure to place them next to a building or under a covered patio if they are in pots. Bring plants inside in frost areas. Be sure to protect outside plumerias that are in ground with frost cloth when frost or freeze is expected. Once leaves are dormant, hold back on water and fertilizer. You won’t need to feed them again until spring.
  9. CAMELLIAS – Continue feeding your camellias this month through January with Gro Power Flower N’ Bloome 3-12-12 for bigger blooms. Remove all but the largest bud where bud clusters exist. Disbudding provides larger but fewer blooms. Pick up blooms that fall to the ground to prevent diseases such as petal blight. Feed with an iron supplement such as Ironite for dark green leaves. If rains are heavy, cut back on watering. Just remember not to let your plants dry out if rains are not adequate.

    Camellias are in their dormant season (October – March). Move, re-pot or bare-root and re-pot now. When planting in the ground or a pot, plant one inch higher than soil level. Camellias don’t like their crowns covered. Be sure to check the tag on your camellia to check if the prefer sun or shade.

  10. BEGONIAS – Continue watering if rains are not adequate. Clean out spent blooms and dead leaves. Keep roots covered by adding soil or mulch. Spray for pests, insects or mildew. Feed your plants lightly several times a month. If you’re using a slow release fertilizer you do not need to feed as often.
  11. BROMELIADS – Reduce watering and stop fertilizing your outdoor plants during the cold months. You may continue to fertilizer your greenhouse/indoor plants year round. Protect your plants from frost, wind or hail. Use shade cloth to protect from hail or DeWitt Frost cloth during freezing temperatures.
  12. ORCHIDS – Look for aphids and other pests on outdoor plants. Water plants before noon and protect outdoor orchids from evening moisture. Do not overwater outdoor plants. Water and fertilize less in winter. Train developing spikes on cymbidiums. Some cymbidiums start to bloom in December, but most bloom between February and March. Continue feeding cymbidiums until flowers open with Orchid Food. Keep them damp but not soggy.
  13. PELARGONIUMS – Start a pruning program to get fuller plants and more blooms in the spring. Start new plants from cuttings. Clean plants by removing dead, damaged or older leaves. Watch for geranium rust in high humidity areas and treat. Do not let plants go dry if rains are not adequate.
  14. DAHLIAS – Allow the plants to go dormant. Hold water and fertilizer. Lift and store dahlias for winter. When dahlias have gone totally dormant, dig up the tubers. First cut back the tops to six inches, dig around each plant, then carefully lift each clump with a garden fork. Cut the tops back to two inches and layout the whole clump on newspapers to dry. Continue to dry these clumps in a dry shady place for two to three days then dust the clumps with sulfur and pack in perlite. Divide the clumps in the spring when growth begins. Make sure each section has an "eye" (growth bud).
  15. NATIVE PLANTS – If you haven’t already prepared your native landscape for winter & spring, do so now. Prune and deadhead the sages and buckwheats. Do not prune toyon because it will still look very good in December. Dig new holes for plantings. Fill with water several times and allow to drain before planting. Little or no soil amendments should be used. The next couple months are the best for establishing your native plant garden.
  16. TREES & SHRUBS - Open up spaces in dense trees to allow wind to pass through. Prune acacias. Stake young trees loosely so they can develop strong trunks. Prune wisteria by cutting off unwanted long twiners. Prune roots of vines that fail to bloom.
  17. TROPICALS – Don’t prune tropicals.
  18. CLEAN UP – Continue cleaning dead leaves and debris.
  19. PREPARE FOR RAIN AND WIND – Get ready for winter rains. Grangetto’s carries a full line of erosion materials such as, straw wattles, straw mats, silt fence, and jute netting. Grangetto’s also carries rain gear, such as rain boots & suits, tarps and plastic sheeting.
  20. REPAIR DRAIN SYSTEMS – Repair drain systems if needed. Grangetto’s carries a variety of drainage supplies, such as Drain Pipe, Grates and Boxes.
  21. MULCH, MULCH, MULCH – If you haven’t already, apply a layer of mulch on flower beds and around trees and shrubs 2-3 inches around the base of plants. It reduces weeds, conserves moisture, and prevents disease. Great stuff!


  1. As the weather cools and days are shorter, reset your irrigation timer to water less frequently. However, don’t change the number of minutes the system waters each time.
  2. In many areas, trees and shrubs will need watering only every week to week and a half, and citrus trees just once a month. But, be sure not to let citrus dry out during times of frost/freeze.
  3. Continue periodic and thorough irrigation of fruit trees to maintain adequate soil moisture until winter rains begin.
  4. Reduce watering to your roses so that the rose will survive but not be encouraged to grow.
  5. Don’t water succulents growing in the ground.
  6. Remember to keep all bulbs, especially potted ones, well watered.
  7. This is the growing season for California Natives so if the weather is dry be sure to water your plants. You can also prune your native plants now to improve their shape.
  8. Now is a perfect time to start planning on how you are going to save water in your landscape, if you haven’t already. Installing or retrofitting an existing irrigation system to utilize the most up-to-date technology will help you save water. Grangetto’s can help you make the SMART WATER CHOICE in your landscape. Call us or stop by your favorite location so we can help! Here are some water saving devices
  9. Be sure to follow your local watering restrictions and guidelines

Pests to Watch out For

  1. Gophers – Use Wilco® Gopher Getter. Use the Lewis Lifetime® Gopher Probe to accurately put the bait where the gopher will eat it.
  2. Lawn pests – Use Bayer® Multi-Insect Killer or Spectracide® Triazicide
  3. Squirrels – Use Wilco® Squirrel Bait & Bait Station or for live trapping use the Squirrelinator®.
  4. Rats & Mice – Use baits, snap traps or sticky traps.
  5. Raccoons: Use Havahart® traps.
  6. Caterpillars – Use Safer® Caterpillar Killer, Monterey® Garden Insect Spray or Green Light® Lawn & Garden Spray with Spinosad.
  7. Rose Pests – Use Bayer® All-in-One Rose & Flower Care or Bayer® 3-in-1 Insect Disease and Mite Control.
  8. Fruit Tree Pests – Use Monterey® Garden Insect Spray to combat caterpillars and other listed pests on fruit trees, vegetables and ornamentals. It is OMRI listed for Organic Use too.
  9. Weeds – Hand pull weeds in garden beds. Use Bonide® Crabgrass Preventer or Bayer® Season Long Weed Control in lawns. Use Green Light® Amaze in ornamentals & flower beds. For non-selective areas, use Roundup® or QuickPro® products. Be sure to use a good sprayer such as Hudson® Sprayers.

Note: All information provided is based on typical season, weather and environmental statistics. These tips are provided for information purposes only and to be used as a general guide. Products/Brands mentioned may be discontinued at anytime and not guaranteed in-stock. Grangetto’s invites you to contact us or visit one of our locations for more specific care instructions.

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